A new energy vehicle connects power supply with halogen-free low smoke high flame retardant cable

Abstract

This invention discloses a halogen-free, low-smoke, and highly flame-retardant cable for power connection in new energy vehicles, belonging to the technical field of flame-retardant cable materials. It addresses the technical problem that the flame-retardant, low-smoke performance, and mechanical strength of existing power connection cables for new energy vehicles need further improvement. Specifically, it includes a conductor and an insulating sheath layer disposed around the conductor. By weight, the insulating sheath layer comprises: 50-60 parts of ethylene-vinyl acetate copolymer, 35-45 parts of ethylene-butyl acrylate copolymer, 26-32 parts of molybdenum-coated magnesium filler, and 18-22 parts of epoxidized polyolefin. This invention, through the preparation of a copolymer matrix composed of molybdenum-coated magnesium filler and epoxidized polyolefin on ethylene-vinyl acetate copolymer and ethylene-butyl acrylate, not only effectively improves the insulation performance, flame-retardant performance, and mechanical strength of the cable material, but also effectively reduces the amount of smoke during combustion.

Description

Technical Field

[0001] This invention relates to the field of flame-retardant cable materials technology, specifically to a halogen-free, low-smoke, high flame-retardant cable for connecting power supplies in new energy vehicles. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the degree of electrification of vehicles is constantly improving. As an important component for power transmission between power batteries, drive motors, electronic control systems and auxiliary electrical equipment, the performance of power cables directly affects the safety, stability and service life of the entire vehicle.

[0003] Compared with traditional electrical wires and cables used in fuel vehicles, cables used for power connection in new energy vehicles typically need to withstand high voltage, current, and complex operating conditions such as frequent bending, vibration, and thermal shock over long periods of time. They must also meet requirements for lightweight, miniaturization, heat resistance, flame retardancy, low smoke, and high insulation. Therefore, higher standards are required for cable insulation sheath materials.

[0004] Currently, the insulation and sheathing layers of power cables used in new energy vehicles are mostly made of polyolefin, ethylene-vinyl acetate copolymer, or rubber polymer materials. Flame retardants are added to improve the fire safety performance of the materials. Although traditional halogenated flame retardant systems have good flame retardant effects, they easily release a large amount of smoke and corrosive and toxic gases during combustion, which not only causes secondary damage to the vehicle's electrical system, but also affects escape and rescue in a fire environment.

[0005] However, conventional halogen-free low-smoke flame-retardant cable materials typically employ inorganic or intumescent flame-retardant systems such as magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate, and borates. While these flame-retardant systems can reduce the release of combustion heat and the generation of harmful gases to some extent, under high-filling conditions, the interfacial compatibility between inorganic particles and organic resins is poor, making agglomeration easy. This leads to a decrease in the tensile strength, elongation at break, and flexibility of the material, making it difficult to meet the reliability requirements of new energy vehicle cables for repeated bending and long-term service. At the same time, the large-scale introduction of flame-retardant components may also adversely affect the volume resistivity, electrical insulation stability, and damp heat resistance of the material, thereby affecting the safe use of the cable under complex working conditions.

[0006] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a halogen-free, low-smoke, and highly flame-retardant cable for connecting power supplies to new energy vehicles, thereby addressing the technical problem that the flame-retardant, low-smoke performance, and mechanical strength of existing power supply cables for new energy vehicles need further improvement.

[0008] The objective of this invention can be achieved through the following technical solution: A halogen-free, low-smoke, high-flame-retardant cable for connecting power supplies to new energy vehicles, comprising a conductor and an insulating sheath layer disposed on the outer periphery of the conductor, wherein, by weight, the insulating sheath layer comprises: 50-60 parts of ethylene-vinyl acetate copolymer, 35-45 parts of ethylene-butyl acrylate copolymer, 26-32 parts of molybdenum-coated magnesium filler, 18-22 parts of epoxidized polyolefin, 0.7-0.9 parts of antioxidant, and 0.6-0.8 parts of lubricant.

[0009] Furthermore, the preparation method of molybdenum-coated magnesium filler is as follows: under the protection of an inert gas atmosphere, ammonia-terminated hydrogen-containing siloxane and toluene are mixed and stirred until the system is dissolved. Epoxy-modified molybdenum-coated magnesium particles are added to the reaction system. The reaction system is heated to 80-90℃ and kept at this temperature for 60-80 min. 3-Butene-1-amine and platinum catalyst are added to the reaction system and kept at this temperature for 4-6 h. After post-treatment, molybdenum-coated magnesium filler is obtained.

[0010] Furthermore, the ratio of the ammonia-terminated hydrogen-containing siloxane, toluene, epoxy-modified molybdenum-coated magnesium particles, 3-butene-1-amine, and platinum catalyst is 10-12g:100mL:15-17g:3-5g:0.2g, and the platinum catalyst is chloroplatinic acid. The post-treatment includes: after the reaction is complete, the reaction system is subjected to negative pressure to remove low-boiling substances by vacuum evaporation, the reaction system is cooled to room temperature, anhydrous ethanol is added to the reaction system, the mixture is stirred and dispersed for 30-50 minutes, filtered, the filter cake is washed three times with anhydrous ethanol and then dried, and the filter cake is transferred to a drying oven at a temperature of 60-70℃ and dried to constant weight to obtain molybdenum-coated magnesium packing.

