Aging-resistant new energy vehicle charging cable and preparation method thereof

Abstract

The application discloses an anti-aging new energy vehicle charging cable and a preparation method thereof, and belongs to the technical field of cable preparation. The application is used for solving the technical problem that the anti-aging performance and the flame-retardant performance of the new energy vehicle charging cable in the prior art need to be further improved. The anti-aging new energy vehicle charging cable comprises, from inside to outside, a conductive wire core, an armored layer and an anti-aging layer. In the application, modified POSS is introduced into a polyurethane prepolymer chain to obtain an anti-aging polyurethane by delaying desolubilization, and cerium dioxide is modified by phenyl phosphoric acid to obtain flame-retardant cerium oxide. The anti-aging modified polyurethane, the flame-retardant cerium oxide and an additive are melt granulated and extruded on the outside of the armored layer to obtain the new energy vehicle charging cable which has the properties of anti-aging, flame retardation and high mechanical performance.

Description

Technical Field

[0001] This invention relates to the field of cable manufacturing technology, specifically to an aging-resistant charging cable for new energy vehicles and its manufacturing method. Background Technology

[0002] With the rapid increase in the number of new energy vehicles and the power of DC fast charging, charging cables are constantly subjected to repeated cycles of heating and cooling under high current and high power conditions. They also have to withstand the combined effects of outdoor sun exposure, rain, salt spray, mud, and mechanical bending and twisting. Thermal aging and ultraviolet aging have become key factors limiting the lifespan of charging cables. Existing new energy vehicle charging cables often extend their service life by improving the heat resistance of the sheath, optimizing structural design, and increasing safety margins. However, under prolonged high-temperature current carrying, frequent dragging and bending, and the coupling effects of harsh environments, sheath cracking, hardening, crazing, and electrical performance degradation are still common.

[0003] Currently, commonly used materials for the sheathing of charging cables for new energy vehicles include PVC, cross-linked polyethylene (XLPE), thermoplastic polyurethane (TPU), thermoplastic elastomers (such as TPEE and TPV), and rubber materials such as chloroprene rubber and EPDM. To improve aging resistance, the modification methods commonly used in engineering are mainly: introducing antioxidants such as hindered phenols and phosphites, as well as UV absorbers and hindered amine light stabilizers into the matrix to inhibit thermo-oxidative and photo-aging; or blending inorganic or carbon-based fillers such as nano-SiO2, layered silicates, and carbon black to construct a physical cross-linked network to improve wear resistance and crack resistance. However, the above solutions still have limitations in terms of the synergistic effect of high-temperature long-cycle aging and flame retardancy.

[0004] In existing technologies, small-molecule antioxidants and light stabilizers are prone to migration, volatilization, or failure during long-term thermal cycling, leading to a decrease in the material's anti-aging ability in the later stages. At the same time, although traditional peroxide crosslinking and radiation crosslinking can improve thermal stability, the increased rigidity of the crosslinking network makes the sheath more prone to strain concentration and cracking under repeated bending conditions. Secondly, inorganic particles such as nano-SiO2, layered silicates, and carbon black mainly provide physical reinforcement, but their dispersibility and interfacial bonding are limited, making it difficult to effectively block free radical chain degradation at high temperatures. They also lack sufficient synergistic inhibition of thermo-oxidative aging and ultraviolet aging. Since the above modification strategies are mostly localized improvements, they lack an overall synergistic optimization mechanism between flame retardancy, mechanical stability, and aging resistance, making it difficult to meet the higher requirements of new energy vehicle charging cables for high reliability, long life, and adaptability to complex outdoor environments.

[0005] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an aging-resistant new energy vehicle charging cable and its preparation method, which solves the technical problem that the aging resistance and flame retardant properties of existing new energy vehicle charging cables need to be further improved.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A new energy vehicle charging cable with aging resistance includes a conductive core, an armor layer and an aging-resistant layer arranged sequentially from the inside to the outside. The conductive core includes three parallel cable cores and an insulating rubber covering the outside of the cable cores. The armor layer is formed by spirally wrapping galvanized steel strip around the conductive cores. The aging-resistant layer is formed by melt-extruding flame-retardant and aging-resistant masterbatch around the armor layer.

