Automobile fast charging cable and processing technology

Abstract

The application relates to the field of cables, in particular to an automobile fast-charging cable and a processing technology, which solves the problems that the heat resistance and the flame retardance of the existing automobile cable sheath material are poor, and the service life and the use safety of the automobile fast-charging cable are seriously affected; the processing technology takes the addition of a polycyanogroup DOPO-based compound and a heat-resistant reinforcing agent as core additives to the cable sheath material, the two additives produce a synergistic effect, the heat resistance and the flame retardance of the cable sheath material can be obviously improved, the stability and the safety of the cable sheath material under extreme environments are realized, and the service life and the use safety of the automobile fast-charging cable are improved, so that the processing technology has extremely high practical value and market prospect.

Description

Technical Field

[0001] This invention relates to the field of cables, specifically to a fast charging cable for automobiles and its processing technology. Background Technology

[0002] In today's society, with the rapid development of electric vehicles, DC fast charging technology for electric vehicles is rapidly advancing towards higher voltage and higher current, and the working conditions of fast charging cables are becoming increasingly stringent. During the charging process, the cable sheath not only needs to withstand the heat conduction of the cable core, but also the heat generated by external environments such as sunlight exposure, and its operating temperature requirements are becoming increasingly stringent.

[0003] Traditionally, the sheathing materials used for automotive cables are mainly polymers such as PVC (polyvinyl chloride) and PE (polyethylene). However, these polymers have poor heat resistance and are prone to aging when exposed to high temperatures for extended periods, thus shortening the lifespan of the charging cables. Furthermore, they are severely inadequate in flame retardancy, failing to meet stringent fire safety standards and unable to prevent the spread of fire in the event of a fire, threatening vehicle safety. Therefore, developing a fast-charging cable for automobiles and its processing technology is of significant practical importance. Summary of the Invention

[0004] In order to overcome the above-mentioned technical problems, the purpose of this invention is to provide a fast charging cable for automobiles and its processing technology, which solves the problem that the heat resistance and flame retardant properties of existing automobile cable sheath materials are poor, which seriously affects the service life and safety of automobile fast charging cables.

[0005] The objective of this invention can be achieved through the following technical solutions: In a first aspect, this application provides a fast charging cable for automobiles, including a copper core wire and a temperature-resistant and flame-retardant sheath on the surface of the copper core wire; The temperature-resistant and flame-retardant sheath comprises the following components in parts by weight: 20-25 parts LLDPE plastic, 16-18 parts EVA plastic, 10-12 parts POE plastic, 1-7 parts polycyanoDOPO compound, 8-12 parts heat-resistant reinforcing agent, 0.5-0.7 parts antioxidant, and 1.1-1.5 parts polyethylene wax; The polycyanoDOPO-based compound is prepared by the following steps: Step a1: Melamine, 4-cyanobenzaldehyde, glacial acetic acid, and anhydrous ethanol were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 20-25℃ and 200-300 r / min for 20-30 min. Then, the temperature was raised to 80-90℃ and the mixture was stirred for 8-10 h. After the reaction was completed, the product was cooled to room temperature. The solvent was then removed by rotary evaporation. The product was washed 2-3 times with ethanol solution and then placed in a vacuum drying oven at 70-80℃ for 3-5 h to obtain a polycyanoSchiff base compound. Step a2: Add the polycyano-Schiff base compound, DOPO, and anhydrous ethanol to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir the reaction at 20-25℃ and 200-300 r / min for 10-20 min. Then raise the temperature to 80-90℃ and continue stirring for 10-15 h. After the reaction is complete, cool the reaction product to room temperature, then filter under vacuum. Wash the filter cake 2-3 times with distilled water and then place it in a vacuum drying oven at 70-80℃ for 6-8 h to obtain the polycyano-DOPO-based compound.

[0006] In a preferred embodiment of the present invention, the ratio of melamine, 4-cyanobenzaldehyde, glacial acetic acid and anhydrous ethanol in step a1 is 10 mmol: 30 mmol: 1-2 mL: 50-60 mL.

[0007] In a preferred embodiment of the present invention, the mass fraction of the ethanol solution in step a1 is 40-50%.