[0011] Furthermore, the preparation method of ammonia-terminated hydrogen-containing siloxane is as follows: D4H, D4 and catalyst are mixed and stirred, the reaction system is heated to 85-95℃ and kept at this temperature for 80-100 min, 1,3-bis(aminopropyl)tetramethyldisiloxane is added to the reaction system, and the reaction is kept at this temperature for 3-5 h. After post-treatment, ammonia-terminated hydrogen-containing siloxane is obtained.

[0012] Furthermore, the ratio of D4H, D4, catalyst, and 1,3-bis(aminopropyl)tetramethyldisiloxane is 3-4g:10-15g:2-3mL:1.1-1.5g, the catalyst is an 8-10M sodium hydroxide aqueous solution, and the post-treatment includes: after the reaction is complete, the reaction system is cooled to room temperature, toluene and purified water are added to the reaction system, stirred and dispersed for 20-30min, allowed to stand and separated, the organic phase is washed 3 times with purified water and then transferred to a rotary evaporator with a water bath temperature of 85-95℃, and low-boiling substances are removed by vacuum evaporation to obtain ammonia-terminated hydrogen-containing siloxane.

[0013] Furthermore, epoxy-modified molybdenum-coated magnesium particles are obtained through the following steps:

[0014] A1. Mix nano-magnesium hydroxide, deionized water, sodium molybdate and sodium dodecyl sulfate, ultrasonically disperse for 50-60 min, add calcium chloride solution to the reaction system, heat the reaction system to 85-95℃, keep it at the temperature for 4-5 h, and then perform post-treatment to obtain molybdenum-coated magnesium particles.

[0015] A2. Mix and stir molybdenum-coated magnesium particles, anhydrous ethanol, and KH-560. Heat the reaction system to 50-60℃, add sodium hydroxide aqueous solution to the reaction system, keep the reaction at this temperature for 60-80 minutes, and then perform post-treatment to obtain epoxy-modified molybdenum-coated magnesium particles.

[0016] Further, in step A1, the ratio of the amount of nano-magnesium hydroxide, deionized water, sodium molybdate, sodium dodecyl sulfate, and calcium chloride solution is 5g:50mL:3-4g:0.2-0.3g:10mL. The calcium chloride solution is composed of calcium chloride and purified water at a ratio of 1g:3mL. The post-treatment includes: after the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed three times with purified water, and then transferred to a drying oven at a temperature of 110-120℃ for drying for 10-12 hours to obtain molybdenum-coated magnesium particles.

[0017] Further, in step A2, the ratio of the molybdenum-coated magnesium particles, anhydrous ethanol, KH-560, and sodium hydroxide aqueous solution is 5g:30mL:1-2g:6mL, and the concentration of the sodium hydroxide aqueous solution is 3-5M. The post-treatment includes: after the reaction is complete, the reaction system is cooled to room temperature, filtered, the filter cake is washed with purified water until neutral, dried, and the filter cake is transferred to a drying oven at a temperature of 70-80℃ and dried to constant weight to obtain epoxy-modified molybdenum-coated magnesium particles.

[0018] Furthermore, epoxidized polyolefins are obtained by the following steps:

[0019] B1. Mix and stir ammonium polyphosphate, zinc borate, KH-570 and anhydrous ethanol. Heat the reaction system to 40-50℃, add sodium hydroxide aqueous solution to the reaction system, keep the reaction at the temperature for 80-100 min, and then perform post-treatment to obtain activated mixed particles.

[0020] B2. Mix butyl acrylate, vinyl acetate, dibutyl maleate, 1,2-epoxy-5-hexene, activated mixed particles, and toluene, and stir. Heat the reaction system to 70-80℃, add initiator solution dropwise to the reaction system, keep the reaction at this temperature for 4-6 hours, and then perform post-treatment to obtain epoxidized polyolefin.

[0021] Further, in step B1, the ratio of ammonium polyphosphate, zinc borate, KH-570, anhydrous ethanol, and sodium hydroxide aqueous solution is 5g:2-3g:1.3-1.6g:50mL:3-5mL, and the concentration of the sodium hydroxide aqueous solution is 1-2M. The post-treatment includes: after the reaction is complete, the reaction system is cooled to room temperature, filtered, the filter cake is washed three times with anhydrous ethanol and then dried, the filter cake is transferred to a drying oven at 70-80℃ and dried to constant weight to obtain activated mixed particles.

[0022] Further, in step B2, the ratio of butyl acrylate, vinyl acetate, dibutyl maleate, 1,2-epoxy-5-hexene, activated mixed particles, toluene, and initiator solution is 7-8g:5-6g:2-3g:3-4g:5-6g:100mL:10mL. The initiator solution is composed of azobisisobutyronitrile and toluene at a ratio of 1g:20mL. The post-treatment includes: after the reaction is complete, the reaction system is heated to 90°C, and low-boiling substances are removed by vacuum distillation to obtain epoxidized polyolefin.

[0023] The present invention has the following beneficial effects:

[0024] 1. This invention constructs molybdenum-coated magnesium particles with nano-magnesium hydroxide as the core and sodium molybdate as the molybdenum source shell. During heating, magnesium hydroxide can absorb heat and decompose to release water of crystallization, thereby reducing the temperature of the material's combustion zone and diluting flammable pyrolysis products. The molybdenum source coating layer helps to promote the formation of a more stable and denser carbonization protective layer during combustion, enhancing the barrier effect of the condensed phase and inhibiting further heat and flammable gas transfer. After modification with KH-560 and ammonia-terminated hydrogen-containing siloxane, an interface layer with both organic phase affinity and reactivity is formed on the filler surface. This not only improves the dispersibility of the filler in the resin matrix but also reduces the hygroscopicity and interface defects caused by the exposed surface of inorganic particles, improving the oxygen index and volume resistivity of the material while inhibiting smoke generation.