[0009] The flame-retardant and aging-resistant masterbatch comprises the following components by weight: 60-80 parts of aging-resistant modified polyurethane, 10-13 parts of flame-retardant cerium oxide, and 1-3 parts of auxiliary additives.

[0010] The aging-resistant modified polyurethane is prepared by the following steps:

[0011] A1. Place polytetrahydrofuran, dibutyltin dilaurate and toluene in a reaction vessel under nitrogen atmosphere and stir. Add isophorone diisocyanate. Heat the reaction vessel to 75-85℃ and keep it at this temperature for 1-2 hours to obtain modified polyurethane prepolymer liquid.

[0012] A2. Place the modified polyurethane prepolymer liquid in a reaction vessel under nitrogen atmosphere and stir. Heat the reaction vessel to 60-70℃, add 2,2-dimethylolpropionic acid and 1,4-butanediol, and keep the reaction at this temperature for 0.5-1h. Add the modified POSS solution, heat the reaction vessel to 80-90℃, and keep the reaction at this temperature for 4-6h. Post-treatment yields aging-resistant modified polyurethane.

[0013] The preparation reaction principle of aging-resistant modified polyurethane is as follows:

[0014] During the reaction, the terminal hydroxyl groups of polytetrahydrofuran undergo an addition reaction of -OH and -NCO with isophorone diisocyanate under the catalysis of dibutyltin dilaurate, forming a urethane bond. Due to the excess of isophorone diisocyanate, a modified polyurethane prepolymer with -NCO terminal groups is finally formed. In step A2, the terminal -NCO of the prepolymer in the modified polyurethane prepolymer undergoes a further chain extension reaction with the hydroxyl groups of 2,2-dimethylolpropionic acid, introducing structural units with side carboxyl groups. At the same time, 1,4-butanediol acts as a small molecule chain extender and reacts with the remaining -NCO. Subsequently, the epoxy groups in the modified POSS solution can undergo ring-opening reactions with the hydroxyl groups in the polyurethane segments and the carboxyl groups introduced by 2,2-dimethylolpropionic acid, forming chemical bonds to obtain aging-resistant modified polyurethane.

[0015] Furthermore, in step A1, the ratio of polytetrahydrofuran, dibutyltin dilaurate, and toluene is 10-15g:0.4-0.6g:180-200mL, and the molar amount of isophorone diisocyanate is 0.55 times the total molar amount of hydroxyl groups in polytetrahydrofuran and modified POSS.

[0016] Further, in step A2, the ratio of the modified polyurethane prepolymer, 2,2-dimethylolpropionic acid, 1,4-butanediol, and modified POSS solution is 30-40 mL: 0.5-1 g: 3-4 g: 4-6 mL. The modified POSS solution is composed of modified POSS and N,N-dimethylformamide in a ratio of 1 g: 10 mL. The post-treatment step includes: after the reaction is completed, heating the reaction vessel to 100-110°C and distilling under reduced pressure until no liquid is collected, thereby obtaining the aging-resistant modified polyurethane.

[0017] Furthermore, the modified POSS is prepared by the following steps:

[0018] B1. Deionized water, ethanol, triethoxy-p-phenylmethylsilane and tetrabutylammonium fluoride aqueous solution were placed in a reaction vessel and stirred. The reaction was carried out at room temperature for 2-4 days. The prepolymer POSS was obtained after post-treatment.

[0019] B2. Prepolymer POSS, tetrahydrofuran and formic acid aqueous solution are placed in a reaction vessel and stirred. The reaction is carried out at room temperature for 1-2 days. γ-glycidyl etheroxypropyltrimethoxysilane is added and the reaction is carried out at room temperature for 1-2 days. The modified POSS is obtained after post-treatment.