[0008] In a preferred embodiment of the present invention, the ratio of the polycyanoSchiff base compound, DOPO and anhydrous ethanol in step a2 is 10 mmol: 30 mmol: 70-80 mL.

[0009] In a preferred embodiment of the present invention, the heat resistance enhancing agent is prepared by the following steps: Step b1: Add tetraphenylmethane and fuming nitric acid to a three-necked flask equipped with a stirrer, thermometer, constant pressure dropping funnel and gas delivery tube. Purge with nitrogen for protection and stir at -20℃ and 200-300 r / min for 40-60 min. Then, while stirring, add acetic anhydride solution dropwise at a rate of 1-3 drops / s. After the addition is complete, continue stirring for 1-2 h. Then, raise the temperature to 20-30℃ and continue stirring for 3-5 h. After the reaction is complete, filter the reaction product under vacuum. Wash the filter cake 2-3 times with anhydrous ethanol and then recrystallize with N,N-dimethylformamide to obtain the polynitro compound. Step b2: Add the polynitro compound, palladium on carbon, and tetrahydrofuran to the reactor, purge the air in the reactor with nitrogen, and then purge with hydrogen to maintain the pressure in the reactor at 1.8-2.2 MPa. Then stir the reaction at a temperature of 30-40℃ and a stirring rate of 200-300 r / min for 20-25 h. After the reaction is completed, filter the reaction product under vacuum, and remove the solvent by rotary evaporation of the filtrate to obtain the polyamine compound. Step b3: Add N,N'-(4,4'-methylenediphenyl)bismaleimide, polyamino compound and acetone to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir the reaction at 20-25℃ and 200-300 r / min for 10-20 min. Then raise the temperature to 60-70℃ and continue stirring for 8-10 h. Then add bisphenol A diglycidyl ether and continue stirring for 20-40 min. After the reaction is completed, cool the reaction product to room temperature and then remove the solvent by rotary evaporation to obtain the heat resistance enhancer.

[0010] In a preferred embodiment of the present invention, the ratio of tetraphenylmethane, fuming nitric acid and acetic anhydride solution used in step b1 is 20 mmol: 40-45 mL: 80-90 mL.

[0011] In a preferred embodiment of the present invention, the acetic anhydride solution in step b1 is a mixture of acetic anhydride and acetic acid in a volume ratio of 1-1.5:5.

[0012] In a preferred embodiment of the present invention, the ratio of the polynitro compound, palladium on carbon, and tetrahydrofuran in step b2 is 5g:0.3-0.5g:70-80mL.

[0013] In a preferred embodiment of the present invention, the palladium on carbon in step b2 is palladium on carbon with a palladium loading of 10% by mass.

[0014] In a preferred embodiment of the present invention, the ratio of N,N'-(4,4'-methylenediphenyl)bismaleimide, polyamino compound, acetone and bisphenol A diglycidyl ether in step b3 is 20 mmol: 10 mmol: 130-150 mL: 10-12 mmol.

[0015] As a preferred embodiment of the present invention, a processing method for an automotive fast charging cable includes the following steps: Step 1: Weigh out 20-25 parts LLDPE plastic, 16-18 parts EVA plastic, 10-12 parts POE plastic, 1-7 parts DOPO polycyanate compound, 8-12 parts heat resistance reinforcing agent, 0.5-0.7 parts antioxidant, and 1.1-1.5 parts polyethylene wax according to the following weight proportions, and set aside. Step 2: Mix LLDPE plastic, EVA plastic, POE plastic, polycyano DOPO compound, heat resistance enhancer, antioxidant and polyethylene wax evenly, and then melt extrude it onto the surface of copper core wire to form a temperature-resistant and flame-retardant sheath, thus obtaining the automotive fast charging cable.

[0016] In a preferred embodiment of the present invention, the LLDPE plastic is LLDPE M2720A.

[0017] In a preferred embodiment of the present invention, the EVA plastic is EVA FL00328.

[0018] In a preferred embodiment of the present invention, the POE plastic is POE C0570D.

[0019] In a preferred embodiment of the present invention, the antioxidant is antioxidant 1010.

[0020] In a preferred embodiment of the present invention, the polyethylene wax is YY-613A.