[0025] 2. This invention also selects ammonium polyphosphate and zinc borate as raw materials, which are activated by KH-570 to form activated mixed particles modified with unsaturated olefin double bonds on their surface. The activated mixed particles further participate in the construction of the epoxidized polyolefin system, so that the resulting epoxidized polyolefin not only has high polarity and good compatibilization ability, but also has the dual functions of flame retardant component carrying and interface regulation. The synthesized epoxidized polyolefin has good compatibility with EVA and ethylene-butyl acrylate copolymer, and can form a stronger interfacial bond with molybdenum-coated magnesium filler treated by epoxidation and siloxaneization. Thus, a stable synergistic network of functional filler, functional polymer and resin matrix is ​​established in the system. Under the action of external force, stress can be transmitted more evenly between the interfaces, reducing stress concentration and microcrack initiation common in inorganic filler filling systems. The resulting insulating sheath layer can still obtain good tensile strength and elongation at break while maintaining a high flame retardancy level.

[0026] 3. This invention also combines functionalized molybdenum-coated magnesium filler, epoxidized polyolefin, and EVA / ethylene-butyl acrylate copolymer matrix. The introduction of silane, siloxane, and epoxy groups improves the interfacial wetting and coating state between the inorganic and organic phases, reduces direct contact between particles, pores, and defect channels, thereby inhibiting electron or ion migration along the interface and improving insulation stability. The ammonium polyphosphate and zinc borate system, together with the molybdenum-coated magnesium filler, promote char formation and smoke suppression during combustion, making the char layer more continuous and dense, reducing the amount of smoke particles and volatiles generated during thermal degradation, and improving light transmittance. At the same time, the flexible segments of siloxane provide flexible buffering for the filler surface, weakening the tendency of embrittlement caused by excessive modulus difference between inorganic particles and resin matrix, so that the material can maintain good toughness and reliability while possessing high flame retardancy, low smoke, and high insulation properties. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In this invention, the content of nano-magnesium hydroxide is 99.9%, and the particle size is 30-50 nm;

[0029] In this invention, KH-560 is 3-(2,3-epoxypropoxy)propyltrimethoxysilane, CAS number 2530-83-8;

[0030] In this invention, D4H is 1,3,5,7-tetramethylcyclotetrasiloxane, CAS number 2370-88-9;

[0031] In this invention, D4 is octamethylcyclotetrasiloxane, CAS number 556-67-2;

[0032] In this invention, the content of ammonium polyphosphate is 99%, and the particle size is 50-80 nm.

[0033] In this invention, KH-570 is 3-(methacryloyloxy)propyltrimethoxysilane, CAS number 2530-85-0;

[0034] In this invention, the VA content in the ethylene-vinyl acetate copolymer is 19%;

[0035] In this invention, the ethylene-butyl acrylate copolymer is designated AC3117, has a content of 99%, and an ester content of 33-37%.

[0036] Example 1

[0037] This embodiment provides a method for preparing molybdenum-coated magnesium filler, including the following steps:

[0038] Step 1: Preparation of molybdenum-coated magnesium particles

[0039] Mix calcium chloride and purified water at a ratio of 1g:3mL until homogeneous to obtain a calcium chloride solution;

[0040] Weigh out 50g of nano magnesium hydroxide, 500mL of deionized water, 30g of sodium molybdate, and 2g of sodium dodecyl sulfate and add them to a reaction flask. Disperse the mixture by sonication for 50min. Fix the reaction flask on an iron stand with a mechanical stirrer. Add 100mL of calcium chloride solution to the reaction flask. Heat the reaction flask to 85℃ and keep it at that temperature for 4h. Cool the reaction flask to room temperature and filter it. Wash the filter cake three times with purified water and then transfer it to a drying oven at 110℃ and keep it at that temperature for 10h to obtain molybdenum-coated magnesium particles.

[0041] Step 2: Preparation of epoxy-modified molybdenum-coated magnesium particles

[0042] Weigh out 50g of molybdenum-coated magnesium particles, 300mL of anhydrous ethanol, and 10g of KH-560 and add them to a reaction flask. Stir the mixture and heat the reaction flask to 50℃. Add 60mL of 3M sodium hydroxide aqueous solution to the reaction flask and keep the mixture at this temperature for 60min. Cool the reaction flask to room temperature, filter the mixture, wash the filter cake with purified water until neutral, and then dry it. Transfer the filter cake to a drying oven at 70℃ and dry it to constant weight to obtain epoxy-modified molybdenum-coated magnesium particles.

[0043] Step 3: Preparation of ammonia-terminated hydrogen-containing siloxanes

[0044] Weigh out 30g of D4H, 100g of D4, and 20mL of 8M sodium hydroxide aqueous solution and add them to the reaction flask. Stir the mixture and heat the reaction flask to 85℃. Keep the mixture at this temperature for 80min. Add 11g of 1,3-bis(aminopropyl)tetramethyldisiloxane to the reaction flask and keep the mixture at this temperature for 3h. Cool the reaction flask to room temperature and add 300mL of toluene and 200mL of purified water. Stir and disperse the mixture for 20min. Allow the mixture to stand and separate the liquids. Wash the organic phase three times with purified water and transfer it to a rotary evaporator at a water bath temperature of 85℃. Remove low-boiling substances by vacuum evaporation to obtain ammonia-terminated hydrogen-containing siloxane.