[0020] The preparation reaction principle of modified POSS is as follows:

[0021] During the reaction, the silicon-oxygen bonds of triethoxy-p-phenylmethylsilane are hydrolyzed to silanols under the action of tetrabutylammonium fluoride. The silanols further undergo condensation reactions and gradually self-assemble to form a polyhedral cage-like silsesquioxane framework. In step B2, the residual Si-OH on the surface of the prepolymer POSS is further activated under the regulation of formic acid and undergoes a co-condensation reaction with γ-glycidoxypropyltrimethoxysilane to obtain modified POSS containing phenyl and epoxy groups.

[0022] Further, in step B1, the ratio of deionized water, ethanol, triethoxy-p-phenylmethylsilane and tetrabutylammonium fluoride aqueous solution is 10-15mL:50-70mL:2-4g:0.5-1mL, and the concentration of tetrabutylammonium fluoride aqueous solution is 0.5-1mol / L. The post-processing step includes: after the reaction is completed, filtration is performed, the filter cake is transferred to an oven at a temperature of 50-60℃, and dried to constant weight to obtain prepolymer POSS.

[0023] Further, in step B2, the ratio of the prepolymer POSS, tetrahydrofuran, formic acid aqueous solution, and γ-glycidyl etheroxypropyltrimethoxysilane is 2-4g:60-80mL:0.5-1mL:1-2mg, and the concentration of the formic acid aqueous solution is 0.5-1mol / L. The post-processing step includes: after the reaction is completed, adding 1g of calcium chloride to the reaction solution, stirring for 20-24h, filtering, transferring the filtrate to a rotary evaporator at a temperature of 80-90℃, and evaporating until no liquid is collected to obtain modified POSS.

[0024] Furthermore, the preparation method of the flame-retardant cerium oxide is as follows: cerium dioxide, ethanol and deionized water are placed in a reaction vessel and stirred, phenyl phosphoric acid is added and stirred for 5-10 min, ammonia water is added to adjust the pH to 3-4, the reaction vessel is heated to 50-60℃ and kept at the temperature for 3-5 h, and the flame-retardant cerium oxide is obtained after post-treatment.

[0025] The preparation reaction principle of flame-retardant cerium oxide is as follows:

[0026] During the reaction, the cerium dioxide surface contains a large number of -Ce-OH and uncoordinated Ce. 3+ / Ce 4+ At the site, phenylphosphoric acid partially dissociates into -P(O)(OH)O under weakly acidic conditions. - / -P(O)O2 2- This gives it stronger metalophilic properties, enabling it to undergo dehydration condensation with the -Ce-OH on the cerium dioxide surface to form a stable covalent PO-Ce bond. Additionally, the P=O of some phenylphosphonic acid can also act as an electron donor, reacting with the uncoordinated Ce on the surface. 3+ / Ce 4+ The formation of coordinate bonds at the sites, along with the formation of an organophosphorus shell on the surface of cerium dioxide by phenylphosphonic acid, results in flame-retardant cerium oxide.

[0027] Furthermore, the ratio of cerium dioxide, ethanol, deionized water, and phenylphosphoric acid is 8-10g:100-120mL:60-80mL:1-2g, and the concentration of ammonia is 20-25wt%. The post-treatment steps include: after the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed 2-4 times with deionized water and ethanol, transferred to an oven at 50-60℃, and dried to constant weight to obtain flame-retardant cerium oxide.

[0028] This invention also proposes a method for preparing an aging-resistant charging cable for new energy vehicles, comprising the following steps:

[0029] S1. Add aging-resistant modified polyurethane, flame-retardant cerium oxide and auxiliary additives to a twin-screw extruder, melt extrude, granulate, and obtain flame-retardant and aging-resistant masterbatch.

[0030] S2. Wrap the three parallel cable cores covered with insulating rubber with wrapping tape to obtain conductive wire cores;

[0031] S3. Add the conductive wire core to the armoring machine and use galvanized steel strip to spirally wrap it to obtain the armor layer.