[0021] The beneficial effects of this invention are: This invention discloses a fast-charging cable for automobiles and its processing technology. The process involves uniformly mixing LLDPE plastic, EVA plastic, POE plastic, polycyano-DOPO-based compound, heat-resistant reinforcing agent, antioxidant, and polyethylene wax, then melt-extruding the mixture onto the surface of a copper core wire to form a temperature-resistant and flame-retardant sheath, thus obtaining the fast-charging cable. This processing technology, by adding polycyano-DOPO-based compound and heat-resistant reinforcing agent as core additives to the cable sheath material, achieves a synergistic effect, significantly improving the heat resistance and flame-retardant properties of the cable sheath material. This ensures the stability and safety of the cable sheath material under extreme environments, thereby enhancing the service life and safety of the fast-charging cable, demonstrating high practical value and market potential.

[0022] In the process of preparing automotive fast charging cables, a polycyano-DOPO-based compound was first prepared. This was achieved through a reaction between melamine and 4-cyanobenzaldehyde, where the amino group on melamine reacts with the aldehyde group on 4-cyanobenzaldehyde to form a Schiff base structure. Simultaneously, a cyano group was introduced, yielding a polycyano-Schiff base compound. Then, through a reaction between the polycyano-Schiff base compound and DOPO, the Schiff base structure on the polycyano-Schiff base compound underwent an addition reaction with the pH group on DOPO, introducing the DOPO structure and obtaining the polycyano-DOPO-based compound. The molecular structure of this polycyano-DOPO-based compound contains multiple organophosphorus and organonitrogen compounds. Under their synergistic effect, these compounds promote the formation of a dense char layer during combustion and release non-combustible gases, achieving the effect of isolating oxygen and heat, thus effectively exerting a flame-retardant effect.

[0023] In the process of preparing automotive fast charging cables, a heat-resistant reinforcing agent was also prepared. Tetraphenylmethane was used as a raw material and nitrated to introduce nitro groups onto its benzene ring, yielding a polynitro compound. Hydrogen was then used to reduce the nitro groups on the polynitro compound to amino groups, resulting in a polyamino compound. The alkenyl groups on N,N'-(4,4'-methylenediphenyl)bismaleimide underwent a Michael addition reaction with the amino groups on the polyamino compound, leading to polymerization. Furthermore, the epoxy groups on bisphenol A diglycidyl ether reacted with the imino groups to achieve crosslinking, yielding the heat-resistant reinforcing agent. This heat-resistant reinforcing agent contains numerous cyclic structures and has a high degree of crosslinking, significantly improving the high-temperature resistance of the cable sheath material and enhancing the safety of automotive fast charging cables. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: This embodiment describes a processing technology for a fast charging cable for automobiles, including the following steps: Step S1: 10 mmol of melamine, 30 mmol of 4-cyanobenzaldehyde, 1 mL of glacial acetic acid and 50 mL of anhydrous ethanol were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 20 °C and 200 r / min for 20 min. Then the temperature was raised to 80 °C and the mixture was stirred for 8 h. After the reaction was completed, the reaction product was cooled to room temperature. The solvent was then removed by rotary evaporation. The product was washed twice with a 40% ethanol solution and then placed in a vacuum drying oven and dried at 70 °C for 3 h to obtain a polycyanoSchiff base compound. Step S2: 10 mmol of polycyano Schiff base compound, 30 mmol of DOPO and 70 mL of anhydrous ethanol were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 20 °C and 200 r / min for 10 min. Then the temperature was raised to 80 °C and the mixture was stirred for 10 h. After the reaction was completed, the reaction product was cooled to room temperature and then vacuum filtered. The filter cake was washed twice with distilled water and then placed in a vacuum drying oven and dried at 70 °C for 6 h to obtain polycyano DOPO-based compound. Step S3: Add 20 mmol of tetraphenylmethane and 40 mL of fuming nitric acid to a three-necked flask equipped with a stirrer, thermometer, constant pressure dropping funnel and gas delivery tube. Purge with nitrogen for protection and stir at -20℃ and 200 r / min for 40 min. Then, while stirring, add 80 mL of acetic anhydride solution (1:5 volume ratio of acetic anhydride and acetic acid) dropwise at a rate of 1 drop / s. After the addition is complete, continue stirring for 1 h. Then, raise the temperature to 20℃ and continue stirring for 3 h. After the reaction is complete, filter the reaction product under vacuum. Wash the filter cake twice with anhydrous ethanol and then recrystallize with N,N-dimethylformamide to obtain the polynitro compound. Step S4: Add 5g of polynitro compound, 0.3g of palladium on carbon with a palladium loading of 10% by mass and 70mL of tetrahydrofuran to the reactor. Purge the air in the reactor with nitrogen gas to replace it, and then purge with hydrogen gas to maintain the pressure in the reactor at 1.8MPa. Then stir and react for 20h at a temperature of 30℃ and a stirring rate of 200r / min. After the reaction is completed, filter the reaction product under vacuum, and remove the solvent by rotary evaporation of the filtrate to obtain the polyamine compound. Step S5: 20 mmol N,N'-(4,4'-methylenediphenyl)bismaleimide, 10 mmol polyamino compound and 130 mL acetone were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The reaction was stirred at 20 °C and 200 r / min for 10 min. Then the temperature was raised to 60 °C and the reaction was stirred for 8 h. Then 10 mmol bisphenol A diglycidyl ether was added and the reaction was stirred for 20 min. After the reaction was completed, the reaction product was cooled to room temperature and the solvent was removed by rotary evaporation to obtain the heat resistance enhancer. Step S6: Weigh out 20 parts by weight of LLDPE plastic, 16 parts by weight of EVA plastic, 10 parts by weight of POE plastic, 1 part by weight of polycyanoDOPO compound, 8 parts by weight of heat-resistant reinforcing agent, 0.5 parts by weight of antioxidant, and 1.1 parts by weight of polyethylene wax, and set aside; the LLDPE plastic is LLDPE M2720A; the EVA plastic is EVA FL00328; the POE plastic is POE C0570D; the antioxidant is antioxidant 1010; and the polyethylene wax is YY-613A; Step S7: Mix LLDPE plastic, EVA plastic, POE plastic, polycyano DOPO compound, heat resistance enhancer, antioxidant and polyethylene wax evenly, and then melt extrude it onto the surface of copper core wire to form a temperature-resistant and flame-retardant sheath, thus obtaining a fast charging cable for automobiles.

