A new energy vehicle cable material and its preparation method

Abstract

The invention relates to a new energy automobile cable material and a preparation method thereof, and belongs to the technical field of automobile cables. The new energy automobile cable outer sheath material is obtained by preparing the modifier, blending the modifier and polyethylene, carrying out melt extrusion and then carrying out irradiation crosslinking, when an outer sheath is combusted, halogen-free flame retardance is realized through phosphorus-silicon synergism, flame spreading can be delayed when a new energy automobile cable is on fire, and the flame retardance of the new energy automobile cable is greatly improved, so that the service life of the new energy automobile cable is prolonged, and the service life of the new energy automobile cable is prolonged. The phosphate ester structure can be coordinated with copper ions on the surface of the shielding layer, the bonding capacity of the shielding layer and the polyethylene sheath is improved, permeation of moisture and oxygen is reduced, and chemical corrosion is inhibited, so that long-term stability of the shielding effectiveness of the new energy cable is ensured; by improving the crosslinking density and the compatibility of the base material, the mechanical property and the heat resistance of the cable outer sheath are enhanced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of automobile cable, in particular, relates to a new energy automobile cable material and a preparation method thereof, more particularly, relates to a new energy automobile cable outer sheath material and a preparation method thereof. BACKGROUND

[0002] New energy vehicles, especially pure electric vehicles, have much higher requirements for cable performance than traditional vehicles. There are high-voltage and large-current power cables and high-power charging cables inside. The working environment of these cables is harsh, making it difficult for traditional materials to meet the demand.

[0003] Traditional new energy vehicle charging cables mostly use polyvinyl chloride resin and other materials as outer sheaths. The flame-retardant performance of such materials is limited, and the heat resistance is general. In addition, a large amount of toxic smoke and corrosive gas will be generated during combustion, which poses a great safety hazard. Polyethylene is often chosen as a modified base material for cables due to its excellent electrical insulation and chemical stability. In the prior art, metal hydroxide flame retardants are usually added, but there are problems such as insufficient flame-retardant efficiency and excessive addition amount leading to a decline in other performance. In addition, new energy vehicles have high temperatures during charging or high-load operation, and cable materials are prone to thermal aging, surface embrittlement and cracking under long-term high temperature, which affects the electrical insulation performance and service life of the cable. At the same time, there are interface gaps between the copper-plastic composite shielding layer and the outer sheath in the cable, which cannot completely block the penetration of external corrosive media, causing corrosion that will lead to failure of the shielding function and ultimately cause failure of the entire high-voltage cable system.

[0004] Therefore, the application provides a new energy automobile cable material and a preparation method thereof. SUMMARY

[0005] The application aims to provide a new energy automobile cable material and a preparation method thereof to solve the problems mentioned in the background.

[0006] The application can achieve the above-mentioned purposes by the following technical solutions. A preparation method of a new energy automobile cable material, comprising the following steps: Firstly, phosphoric acid, vinyl oxirane and tetrahydrofuran are added to a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is started, and the reaction is carried out at 60-90℃ for 1-3h. After the reaction is completed and cooled to room temperature, the solvent is removed by rotary evaporation, and then the product is washed with saturated sodium bicarbonate solution, and then dried and column chromatography elution to obtain a flame-retardant monomer; Second step, the flame retardant monomer, silane coupling agent, potassium carbonate, acid binding agent and acetonitrile are added into a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is started, and the reaction is carried out at 60-80℃ for 8-12h. After the reaction is completed and the product is cooled to room temperature, dichloromethane is used for extraction, and the organic phase is reserved. Then, the organic phase is washed with saturated brine and deionized water, and then dried and rotary evaporated to obtain the modifier. Third step, the high-density polyethylene, low-density polyethylene, fumed silica, modifier, zinc borate, lubricant and antioxidant are mixed and then added into a screw extruder for melt extrusion. Then, the melt extrusion product is subjected to radiation crosslinking in an electron accelerator. After the crosslinking is completed, the product is transferred into a vacuum oven for vacuum treatment at 80-100℃ for 30-40h to eliminate internal stress, thereby obtaining the new energy vehicle cable outer sheath material.

[0007] Further, the mass fraction ratio of phosphoric acid, vinyl oxirane and tetrahydrofuran in the first step is 1.5-3:2.7-5.5:16-20.

[0008] Further, the silane coupling agent in the second step is at least one of chloropropyl triethoxysilane and chloropropyl trimethoxysilane.

[0009] Further, the acid binding agent in the second step is at least one of pyridine, 4-dimethylaminopyridine and triethanolamine.

[0010] Further, the mass fraction ratio of the flame retardant monomer, silane coupling agent, potassium carbonate, acid binding agent and acetonitrile in the second step is 2.5-5.5:5.5-9.5:4-8:5-10:80-100.

[0011] Further, the lubricant in the third step is at least one of polyethylene wax and oxidized polyethylene wax.

[0012] Further, the temperature of melt extrusion in the third step is 150-180℃.

[0013] Further, the radiation dose in the radiation crosslinking in the third step is 70-90kGy, and the radiation time is 10-15s.