[0032] S4. Add flame-retardant and aging-resistant masterbatch to a twin-screw extruder and extrude it onto the outside of the armor layer to form an aging-resistant layer, thus obtaining a new energy vehicle charging cable.

[0033] Further, in step S1, the auxiliary additive is composed of plasticizer, lubricant and antioxidant in a mass ratio of 4:3:1. The plasticizer is one or more of dioctyl phthalate, dioctyl sebacate and dioctyl adipate. The lubricant is one or more of oleic acid, paraffin and calcium stearate. The antioxidant is one or more of 2,6-di-tert-butyl-4-methylphenol, 4,4'-thiobis(6-tert-butyl-3-methylphenol) and N,N'-diphenyl-p-phenylenediamine.

[0034] Furthermore, in step S1, the temperatures of the eight temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 150℃, 150℃, 165℃, 165℃, 180℃, 180℃, 190℃, and 190℃ respectively. The main engine speed of the twin-screw extruder is 120-160 rpm, and the pressure is 80-120 bar.

[0035] Furthermore, in step S2, the wrapping tape is one or more of PET wrapping tape, non-woven wrapping tape, and fiberglass tape, and the insulating rubber is one or more of ethylene propylene rubber, neoprene rubber, and silicone rubber.

[0036] Furthermore, in step S4, the temperatures of the eight temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 160℃, 160℃, 175℃, 175℃, 180℃, 180℃, 195℃, and 195℃ respectively. The main engine speed of the twin-screw extruder is 120-160 rpm, and the pressure is 80-120 bar.

[0037] The present invention has the following beneficial effects:

[0038] 1. The cage-like silica skeleton of the modified POSS introduced into the aging-resistant modified polyurethane in this invention has excellent thermal stability and antioxidant properties. After being incorporated into the polyurethane side chains, it can significantly improve the overall heat aging resistance of the cable material, inhibit the degradation of polyurethane soft segments under long-term high temperature, electrical heating, and external environmental thermal stress, and improve the structural stability and service life of the cable under high-temperature conditions. Secondly, the modified POSS modified with glycidyl etheroxypropyl silane possesses active functional groups, which can chemically bond or strongly interact with polyurethane segments, allowing the modified POSS to be uniformly dispersed in the matrix, forming a nanoscale inorganic dot-like cross-linked structure. These micro-cross-linked points... It can effectively restrict the movement of polyurethane chain segments, improve the mechanical strength and deformation recovery ability of cable materials. In addition, the introduction of modified POSS can improve the flame retardant properties of materials. Its inorganic silicon-oxygen structure can form a dense silicon dioxide protective layer during combustion, which, together with flame-retardant cerium oxide, improves the carbon layer quality and barrier effect of the sheath under high temperature and flame environment, delays thermal decomposition, and improves the safety of cables under extreme conditions such as short circuits and overloads. Finally, the nano-size and low surface energy characteristics of modified POSS help to improve the hydrophobicity and UV aging resistance of materials, so that cables can still maintain the stability of flexibility, mechanical properties and electrical properties under long-term outdoor exposure conditions.

[0039] 2. The flame-retardant cerium oxide introduced in this invention has reversible Ce... 3+ / Ce 4+ The step-valence state transition capability of cerium oxide effectively captures free radicals at its surface oxygen vacancies, inhibiting the chain degradation reaction of polymers in hot and oxygen environments. This significantly improves the thermal stability and aging resistance of the cable material, allowing it to maintain excellent mechanical strength and flexibility even under long-term outdoor exposure. Secondly, the cerium oxide particles modified with phenylphosphoric acid form a stable phosphorus-containing coordination structure on the surface. This structure improves the compatibility and dispersibility of cerium oxide in the polyurethane matrix, avoiding performance degradation caused by agglomeration. On the other hand, it can promote the char formation reaction of the polymer matrix when heated, forming a denser and more complete heat-insulating carbon layer during combustion. This helps to suppress smoke, isolate oxygen, and block heat transfer, greatly improving the flame retardant performance of the material. At the same time, the good inorganic stability of cerium oxide can also enhance the material's resistance to ultraviolet aging, reducing surface cracks, powdering, and strength loss caused by photo-oxidation, enabling the cable to maintain long-term reliability in high ultraviolet and high humidity outdoor environments.