[0026] Example 2: This embodiment describes a processing technology for a fast charging cable for automobiles, including the following steps: Step S1: 10 mmol of melamine, 30 mmol of 4-cyanobenzaldehyde, 1.5 mL of glacial acetic acid and 55 mL of anhydrous ethanol were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 22 °C and 250 r / min for 25 min. Then the temperature was raised to 85 °C and the mixture was stirred for 9 h. After the reaction was completed, the reaction product was cooled to room temperature. The solvent was then removed by rotary evaporation. The product was washed twice with a 45% ethanol solution and then placed in a vacuum drying oven and dried at 75 °C for 4 h to obtain a polycyanoSchiff base compound. Step S2: 10 mmol of polycyano-Schiff base compound, 30 mmol of DOPO and 75 mL of anhydrous ethanol were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 22 °C and 250 r / min for 15 min. Then the temperature was raised to 85 °C and the mixture was stirred for 12 h. After the reaction was completed, the reaction product was cooled to room temperature and then vacuum filtered. The filter cake was washed twice with distilled water and then placed in a vacuum drying oven and dried at 75 °C for 7 h to obtain polycyano-DOPO-based compound. Step S3: Add 20 mmol of tetraphenylmethane and 42 mL of fuming nitric acid to a three-necked flask equipped with a stirrer, thermometer, constant pressure dropping funnel and gas delivery tube. Purge with nitrogen for protection and stir at -20℃ and 250 r / min for 50 min. Then, while stirring, add 85 mL of acetic anhydride solution (1.2:5 volume ratio of acetic anhydride and acetic acid) dropwise at a rate of 2 drops / s. After the addition is complete, continue stirring for 1.5 h. Then, raise the temperature to 25℃ and continue stirring for 4 h. After the reaction is complete, filter the reaction product under vacuum. Wash the filter cake twice with anhydrous ethanol and then recrystallize with N,N-dimethylformamide to obtain the polynitro compound. Step S4: Add 5g of polynitro compound, 0.4g of palladium on carbon with a palladium loading of 10% and 75mL of tetrahydrofuran to the reactor. Purge the air in the reactor with nitrogen, then purge with hydrogen to maintain the pressure in the reactor at 2MPa. Stir and react for 22h at a temperature of 35℃ and a stirring rate of 250r / min. After the reaction is completed, filter the reaction product under vacuum, and remove the solvent by rotary evaporation of the filtrate to obtain the polyamine compound. Step S5: 20 mmol N,N'-(4,4'-methylenediphenyl)bismaleimide, 10 mmol polyamino compound and 140 mL acetone were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The reaction was stirred at 22 °C and 250 r / min for 15 min. Then the temperature was raised to 65 °C and the reaction was stirred for 9 h. Then 11 mmol bisphenol A diglycidyl ether was added and the reaction was stirred for 30 min. After the reaction was completed, the reaction product was cooled to room temperature and the solvent was removed by rotary evaporation to obtain the heat resistance enhancer. Step S6: Weigh out 22 parts by weight of LLDPE plastic, 17 parts by weight of EVA plastic, 11 parts by weight of POE plastic, 4 parts by weight of polycyanoDOPO compound, 10 parts by weight of heat-resistant reinforcing agent, 0.6 parts by weight of antioxidant, and 1.3 parts by weight of polyethylene wax, and set aside; the LLDPE plastic is LLDPE M2720A; the EVA plastic is EVA FL00328; the POE plastic is POE C0570D; the antioxidant is antioxidant 1010; and the polyethylene wax is YY-613A; Step S7: Mix LLDPE plastic, EVA plastic, POE plastic, polycyano DOPO compound, heat resistance enhancer, antioxidant and polyethylene wax evenly, and then melt extrude it onto the surface of copper core wire to form a temperature-resistant and flame-retardant sheath, thus obtaining a fast charging cable for automobiles.