[0045] Step 4: Preparation of molybdenum-coated magnesium filler

[0046] Weigh 50g of ammonia-terminated hydrogen-containing siloxane and 500mL of toluene and add them to an argon-protected reaction flask. Stir until the system dissolves. Add 75g of epoxy-modified molybdenum-coated magnesium particles to the reaction flask. Heat the reaction flask to 80℃ and maintain the temperature for 60min. Add 15g of 3-buten-1-amine and 1g of chloroplatinic acid to the reaction flask and maintain the temperature for 4h. Apply a negative pressure to -0.1MPa to remove low-boiling substances. Cool the reaction flask to room temperature and add 500mL of anhydrous ethanol. Stir and disperse for 30min. Filter the mixture. Wash the filter cake three times with anhydrous ethanol and dry it. Transfer the filter cake to a drying oven at 60℃ and dry it to constant weight to obtain the molybdenum-coated magnesium filler.

[0047] Example 2

[0048] This embodiment provides a method for preparing molybdenum-coated magnesium filler, including the following steps:

[0049] Step 1: Preparation of molybdenum-coated magnesium particles

[0050] Mix calcium chloride and purified water at a ratio of 1g:3mL until homogeneous to obtain a calcium chloride solution;

[0051] Weigh out 50g of nano magnesium hydroxide, 500mL of deionized water, 35g of sodium molybdate, and 2.5g of sodium dodecyl sulfate and add them to a reaction flask. Disperse the mixture by sonication for 55min. Fix the reaction flask on an iron stand with a mechanical stirrer. Add 100mL of calcium chloride solution to the reaction flask. Heat the reaction flask to 90℃ and keep it at that temperature for 4.5h. Cool the reaction flask to room temperature and filter it. Wash the filter cake three times with purified water and then transfer it to a drying oven at 115℃ and keep it at that temperature for 11h to obtain molybdenum-coated magnesium particles.

[0052] Step 2: Preparation of epoxy-modified molybdenum-coated magnesium particles

[0053] Weigh out 50g of molybdenum-coated magnesium particles, 300mL of anhydrous ethanol, and 15g of KH-560 and add them to a reaction flask. Stir the mixture and heat the reaction flask to 55℃. Add 60mL of 4M sodium hydroxide aqueous solution to the reaction flask and keep the mixture at this temperature for 70min. Cool the reaction flask to room temperature, filter the mixture, wash the filter cake with purified water until neutral, and then dry it. Transfer the filter cake to a drying oven at 75℃ and dry it to constant weight to obtain epoxy-modified molybdenum-coated magnesium particles.

[0054] Step 3: Preparation of ammonia-terminated hydrogen-containing siloxanes

[0055] Weigh out 35g of D4H, 125g of D4, and 25mL of 9M sodium hydroxide aqueous solution and add them to the reaction flask. Stir the mixture and heat the reaction flask to 90℃. Keep the temperature for 90min. Add 13g of 1,3-bis(aminopropyl)tetramethyldisiloxane to the reaction flask and keep the temperature for 4h. Cool the reaction flask to room temperature and add 300mL of toluene and 200mL of purified water. Stir and disperse for 25min. Let the mixture stand and separate the liquids. Wash the organic phase three times with purified water and transfer it to a rotary evaporator with a water bath temperature of 90℃. Remove low-boiling substances by vacuum evaporation to obtain ammonia-terminated hydrogen-containing siloxane.

[0056] Step 4: Preparation of molybdenum-coated magnesium filler

[0057] Weigh 55g of ammonia-terminated hydrogen-containing siloxane and 500mL of toluene into an argon-protected reaction flask and stir until dissolved. Add 80g of epoxy-modified molybdenum-coated magnesium particles to the reaction flask. Heat the reaction flask to 85℃ and maintain the temperature for 70min. Add 20g of 3-buten-1-amine and 1g of chloroplatinic acid to the reaction flask and maintain the temperature for 5h. Apply a negative pressure to -0.1MPa to remove low-boiling substances. Cool the reaction flask to room temperature and add 500mL of anhydrous ethanol. Stir and disperse for 40min. Filter the mixture. Wash the filter cake three times with anhydrous ethanol and dry it. Transfer the filter cake to a drying oven at 65℃ and dry it to constant weight to obtain the molybdenum-coated magnesium filler.

[0058] Example 3

[0059] This embodiment provides a method for preparing molybdenum-coated magnesium filler, including the following steps:

[0060] Step 1: Preparation of molybdenum-coated magnesium particles

[0061] Mix calcium chloride and purified water at a ratio of 1g:3mL until homogeneous to obtain a calcium chloride solution;

[0062] Weigh out 50g of nano magnesium hydroxide, 500mL of deionized water, 40g of sodium molybdate, and 3g of sodium dodecyl sulfate and add them to a reaction flask. Disperse the mixture by sonication for 60min. Fix the reaction flask on an iron stand with a mechanical stirrer. Add 100mL of calcium chloride solution to the reaction flask. Heat the reaction flask to 95℃ and keep it at that temperature for 5h. Cool the reaction flask to room temperature and filter it. Wash the filter cake three times with purified water and then transfer it to a drying oven at 120℃ and keep it at that temperature for 12h to obtain molybdenum-coated magnesium particles.