[0040] 3. The aging-resistant modified polyurethane in this invention improves the material's heat resistance, UV aging resistance, and mechanical stability by introducing a POSS nanostructure. Meanwhile, the flame-retardant cerium oxide, with its excellent free radical scavenging ability and high-temperature stability, effectively inhibits the thermo-oxidative degradation reaction of the polymer during high temperature and combustion. During combustion, cerium oxide can promote the formation of a dense carbon layer in the polyurethane matrix, which, together with the inorganic phase formed by the modified POSS, constructs a heat and oxygen barrier, significantly reducing the heat release rate and smoke density. The two components achieve synergistic improvement in structural reinforcement, anti-aging, and flame retardancy, enabling the new energy vehicle charging cable to simultaneously possess excellent long-term service stability and high safety and reliability. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the overall cross-sectional structure of the present invention.

[0043] In the diagram: 1. Conductive core; 1-1. Cable core; 1-2. Insulating rubber; 2. Armor layer; 3. Aging-resistant layer. Detailed Implementation

[0044] 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.

[0045] The polytetrahydrofuran used in this invention was purchased from Shandong Xuchen Chemical Technology Co., Ltd., with a molecular weight of 1000 and conforming to national standards.

[0046] The cerium dioxide used in this invention was purchased from Shandong Xiangzhao New Materials Co., Ltd., and its density is 7.13 g / cm³. 3 The content is 99.9%.

[0047] Example 1

[0048] This embodiment provides a method for preparing modified POSS, including the following steps:

[0049] Step I: Preparation of prepolymerized POSS

[0050] Weigh out 100 mL of deionized water, 500 mL of ethanol, 20 g of triethoxy-p-phenylmethylsilane and 5 mL of 0.5 mol / L tetrabutylammonium fluoride aqueous solution and place them in a reaction vessel and stir. React at room temperature for 2 days. After the reaction is complete, filter the mixture and transfer the filter cake to an oven at 50 °C and dry it to constant weight to obtain prepolymer POSS.

[0051] Step II: Preparation of modified POSS

[0052] Weigh out 20g of prepolymer POSS, 600mL of tetrahydrofuran, and 5mL of 0.5mol / L formic acid aqueous solution and place them in a reaction vessel. Stir and react at room temperature for 1 day. Add 10g of γ-glycidyl etheroxypropyltrimethoxysilane and react at room temperature for 1 day. After the reaction is complete, add 10g of calcium chloride to the reaction solution and stir for 20 hours. Filter the solution and transfer the filtrate to a rotary evaporator at 80℃. Evaporate until no liquid is collected to obtain modified POSS.

[0053] Example 2

[0054] This embodiment provides a method for preparing modified POSS, including the following steps:

[0055] Step I: Preparation of prepolymerized POSS

[0056] Weigh out 125 mL of deionized water, 600 mL of ethanol, 30 g of triethoxy-p-phenylmethylsilane and 7.5 mL of 0.75 mol / L tetrabutylammonium fluoride aqueous solution and place them in a reaction vessel and stir. React at room temperature for 3 days. After the reaction is complete, filter the mixture and transfer the filter cake to an oven at 55 °C and dry it to constant weight to obtain prepolymer POSS.

[0057] Step II: Preparation of modified POSS

[0058] Weigh out 30g of prepolymer POSS, 700mL of tetrahydrofuran, and 7.5mL of 0.75mol / L formic acid aqueous solution and place them in a reaction vessel. Stir and react at room temperature for 1.5 days. Add 15g of γ-glycidoxypropyltrimethoxysilane and react at room temperature for 1.5 days. After the reaction is complete, add 10g of calcium chloride to the reaction solution and stir for 22 hours. Filter the solution and transfer the filtrate to a rotary evaporator at 85℃. Evaporate until no liquid is collected to obtain modified POSS.