[0027] Example 3: This embodiment describes a processing technology for a fast charging cable for automobiles, including the following steps: Step S1: 10 mmol of melamine, 30 mmol of 4-cyanobenzaldehyde, 2 mL of glacial acetic acid and 60 mL of anhydrous ethanol were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 30 min. Then the temperature was raised to 90 °C and the mixture was stirred for 10 h. After the reaction was completed, the reaction product was cooled to room temperature. The solvent was then removed by rotary evaporation. The product was washed three times with a 50% ethanol solution. The product was then placed in a vacuum drying oven and dried at 80 °C for 5 h to obtain a polycyanoSchiff base compound. Step S2: 10 mmol of polycyano-Schiff base compound, 30 mmol of DOPO and 80 mL of anhydrous ethanol were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 20 min. Then the temperature was raised to 90 °C and the mixture was stirred for 15 h. After the reaction was completed, the reaction product was cooled to room temperature and then vacuum filtered. The filter cake was washed three times with distilled water and then placed in a vacuum drying oven and dried at 80 °C for 8 h to obtain polycyano-DOPO-based compound. Step S3: Add 20 mmol of tetraphenylmethane and 45 mL of fuming nitric acid to a three-necked flask equipped with a stirrer, thermometer, constant pressure dropping funnel and gas delivery tube. Purge with nitrogen for protection and stir at -20℃ and 300 r / min for 60 min. Then, while stirring, add 90 mL of acetic anhydride solution (1.5:5 volume ratio of acetic anhydride and acetic acid) dropwise at a rate of 3 drops / s. After the addition is complete, continue stirring for 2 h. Then, raise the temperature to 30℃ and continue stirring for 5 h. After the reaction is complete, filter the reaction product under vacuum. Wash the filter cake three times with anhydrous ethanol and recrystallize with N,N-dimethylformamide to obtain the polynitro compound. Step S4: Add 5g of polynitro compound, 0.5g of palladium on carbon with a palladium loading of 10% and 80mL of tetrahydrofuran to the reactor. Purge the air in the reactor with nitrogen, and then purge with hydrogen to maintain the pressure in the reactor at 2.2MPa. Then stir and react for 25h at a temperature of 40℃ and a stirring rate of 300r / min. After the reaction is completed, filter the reaction product under vacuum, and remove the solvent by rotary evaporation of the filtrate to obtain the polyamine compound. Step S5: 20 mmol N,N'-(4,4'-methylenediphenyl)bismaleimide, 10 mmol polyamino compound and 150 mL acetone were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The reaction was stirred at 25 °C and 300 r / min for 20 min. Then the temperature was raised to 70 °C and the reaction was stirred for 10 h. Then 12 mmol bisphenol A diglycidyl ether was added and the reaction was stirred for 40 min. After the reaction was completed, the reaction product was cooled to room temperature and the solvent was removed by rotary evaporation to obtain the heat resistance enhancer. Step S6: Weigh out 25 parts by weight of LLDPE plastic, 18 parts by weight of EVA plastic, 12 parts by weight of POE plastic, 7 parts by weight of polycyanoDOPO compound, 12 parts by weight of heat-resistant reinforcing agent, 0.7 parts by weight of antioxidant, and 1.5 parts by weight of polyethylene wax, and set aside; the LLDPE plastic is LLDPE M2720A; the EVA plastic is EVA FL00328; the POE plastic is POE C0570D; the antioxidant is antioxidant 1010; and the polyethylene wax is YY-613A; Step S7: Mix LLDPE plastic, EVA plastic, POE plastic, polycyano DOPO compound, heat resistance enhancer, antioxidant and polyethylene wax evenly, and then melt extrude it onto the surface of copper core wire to form a temperature-resistant and flame-retardant sheath, thus obtaining a fast charging cable for automobiles.