[0063] Step 2: Preparation of epoxy-modified molybdenum-coated magnesium particles

[0064] Weigh out 50g of molybdenum-coated magnesium particles, 300mL of anhydrous ethanol, and 20g of KH-560 and add them to a reaction flask. Stir the mixture and heat the reaction flask to 60℃. Add 60mL of 5M sodium hydroxide aqueous solution to the reaction flask and keep the mixture at this temperature for 80min. Cool the reaction flask to room temperature, filter the mixture, wash the filter cake with purified water until neutral, and then dry it. Transfer the filter cake to a drying oven at 80℃ and dry it to constant weight to obtain epoxy-modified molybdenum-coated magnesium particles.

[0065] Step 3: Preparation of ammonia-terminated hydrogen-containing siloxanes

[0066] Weigh out 40g of D4H, 150g of D4, and 30mL of 10M sodium hydroxide aqueous solution and add them to a reaction flask. Stir the mixture and heat the reaction flask to 95℃. Keep the mixture at this temperature for 100min. Add 15g of 1,3-bis(aminopropyl)tetramethyldisiloxane to the reaction flask and keep the mixture at this temperature for 5h. Cool the reaction flask to room temperature and add 300mL of toluene and 200mL of purified water. Stir and disperse the mixture for 30min. Allow the mixture to stand and separate the liquids. Wash the organic phase three times with purified water and transfer it to a rotary evaporator at a water bath temperature of 95℃. Remove low-boiling substances by vacuum evaporation to obtain ammonia-terminated hydrogen-containing siloxane.

[0067] Step 4: Preparation of molybdenum-coated magnesium filler

[0068] Weigh 60g of ammonia-terminated hydrogen-containing siloxane and 500mL of toluene and add them to an argon-protected reaction flask. Stir until the system dissolves. Add 85g of epoxy-modified molybdenum-coated magnesium particles to the reaction flask. Heat the reaction flask to 90℃ and maintain the temperature for 80min. Add 25g of 3-buten-1-amine and 1g of chloroplatinic acid to the reaction flask and maintain the temperature for 6h. Apply a negative pressure to -0.1MPa to remove low-boiling substances. Cool the reaction flask to room temperature and add 500mL of anhydrous ethanol. Stir and disperse for 50min. Filter the mixture. Wash the filter cake three times with anhydrous ethanol and dry it. Transfer the filter cake to a drying oven at 70℃ and dry it to constant weight to obtain the molybdenum-coated magnesium filler.

[0069] Example 4

[0070] This embodiment provides a method for preparing epoxidized polyolefins, specifically including the following steps:

[0071] Step ①: Preparation of activated mixed particles

[0072] Weigh out 50g of ammonium polyphosphate, 20g of zinc borate, 13g of KH-570, and 500mL of anhydrous ethanol and add them to a reaction flask. Stir the mixture and heat the reaction flask to 40℃. Add 30mL of 1M sodium hydroxide aqueous solution to the reaction flask and keep it at this temperature for 80min. Cool the reaction flask to room temperature and filter it. Wash the filter cake three times with anhydrous ethanol and then dry it. Transfer the filter cake to a drying oven at 70℃ and dry it to constant weight to obtain activated mixed particles.

[0073] Step ②: Preparation of epoxidized polyolefin

[0074] Azobisisobutyronitrile and toluene were mixed evenly at a ratio of 1g:20mL to obtain an initiator solution;

[0075] Weigh out 70g of butyl acrylate, 50g of vinyl acetate, 20g of dibutyl maleate, 30g of 1,2-epoxy-5-hexene, 50g of activated mixed particles, and 1000mL of toluene. Add these to a reaction flask and stir. Heat the reaction flask to 70℃, add 100mL of initiator solution dropwise, and maintain the temperature for 4 hours. Then heat the reaction flask to 90℃ and remove low-boiling substances by vacuum distillation to obtain epoxidized polyolefin.

[0076] Example 5

[0077] This embodiment provides a method for preparing epoxidized polyolefins, specifically including the following steps:

[0078] Step ①: Preparation of activated mixed particles

[0079] Weigh out 50g of ammonium polyphosphate, 25g of zinc borate, 14.5g of KH-570, and 500mL of anhydrous ethanol and add them to a reaction flask. Stir the mixture and heat the reaction flask to 45℃. Add 40mL of 1.5M sodium hydroxide aqueous solution to the reaction flask and keep the mixture at this temperature for 90min. Cool the reaction flask to room temperature and filter the mixture. Wash the filter cake three times with anhydrous ethanol and then dry it. Transfer the filter cake to a drying oven at 75℃ and dry it to constant weight to obtain activated mixed particles.

[0080] Step ②: Preparation of epoxidized polyolefin

[0081] Azobisisobutyronitrile and toluene were mixed evenly at a ratio of 1g:20mL to obtain an initiator solution;

[0082] Weigh out 75g of butyl acrylate, 55g of vinyl acetate, 25g of dibutyl maleate, 35g of 1,2-epoxy-5-hexene, 55g of activated mixed particles, and 1000mL of toluene. Add these to a reaction flask and stir. Heat the reaction flask to 75℃, add 100mL of initiator solution dropwise, and maintain the temperature for 5 hours. Then heat the reaction flask to 90℃ and remove low-boiling substances by vacuum distillation to obtain epoxidized polyolefin.