[0059] Example 3

[0060] This embodiment provides a method for preparing modified POSS, including the following steps:

[0061] Step I: Preparation of prepolymerized POSS

[0062] Weigh out 150 mL of deionized water, 700 mL of ethanol, 40 g of triethoxy-p-phenylmethylsilane and 10 mL of 1 mol / L tetrabutylammonium fluoride aqueous solution and place them in a reaction vessel and stir. React at room temperature for 4 days. After the reaction is complete, filter the mixture and transfer the filter cake to an oven at 60 °C and dry it to constant weight to obtain prepolymer POSS.

[0063] Step II: Preparation of modified POSS

[0064] Weigh out 40g of prepolymer POSS, 800mL of tetrahydrofuran, and 10mL of 1mol / L formic acid aqueous solution and place them in a reaction vessel. Stir and react at room temperature for 2 days. Add 20g of γ-glycidyl etheroxypropyltrimethoxysilane and react at room temperature for 2 days. After the reaction is complete, add 10g of calcium chloride to the reaction solution and stir for 24 hours. Filter the solution and transfer the filtrate to a rotary evaporator at 90℃. Evaporate until no liquid is collected to obtain modified POSS.

[0065] Example 4

[0066] This embodiment provides a method for preparing aging-resistant modified polyurethane, including the following steps:

[0067] Step ①: Preparation of modified polyurethane prepolymer solution

[0068] Weigh out 100g of polytetrahydrofuran, 4g of dibutyltin dilaurate and 1800mL of toluene and place them in a reaction vessel under nitrogen atmosphere and stir. Add isophorone diisocyanate at 0.55 times the total molar amount of hydroxyl groups in polytetrahydrofuran and modified POSS. Heat the reaction vessel to 75℃ and keep it at this temperature for 1h to obtain the modified polyurethane prepolymer.

[0069] Step 2: Preparation of aging-resistant modified polyurethane

[0070] The modified POSS and N,N-dimethylformamide were mixed evenly at a ratio of 1g:10mL to obtain a modified POSS solution for later use.

[0071] Weigh 300 mL of modified polyurethane prepolymer and place it in a nitrogen-protected reactor. Stir the reactor and heat it to 60°C. Add 5 g of 2,2-dimethylolpropionic acid and 30 g of 1,4-butanediol and keep the mixture at this temperature for 0.5 h. Add 40 mL of modified POSS solution and heat the reactor to 80°C. Keep the mixture at this temperature for 4 h. After the reaction is complete, heat the reactor to 100°C and distill under reduced pressure until no liquid is collected, thus obtaining the aging-resistant modified polyurethane.

[0072] Example 5

[0073] This embodiment provides a method for preparing aging-resistant modified polyurethane, including the following steps:

[0074] Step ①: Preparation of modified polyurethane prepolymer solution

[0075] Weigh out 125g of polytetrahydrofuran, 5g of dibutyltin dilaurate and 1900mL of toluene and place them in a reaction vessel under nitrogen atmosphere and stir. Add isophorone diisocyanate at 0.55 times the total molar amount of hydroxyl groups in polytetrahydrofuran and modified POSS. Heat the reaction vessel to 80℃ and keep it at this temperature for 1.5h to obtain the modified polyurethane prepolymer.

[0076] Step 2: Preparation of aging-resistant modified polyurethane

[0077] The modified POSS and N,N-dimethylformamide were mixed evenly at a ratio of 1g:10mL to obtain a modified POSS solution for later use.