[0014] Further, the antioxidant in the third step is at least one of antioxidant 300, antioxidant 1010 and antioxidant 3114.

[0015] Further, the mass fraction ratio of the high-density polyethylene, low-density polyethylene, fumed silica, modifier, zinc borate, lubricant and antioxidant in the third step is 65-75:25-35:15-20:5-10:3-5:0.4-0.6:0.4-0.6.

[0016] The new energy vehicle cable material is prepared by any of the preparation steps.

[0017] The beneficial effects of the present application are: The outer sheath material of the new energy vehicle prepared by the present application can promote the formation of carbon on the surface of the polymer during combustion, thereby isolating heat and oxygen, and silicon can form a strong ceramic protective layer to further strengthen the carbon layer. The two work together to form an efficient composite flame-retardant mechanism, achieving halogen-free flame retardation. The excellent flame-retardant performance of the outer sheath can delay the spread of flames when the new energy vehicle cable encounters fire, thereby avoiding rapid expansion of the fire and causing greater safety accidents. At the same time, it can reduce the release of toxic and harmful gases during cable combustion, giving more escape time to the people inside the vehicle and reducing the risk of secondary injury.

[0018] The new energy vehicle cable outer sheath material of the present application will wrap the shielding layer composed of copper braid or copper foil. The phosphate structure in it can coordinate with the ions on the surface of the shielding layer, improve the bonding ability of the copper braid and the polyethylene sheath, reduce the interfacial gap, reduce the penetration of moisture and oxygen, and inhibit the occurrence of chemical corrosion, thereby ensuring the long-term stability of the shielding effectiveness of the new energy cable, ensuring the reliability of the electrical system of the new energy vehicle, and improving the quality and safety of the new energy vehicle.

[0019] The modifier of the present application contains multiple double bonds, which can bond with polyethylene from the molecular level after irradiation crosslinking, thereby improving the overall crosslinking density of the material. The siloxane in it improves the dispersion stability of fumed silica, avoids performance defects caused by agglomeration, and both work together to significantly improve the mechanical properties and heat resistance of the cable outer sheath. The new energy vehicle cable can better resist vibration, friction and extrusion during driving, and can also avoid aging failure caused by high temperature and external force, thereby prolonging the service life of the cable and reducing the risk of short circuit, and ensuring stable power transmission. DETAILED DESCRIPTION

[0020] The technical solutions of the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0021] Among them, all raw materials of the present application have no special restrictions on their sources, and can be purchased on the market or prepared according to conventional methods well known to those skilled in the art.

[0022] Example 1

[0023] A preparation method of a new energy vehicle cable material, comprising the following steps: The first step, 1.5 g of phosphoric acid, 2.7 g of vinyl oxirane and 16 g of tetrahydrofuran are added to a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is started, and the reaction is carried out at 60°C for 3 h. After the reaction is completed and cooled to room temperature, the solvent is removed by rotary evaporation, and then the product is washed with saturated sodium bicarbonate solution, and then dried and column chromatography elution to obtain a flame retardant monomer; The second step, 2.5 g of flame retardant monomer, 5.5 g of chloropropyl triethoxysilane, 4 g of potassium carbonate, 5 g of pyridine and 80 g of acetonitrile are added to a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is started, and the reaction is carried out at 60°C for 12 h. After the reaction is completed and the product is cooled to room temperature, it is extracted with dichloromethane and the organic phase is retained, then the organic phase is washed with saturated brine and deionized water, and then dried and rotary evaporated to obtain a modifier; The third step, 65 g of high-density polyethylene, 35 g of low-density polyethylene, 15 g of fumed silica, 5 g of modifier, 3 g of zinc borate, 0.4 g of polyethylene wax and 0.4 g of antioxidant 300 are mixed and then added to a screw extruder for melt extrusion at 150°C. Then it is irradiated and crosslinked in an electron accelerator at a dose of 70 kGy for 10 s, and then placed in a vacuum oven at 80°C for 40 h to eliminate internal stress, thereby obtaining a new energy automobile cable sheath material.

[0024] A new energy automobile cable material is prepared by the above preparation steps.

[0025] Example 2

[0026] A method for preparing a new energy automobile cable material, comprising the following steps: The first step, 2.25 g of phosphoric acid, 4.1 g of vinyl oxirane and 18 g of tetrahydrofuran are added to a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is started, and the reaction is carried out at 75°C for 2 h. After the reaction is completed and cooled to room temperature, the solvent is removed by rotary evaporation, and then the product is washed with saturated sodium bicarbonate solution, and then dried and column chromatography elution to obtain a flame retardant monomer; The second step, 4 g of flame retardant monomer, 7.5 g of chloropropyl trimethoxysilane, 6 g of potassium carbonate, 7.5 g of 4-dimethylaminopyridine and 90 g of acetonitrile are added to a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is started, and the reaction is carried out at 70°C for 10 h. After the reaction is completed and the product is cooled to room temperature, it is extracted with dichloromethane and the organic phase is retained, then the organic phase is washed with saturated brine and deionized water, and then dried and rotary evaporated to obtain a modifier; Third step, 30g high density polyethylene, 30g low density polyethylene, 17.5g fumed silica, 7.5g modifier, 4g zinc borate, 0.5g oxidized polyethylene wax and 0.5g antioxidant 1010 are mixed and then added to a screw extruder for melt extrusion under the condition of 165℃, then irradiated and crosslinked in an electron accelerator under the condition of 80kGy for 12.5s, and then placed in a vacuum oven for vacuum treatment at 90℃ for 35h to eliminate internal stress, thereby obtaining a new energy automobile cable outer sheath material.