[0083] Example 6

[0084] This embodiment provides a method for preparing epoxidized polyolefins, specifically including the following steps:

[0085] Step ①: Preparation of activated mixed particles

[0086] Weigh out 50g of ammonium polyphosphate, 30g of zinc borate, 16g of KH-570, and 500mL of anhydrous ethanol and add them to a reaction flask. Stir the mixture and heat the reaction flask to 50℃. Add 50mL of 2M sodium hydroxide aqueous solution to the reaction flask and keep it at this temperature for 100min. Cool the reaction flask to room temperature and filter it. Wash the filter cake three times with anhydrous ethanol and dry it under vacuum. Transfer the filter cake to a drying oven at 80℃ and dry it to constant weight to obtain activated mixed particles.

[0087] Step ②: Preparation of epoxidized polyolefin

[0088] Azobisisobutyronitrile and toluene were mixed evenly at a ratio of 1g:20mL to obtain an initiator solution;

[0089] Weigh out 80g of butyl acrylate, 60g of vinyl acetate, 30g of dibutyl maleate, 40g of 1,2-epoxy-5-hexene, 60g of activated mixed particles, and 1000mL of toluene. Add these to a reaction flask and stir. Heat the reaction flask to 80℃, add 100mL of initiator solution dropwise, and maintain the temperature for 6 hours. Then heat the reaction flask to 90℃ and remove low-boiling substances by vacuum distillation to obtain epoxidized polyolefin.

[0090] Example 7

[0091] This embodiment provides a halogen-free, low-smoke, high-flame-retardant cable for connecting power sources in new energy vehicles, comprising a conductor and an insulating sheath layer disposed on the outer periphery of the conductor;

[0092] The conductor is formed by several copper wires with insulating layers arranged in parallel to each other;

[0093] The molding method of the insulating sheath layer is as follows: 50 parts by weight of ethylene-vinyl acetate copolymer, 35 parts by weight of ethylene-butyl acrylate copolymer, 26 parts by weight of molybdenum-coated magnesium filler prepared in Example 1, 18 parts by weight of epoxidized polyolefin prepared in Example 4, 0.7 parts by weight of antioxidant 1010, and 0.6 parts by weight of ethylene bis-stearamide are added to a twin-screw extruder. The temperatures of the five temperature zones of the twin-screw extruder are set to 120℃, 125℃, 130℃, 130℃, and 135℃ respectively, and the die temperature is set to 140℃. The mixture is melt-mixed for 2 minutes, extruded and coated on the outside of the conductor, cooled and cured to form an insulating sheath layer with a thickness of 1.5 mm on the outside of the conductor, thus obtaining the cable material.

[0094] Example 8

[0095] This embodiment provides a halogen-free, low-smoke, high-flame-retardant cable for connecting power sources in new energy vehicles, comprising a conductor and an insulating sheath layer disposed on the outer periphery of the conductor;

[0096] The conductor is formed by several copper wires with insulating layers arranged in parallel to each other;

[0097] The molding method of the insulating sheath layer is as follows: 55 parts by weight of ethylene-vinyl acetate copolymer, 40 parts by weight of ethylene-butyl acrylate copolymer, 29 parts by weight of molybdenum-coated magnesium filler prepared in Example 2, 20 parts by weight of epoxidized polyolefin prepared in Example 5, 0.8 parts by weight of antioxidant 1010, and 0.7 parts by weight of ethylene bis-stearamide are added to a twin-screw extruder. The temperatures of the five temperature zones of the twin-screw extruder are set to 120℃, 125℃, 130℃, 130℃, and 135℃ respectively, and the die temperature is set to 140℃. The mixture is melt-mixed for 2.5 minutes, extruded and coated on the outside of the conductor, cooled and cured to form an insulating sheath layer with a thickness of 1.5 mm on the outside of the conductor, thus obtaining the cable material.

[0098] Example 9

[0099] This embodiment provides a halogen-free, low-smoke, high-flame-retardant cable for connecting power sources in new energy vehicles, comprising a conductor and an insulating sheath layer disposed on the outer periphery of the conductor;

[0100] The conductor is formed by several copper wires with insulating layers arranged in parallel to each other;

[0101] The molding method of the insulating sheath layer is as follows: 60 parts by weight of ethylene-vinyl acetate copolymer, 45 parts by weight of ethylene-butyl acrylate copolymer, 32 parts by weight of molybdenum-coated magnesium filler prepared in Example 3, 22 parts by weight of epoxidized polyolefin prepared in Example 6, 0.9 parts by weight of antioxidant 1010, and 0.8 parts by weight of ethylene bis-stearamide are added to a twin-screw extruder. The temperatures of the five temperature zones of the twin-screw extruder are set to 120℃, 125℃, 130℃, 130℃, and 135℃ respectively, and the die temperature is set to 140℃. The mixture is melt-mixed for 3 minutes, extruded and coated on the outside of the conductor, cooled and cured to form an insulating sheath layer with a thickness of 1.5 mm on the outside of the conductor, thus obtaining the cable material.

[0102] Comparative Example 1

[0103] The difference between this comparative example and Example 9 is that, in the preparation of the molybdenum-coated magnesium filler, step 1 is omitted, and the nano-magnesium hydroxide in step 1 is used instead of the molybdenum-coated magnesium particles in step 2.