[0028] Comparative Example 1: This comparative example illustrates the processing technology of a fast charging cable for automobiles, including the following steps: Step S1: Weigh out 25 parts by weight of LLDPE plastic, 18 parts by weight of EVA plastic, 12 parts by weight of POE plastic, 0.7 parts by weight of antioxidant, and 1.5 parts by weight of polyethylene wax, and set aside; the LLDPE plastic is LLDPE M2720A; the EVA plastic is EVAFL00328; the POE plastic is POE C0570D; the antioxidant is antioxidant 1010; and the polyethylene wax is YY-613A; Step S2: Mix LLDPE plastic, EVA plastic, POE plastic, antioxidant and polyethylene wax evenly, and then melt-extrude it onto the surface of the copper core wire to form a temperature-resistant and flame-retardant sheath, thus obtaining the automotive fast charging cable.

[0029] Comparative Example 2: This comparative example illustrates the processing technology of a fast charging cable for automobiles, including the following steps: Step S1: Add 20 mmol of tetraphenylmethane and 45 mL of fuming nitric acid to a three-necked flask equipped with a stirrer, thermometer, constant pressure dropping funnel and gas delivery tube. Purge with nitrogen for protection and stir at -20℃ and 300 r / min for 60 min. Then, while stirring, add 90 mL of acetic anhydride solution (a mixture of acetic anhydride and acetic acid in a volume ratio of 1.5:5) dropwise at a rate of 3 drops / s. After the addition is complete, continue stirring for 2 h. Then, raise the temperature to 30℃ and continue stirring for 5 h. After the reaction is complete, filter the reaction product under vacuum. Wash the filter cake three times with anhydrous ethanol and then recrystallize with N,N-dimethylformamide to obtain the polynitro compound. Step S2: Add 5g of polynitro compound, 0.5g of palladium on carbon with a palladium loading of 10% and 80mL of tetrahydrofuran to the reactor. Purge the air in the reactor with nitrogen, and then purge with hydrogen to maintain the pressure in the reactor at 2.2MPa. Then stir and react for 25h at a temperature of 40℃ and a stirring rate of 300r / min. After the reaction is completed, filter the reaction product under vacuum, and remove the solvent by rotary evaporation of the filtrate to obtain the polyamine compound. Step S3: 20 mmol N,N'-(4,4'-methylenediphenyl)bismaleimide, 10 mmol polyamino compound and 150 mL acetone were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The reaction was stirred at 25 °C and 300 r / min for 20 min. Then the temperature was raised to 70 °C and the reaction was stirred for 10 h. Then 12 mmol bisphenol A diglycidyl ether was added and the reaction was stirred for 40 min. After the reaction was completed, the reaction product was cooled to room temperature and the solvent was removed by rotary evaporation to obtain the heat resistance enhancer. Step S4: Weigh out 25 parts by weight of LLDPE plastic, 18 parts by weight of EVA plastic, 12 parts by weight of POE plastic, 12 parts by weight of heat-resistant reinforcing agent, 0.7 parts by weight of antioxidant, and 1.5 parts by weight of polyethylene wax, and set aside; the LLDPE plastic is LLDPE M2720A; the EVA plastic is EVA FL00328; the POE plastic is POE C0570D; the antioxidant is antioxidant 1010; and the polyethylene wax is YY-613A; Step S5: Mix LLDPE plastic, EVA plastic, POE plastic, heat-resistant reinforcing agent, antioxidant and polyethylene wax evenly, and then melt-extrude it onto the surface of copper core wire to form a temperature-resistant and flame-retardant sheath, thus obtaining an automotive fast charging cable.