[0027] A new energy automobile cable material is prepared by the above preparation steps.

[0028] Example 3

[0029] A preparation method of a new energy automobile cable material, comprising the following steps: First step, 3g phosphoric acid, 5.5g vinyl oxirane and 20g tetrahydrofuran are added to a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is started, and the reaction is carried out at 90℃ for 1h. After the reaction is completed and the temperature is cooled to room temperature, the solvent is removed by rotary evaporation, and then the product is washed with saturated sodium bicarbonate solution, and then dried and column chromatography elution to obtain a flame retardant monomer; Second step, 5.5g flame retardant monomer, 9.5g chloropropyl triethoxysilane, 8g potassium carbonate, 10g triethanolamine and 100g acetonitrile are added to a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is started, and the reaction is carried out at 80℃ for 8h. After the reaction is completed and the product is cooled to room temperature, dichloromethane is used for extraction and the organic phase is reserved, then the organic phase is washed with saturated brine and deionized water, and then dried and rotary evaporated to obtain a modifier; Third step, 75g high density polyethylene, 25g low density polyethylene, 20g fumed silica, 10g modifier, 5g zinc borate, 0.6g polyethylene wax and 0.6g antioxidant 3114 are mixed and then added to a screw extruder for melt extrusion under the condition of 180℃, then irradiated and crosslinked in an electron accelerator under the condition of 90kGy for 15s, and then transferred to a vacuum oven for vacuum treatment at 100℃ for 30h to eliminate internal stress, thereby obtaining a new energy automobile cable outer sheath material.

[0030] A new energy automobile cable material is prepared by the above preparation steps.

[0031] Comparative Example 1 The difference between this comparative example and Example 2 is that the modifier is replaced by a commercially available phosphate ester flame retardant APP, and the remaining raw materials and preparation steps remain unchanged.

[0032] Experimental Example 1 The outer sheath in Examples 1-3 and Comparative Example 1 was subjected to performance testing. The tensile strength and elongation at break of the outer sheath of each group of new energy vehicle cable were tested in accordance with GB / T 2951.21-2008 "General test methods for cable and optical cable insulation and sheath materials". The tensile strength retention rate and elongation at break retention rate of the outer sheath of each group of new energy vehicle cable after constant temperature treatment at 150-160°C for 1h were tested in accordance with GB / T 15065-2009 "Black polyethylene plastics for electric wires and cables". The flame retardant grade of the outer sheath of each group of new energy vehicle cable was tested in accordance with GB / T 19666-2019 "General requirements for flame-retardant and fire-resistant electric wires and cables or optical cables". The peeling strength between the outer sheath and the metal shielding layer of each group of new energy vehicle cable was tested in accordance with GB / T 17737.313-2018 "Coaxial communication cables" at a peeling angle of 180° and a constant tensile speed of 90-105mm / min. The test results are shown in Table 1.

[0033] Table 1

[0034] As can be seen from Table 1, compared with Comparative Example 1, Examples 1-3 have higher tensile strength, elongation at break, tensile strength retention rate, elongation at break retention rate, flame retardant grade and peeling strength, indicating that the mechanical properties, heat resistance, flame retardant properties and bonding force with the metal shielding layer of Examples 1-3 are all better than those of Comparative Example 1. It can be seen from Comparative Example 1 that the addition of the modifier can effectively improve the mechanical properties, ultraviolet resistance, flame retardant properties and bonding force with the metal shielding layer of the new energy vehicle cable outer sheath material.

[0035] The new energy vehicle cable material and the preparation method thereof provided by the present application are described in detail above. In this paper, specific examples are applied to describe the principles and implementation modes of the present application. The above description of the examples is only used to help understand the method and core idea of the present application, including the best mode, and also enables any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make some improvements and modifications to the present application without departing from the principles of the present application. In particular, as long as there is no structural conflict, each feature in the disclosed embodiments of the present application can be combined with each other in any way. The present application is not limited to the specific embodiments disclosed in the specification, 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. 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.

2. The method for preparing a new energy vehicle cable material according to claim 1, characterized in that, The mass ratio of phosphoric acid to vinyl ethylene oxide is 1.5–3:2.7–5.

5.

3. The method for preparing a new energy vehicle cable material according to claim 1, characterized in that, The silane coupling agent is at least one of chloropropyltriethoxysilane and chloropropyltrimethoxysilane.

4. 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.

5. The method for preparing a new energy vehicle cable material according to claim 1, characterized in that, 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.

6. 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.

7. 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℃.

8. 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.

9. The method for preparing a new energy vehicle cable material according to claim 1, characterized in that, 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.

10. 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 9.