[0104] Comparative Example 2

[0105] The difference between this comparative example and Example 9 is that, in the preparation of the molybdenum-coated magnesium filler, 3-butene-1-amine and chloroplatinic acid were not added in step 4.

[0106] Comparative Example 3

[0107] The difference between this comparative example and Example 9 is that the molybdenum-coated magnesium filler used is replaced by the epoxy-modified molybdenum-coated magnesium particles prepared in step 2.

[0108] Comparative Example 4

[0109] The difference between this comparative example and Example 9 is that, in the preparation of the epoxidized polyolefin, the activated mixed particles in step ② are replaced by an equal amount of a mixture of ammonium polyphosphate and zinc borate in a weight ratio of 5:3.

[0110] Performance testing:

[0111] The volume resistivity of the insulation sheath of the cable material samples prepared in Examples 7-9 and Comparative Examples 1-4 was determined in accordance with the standard GB / T 31838.2-2019 "Dielectric and resistive properties of solid insulating materials - Part 2: Resistive properties (DC method) - Volume resistivity and volume resistivity".

[0112] The oxygen index of the insulation sheath of the cable material samples prepared in Examples 7-9 and Comparative Examples 1-4 was determined in accordance with the standard GB / T 2406.2-2009 "Determination of flammability by oxygen index method for plastics - Part 2: Room temperature test".

[0113] The light transmittance of the insulation sheath of the cable material samples prepared in Examples 7-9 and Comparative Examples 1-4 was determined in accordance with the standard GB / T 17651.2-2021 "Determination of smoke density of cables or optical fibers under specific conditions - Part 2: Test procedures and requirements".

[0114] The tensile strength and elongation at break of the insulation and sheath layers of the cable material samples prepared in Examples 7-9 and Comparative Examples 1-4 were determined in accordance with the standard GB / T 2951.11-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers - Part 11: General Test Methods - Thickness and Dimensional Measurements - Mechanical Properties Tests". The specific test data are shown in Table 1 below.

[0115] Table 1 - Performance Test Data of Samples

[0116]

[0117] Data Analysis:

[0118] The volume resistivity of the insulation sheath layer of the halogen-free, low-smoke, high-flame-retardant cable sample prepared by this invention reaches 8.34 × 10⁻⁶. 12 -9.42×10 12 The oxygen index reaches 38.6-39.5%, the light transmittance reaches 73.8-75.2%, the tensile strength reaches 15.3-15.8 MPa, and the elongation at break reaches 285-296%. All performance test data are better than those of the comparative example. This indicates that the present invention, by preparing molybdenum-coated magnesium filler and then activating it with ammonium polyphosphate and zinc borate, participates in the construction of epoxidized polyolefin. Through multi-level interface regulation and flame retardant synergistic design, the dispersibility, compatibility and interfacial bonding strength of inorganic fillers in organic resin are improved. At the same time, the heat absorption and cooling, densification and char formation and smoke suppression effects during combustion are enhanced. Thus, the resulting insulating sheath layer has good processability and formability, and also has high volume resistivity, oxygen index, light transmittance, tensile strength and elongation at break.

[0119] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A halogen-free, low-smoke, high-flame-retardant cable for connecting power sources in new energy vehicles, comprising a conductor and an insulating sheath layer disposed around the outer periphery of the conductor, characterized in that, The insulating sheath layer, by weight, comprises: 50-60 parts of ethylene-vinyl acetate copolymer, 35-45 parts of ethylene-butyl acrylate copolymer, 26-32 parts of molybdenum-coated magnesium filler, 18-22 parts of epoxidized polyolefin, 0.7-0.9 parts of antioxidant, and 0.6-0.8 parts of lubricant.

2. The halogen-free, low-smoke, high-flame-retardant cable for connecting power supplies in new energy vehicles according to claim 1, characterized in that, The preparation method of molybdenum-coated magnesium filler is as follows: Under the protection of an inert gas atmosphere, ammonia-terminated hydrogen-containing siloxane and toluene are mixed and stirred until the system is dissolved. Epoxy-modified molybdenum-coated magnesium particles are added to the reaction system. The reaction system is heated to 80-90℃ and kept at this temperature for 60-80 min. 3-Butene-1-amine and platinum catalyst are added to the reaction system and kept at this temperature for 4-6 h. After post-treatment, molybdenum-coated magnesium filler is obtained.

3. The halogen-free, low-smoke, high-flame-retardant cable for connecting power supplies in new energy vehicles according to claim 2, characterized in that, The ratio of ammonia-terminated hydrogen-containing siloxane, toluene, epoxy-modified molybdenum-coated magnesium particles, 3-butene-1-amine, and platinum catalyst is 10-12g:100mL:15-17g:3-5g:0.2g. The platinum catalyst is chloroplatinic acid. The post-treatment includes: after the reaction is complete, the reaction system is subjected to negative pressure to remove low-boiling substances by vacuum evaporation, the reaction system is cooled to room temperature, anhydrous ethanol is added to the reaction system, the mixture is stirred and dispersed for 30-50 minutes, filtered, the filter cake is washed three times with anhydrous ethanol and then dried, the filter cake is transferred to a drying oven at 60-70℃ and dried to constant weight to obtain molybdenum-coated magnesium packing.