[0030] Comparative Example 3: This comparative example illustrates the processing technology of a fast charging cable for automobiles, including the following steps: Step S1: 10 mmol of melamine, 30 mmol of 4-cyanobenzaldehyde, 2 mL of glacial acetic acid and 60 mL of anhydrous ethanol were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 30 min. Then the temperature was raised to 90 °C and the mixture was stirred for 10 h. After the reaction was completed, the reaction product was cooled to room temperature. The solvent was then removed by rotary evaporation. The product was washed three times with a 50% ethanol solution. The product was then placed in a vacuum drying oven and dried at 80 °C for 5 h to obtain a polycyanoSchiff base compound. Step S2: 10 mmol of polycyano-Schiff base compound, 30 mmol of DOPO and 80 mL of anhydrous ethanol were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 20 min. Then the temperature was raised to 90 °C and the mixture was stirred for 15 h. After the reaction was completed, the reaction product was cooled to room temperature and then vacuum filtered. The filter cake was washed three times with distilled water and then placed in a vacuum drying oven and dried at 80 °C for 8 h to obtain polycyano-DOPO-based compound. Step S3: Weigh out 25 parts by weight of LLDPE plastic, 18 parts by weight of EVA plastic, 12 parts by weight of POE plastic, 7 parts by weight of polycyanoDOPO compound, 0.7 parts by weight of antioxidant, and 1.5 parts by weight of polyethylene wax, and set aside; the LLDPE plastic is LLDPE M2720A; the EVA plastic is EVA FL00328; the POE plastic is POE C0570D; the antioxidant is antioxidant 1010; and the polyethylene wax is YY-613A; Step S4: Mix LLDPE plastic, EVA plastic, POE plastic, polycyano DOPO compound, antioxidant and polyethylene wax evenly, and then melt-extrude it onto the surface of copper core wire to form a temperature-resistant and flame-retardant sheath, thus obtaining a fast charging cable for automobiles.

[0031] The temperature-resistant and flame-retardant sheaths of the automotive fast-charging cables of Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests. Under the conditions of nitrogen atmosphere, heating rate of 10℃ / min, and temperature range of 25-800℃, the temperature at which the weight loss was 5% was measured using a thermogravimetric analyzer. The limiting oxygen index was tested according to GB / T 2406.2-2009, and the UL94 rating was tested according to GB / T 2408-2008.

[0032] The test results are shown in the table below:

[0033] Referring to the data in the table above, and based on the comparison between Examples 1-3 and Comparative Examples 1-3, it can be seen that adding heat-resistant reinforcing agents and polycyano-DOPO compounds can significantly improve the heat resistance stability and flame retardant performance of the temperature-resistant and flame-retardant sheath, resulting in excellent temperature resistance and flame retardant performance of the final automotive fast-charging cable.

[0034] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.

Claims

1. A fast charging cable for automobiles, characterized in that, Including the copper core wire and the temperature-resistant and flame-retardant sheath on the surface of the copper core wire; The temperature-resistant and flame-retardant sheath comprises the following components in parts by weight: 20-25 parts LLDPE plastic, 16-18 parts EVA plastic, 10-12 parts POE plastic, 1-7 parts polycyanoDOPO compound, 8-12 parts heat-resistant reinforcing agent, 0.5-0.7 parts antioxidant, and 1.1-1.5 parts polyethylene wax; The polycyanoDOPO-based compound is prepared by the following steps: Step a1: Melamine, 4-cyanobenzaldehyde, glacial acetic acid and anhydrous ethanol were stirred and reacted. After the reaction was completed, the reaction product was cooled, then rotary evaporated, washed and dried to obtain polycyanoSchiff base compound. Step a2: The polycyano Schiff base compound, DOPO and anhydrous ethanol are stirred and reacted. After the reaction is completed, the reaction product is cooled and then vacuum filtered. The filter cake is washed and dried to obtain the polycyano DOPO-based compound.

2. The fast charging cable for automobiles according to claim 1, characterized in that, The ratio of melamine, 4-cyanobenzaldehyde, glacial acetic acid and anhydrous ethanol used in step a1 is 10 mmol: 30 mmol: 1-2 mL: 50-60 mL.

3. The fast charging cable for automobiles according to claim 1, characterized in that, The ratio of the polycyanoSchiff base compound, DOPO, and anhydrous ethanol used in step a2 is 10 mmol: 30 mmol: 70-80 mL.

4. The fast charging cable for automobiles according to claim 1, characterized in that, The heat resistance enhancer is prepared by the following steps: Step b1: Tetraphenylmethane and fuming nitric acid are stirred and reacted, then acetic anhydride solution is added dropwise. After the addition is complete, the reaction is stirred and reacted. After the reaction is completed, the reaction product is filtered under vacuum, the filter cake is washed and recrystallized to obtain polynitro compounds. Step b2: The polynitro compound, palladium on carbon, and tetrahydrofuran are stirred and reacted under a hydrogen atmosphere. After the reaction is completed, the reaction product is filtered under vacuum and the filtrate is evaporated by rotary evaporation to obtain the polyamine compound. Step b3: N,N'-(4,4'-methylenediphenyl)bismaleimide, polyamino compound and acetone are stirred and reacted, then bisphenol A diglycidyl ether is added and the reaction is continued with stirring. After the reaction is completed, the reaction product is cooled and then rotary evaporated to obtain the heat resistance enhancer.

5. The fast charging cable for automobiles according to claim 4, characterized in that, In step b1, the ratio of tetraphenylmethane, fuming nitric acid, and acetic anhydride solution is 20 mmol: 40-45 mL: 80-90 mL; the acetic anhydride solution is a mixture of acetic anhydride and acetic acid in a volume ratio of 1-1.5:

5.

6. The fast charging cable for automobiles according to claim 4, characterized in that, In step b2, the ratio of the polynitro compound, palladium on carbon, and tetrahydrofuran is 5g:0.3-0.5g:70-80mL; the palladium on carbon is palladium on carbon with a palladium loading of 10% by mass.

7. The fast charging cable for automobiles according to claim 4, characterized in that, The ratio of N,N'-(4,4'-methylenediphenyl)bismaleimide, polyamino compound, acetone and bisphenol A diglycidyl ether in step b3 is 20 mmol: 10 mmol: 130-150 mL: 10-12 mmol.

8. A processing method for an automotive fast-charging cable as described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Weigh out 20-25 parts LLDPE plastic, 16-18 parts EVA plastic, 10-12 parts POE plastic, 1-7 parts DOPO polycyanate compound, 8-12 parts heat resistance reinforcing agent, 0.5-0.7 parts antioxidant, and 1.1-1.5 parts polyethylene wax according to the following weight proportions, and set aside. Step 2: Mix LLDPE plastic, EVA plastic, POE plastic, polycyano DOPO compound, heat resistance enhancer, antioxidant and polyethylene wax evenly, and then melt extrude it onto the surface of copper core wire to form a temperature-resistant and flame-retardant sheath, thus obtaining the automotive fast charging cable.

9. The processing technology of a fast charging cable for automobiles according to claim 8, characterized in that, The LLDPE plastic is LLDPE M2720A; The EVA plastic is EVA FL00328; The POE plastic is POE C0570D; The antioxidant is antioxidant 1010; The polyethylene wax is YY-613A.

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