4. The halogen-free, low-smoke, high-flame-retardant cable for connecting power supplies in new energy vehicles according to claim 2, characterized in that, The preparation method of ammonia-terminated hydrogen-containing siloxane is as follows: D4H, D4 and catalyst are mixed and stirred, the reaction system is heated to 85-95℃ and kept at this temperature for 80-100 min, 1,3-bis(aminopropyl)tetramethyldisiloxane is added to the reaction system and kept at this temperature for 3-5 h, and then post-processed to obtain ammonia-terminated hydrogen-containing siloxane.

5. A halogen-free, low-smoke, high-flame-retardant cable for connecting power supplies to new energy vehicles according to claim 4, characterized in that, The ratio of D4H, D4, catalyst, and 1,3-bis(aminopropyl)tetramethyldisiloxane is 3-4g:10-15g:2-3mL:1.1-1.5g. The catalyst is an 8-10M sodium hydroxide aqueous solution. The post-treatment includes: after the reaction is complete, the reaction system is cooled to room temperature, toluene and purified water are added to the reaction system, the mixture is stirred and dispersed for 20-30 minutes, the mixture is allowed to stand and separated, the organic phase is washed three times with purified water and then transferred to a rotary evaporator with a water bath temperature of 85-95℃ to remove low-boiling substances under reduced pressure, to obtain an ammonia-terminated hydrogen-containing siloxane.

6. A halogen-free, low-smoke, high-flame-retardant cable for connecting power supplies to new energy vehicles according to claim 2, characterized in that, Epoxy-modified molybdenum-coated magnesium particles are obtained through the following steps: A1. Mix nano-magnesium hydroxide, deionized water, sodium molybdate and sodium dodecyl sulfate, ultrasonically disperse for 50-60 min, add calcium chloride solution to the reaction system, heat the reaction system to 85-95℃, keep it at the temperature for 4-5 h, and then perform post-treatment to obtain molybdenum-coated magnesium particles. A2. Mix and stir molybdenum-coated magnesium particles, anhydrous ethanol, and KH-560. Heat the reaction system to 50-60℃, add sodium hydroxide aqueous solution to the reaction system, keep the reaction at this temperature for 60-80 minutes, and then perform post-treatment to obtain epoxy-modified molybdenum-coated magnesium particles.

7. A halogen-free, low-smoke, high-flame-retardant cable for connecting power supplies to new energy vehicles according to claim 6, characterized in that, In step A1, the ratio of nano-magnesium hydroxide, deionized water, sodium molybdate, sodium dodecyl sulfate, and calcium chloride solution is 5g:50mL:3-4g:0.2-0.3g:10mL. The calcium chloride solution is composed of calcium chloride and purified water at a ratio of 1g:3mL. The post-treatment includes: after the reaction is complete, cooling the reaction system to room temperature, filtering, washing the filter cake three times with purified water, and then transferring it to a drying oven at 110-120℃ for drying for 10-12 hours. The reaction process yields molybdenum-coated magnesium particles. In step A2, the ratio of the molybdenum-coated magnesium particles, anhydrous ethanol, KH-560, and sodium hydroxide aqueous solution is 5g:30mL:1-2g:6mL, and the concentration of the sodium hydroxide aqueous solution is 3-5M. The post-treatment includes: after the reaction is complete, the reaction system is cooled to room temperature, filtered, the filter cake is washed with purified water until neutral, dried, and the filter cake is transferred to a drying oven at 70-80℃ and dried to constant weight to obtain epoxy-modified molybdenum-coated magnesium particles.

8. The halogen-free, low-smoke, high-flame-retardant cable for connecting power supplies in new energy vehicles according to claim 1, characterized in that, Epoxidized polyolefins are obtained by the following steps: B1. Mix and stir ammonium polyphosphate, zinc borate, KH-570 and anhydrous ethanol. Heat the reaction system to 40-50℃, add sodium hydroxide aqueous solution to the reaction system, keep the reaction at the temperature for 80-100 min, and then perform post-treatment to obtain activated mixed particles. B2. Mix butyl acrylate, vinyl acetate, dibutyl maleate, 1,2-epoxy-5-hexene, activated mixed particles, and toluene, and stir. Heat the reaction system to 70-80℃, add initiator solution dropwise to the reaction system, keep the reaction at this temperature for 4-6 hours, and then perform post-treatment to obtain epoxidized polyolefin.

9. A halogen-free, low-smoke, high-flame-retardant cable for connecting power supplies to new energy vehicles according to claim 8, characterized in that, In step B1, the ratio of ammonium polyphosphate, zinc borate, KH-570, anhydrous ethanol, and sodium hydroxide aqueous solution is 5g:2-3g:1.3-1.6g:50mL:3-5mL, and the concentration of the sodium hydroxide aqueous solution is 1-2M. The post-treatment includes: after the reaction is complete, cooling the reaction system to room temperature, filtering, washing the filter cake three times with anhydrous ethanol, drying it, transferring the filter cake to a drying oven at 70-80℃, and drying it to constant weight to obtain activated mixed particles; In step B2, the ratio of butyl acrylate, vinyl acetate, dibutyl maleate, 1,2-epoxy-5-hexene, activated mixed particles, toluene, and initiator solution is 7-8g:5-6g:2-3g:3-4g:5-6g:100mL:10mL. The initiator solution is composed of azobisisobutyronitrile and toluene at a ratio of 1g:20mL. The post-treatment includes: after the reaction is complete, the reaction system is heated to 90°C, and low-boiling substances are removed by vacuum distillation to obtain epoxidized polyolefin.

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