[0078] Weigh 350 mL of modified polyurethane prepolymer and place it in a nitrogen-protected reactor. Stir the reactor and heat it to 65°C. Add 7.5 g of 2,2-dimethylolpropionic acid and 35 g of 1,4-butanediol. Keep the reactor at this temperature for 1 hour. Add 50 mL of modified POSS solution and heat the reactor to 85°C. Keep the reactor at this temperature for 5 hours. After the reaction is complete, heat the reactor to 105°C and distill under reduced pressure until no liquid is collected, thus obtaining the aging-resistant modified polyurethane.

[0079] Example 6

[0080] This embodiment provides a method for preparing aging-resistant modified polyurethane, including the following steps:

[0081] Step ①: Preparation of modified polyurethane prepolymer solution

[0082] Weigh out 150g of polytetrahydrofuran, 6g of dibutyltin dilaurate and 2000mL of toluene and place them in a reaction vessel under nitrogen atmosphere and stir. Add isophorone diisocyanate at 0.55 times the total molar amount of hydroxyl groups in polytetrahydrofuran and modified POSS. Heat the reaction vessel to 85℃ and keep it at this temperature for 2 hours to obtain the modified polyurethane prepolymer.

[0083] Step 2: Preparation of aging-resistant modified polyurethane

[0084] The modified POSS and N,N-dimethylformamide were mixed evenly at a ratio of 1g:10mL to obtain a modified POSS solution for later use.

[0085] Weigh 400 mL of modified polyurethane prepolymer and place it in a nitrogen-protected reactor. Stir the reactor and heat it to 70°C. Add 10 g of 2,2-dimethylolpropionic acid and 40 g of 1,4-butanediol. Keep the reactor at this temperature for 1 hour. Add 60 mL of modified POSS solution and heat the reactor to 90°C. Keep the reactor at this temperature for 6 hours. After the reaction is complete, heat the reactor to 110°C and distill under reduced pressure until no liquid is collected, thus obtaining the aging-resistant modified polyurethane.

[0086] Example 7

[0087] This embodiment provides a method for preparing flame-retardant cerium oxide, including the following steps:

[0088] Weigh out 80g of cerium dioxide, 1000mL of ethanol and 600mL of deionized water and place them in a reaction vessel. Stir, add 10g of phenylphosphoric acid and stir for 5min. Add 20wt% ammonia water to adjust the pH to 3. Heat the reaction vessel to 50℃ and keep it at that temperature for 3h. After the reaction is complete, wait for the reaction system to cool to room temperature, filter, wash the filter cake twice with deionized water and ethanol, transfer it to an oven at 50℃ and dry it to constant weight to obtain flame-retardant cerium oxide.

[0089] Example 8

[0090] This embodiment provides a method for preparing flame-retardant cerium oxide, including the following steps:

[0091] Weigh out 900g of cerium dioxide, 1100mL of ethanol and 700mL of deionized water and place them in a reaction vessel. Stir, add 15g of phenylphosphoric acid and stir for 7min. Add 22.5wt% ammonia water to adjust the pH to 3.5. Heat the reaction vessel to 55℃ and keep it at that temperature for 4h. After the reaction is complete, wait for the reaction system to cool to room temperature, filter, wash the filter cake three times with deionized water and ethanol, transfer it to an oven at 55℃ and dry it to constant weight to obtain flame-retardant cerium oxide.

[0092] Example 9

[0093] This embodiment provides a method for preparing flame-retardant cerium oxide, including the following steps:

[0094] Weigh 100g of cerium dioxide, 1200mL of ethanol and 800mL of deionized water and place them in a reaction vessel and stir. Add 20g of phenylphosphoric acid and stir for 10min. Add 25wt% ammonia water to adjust the pH to 4. Heat the reaction vessel to 60℃ and keep it at that temperature for 5h. After the reaction is complete, wait for the reaction system to cool to room temperature, filter it, wash the filter cake 4 times with deionized water and ethanol, transfer it to an oven at 60℃ and dry it to constant weight to obtain flame-retardant cerium oxide.

[0095] Example 10

[0096] This embodiment provides a method for preparing an aging-resistant charging cable for new energy vehicles, including the following steps:

[0097] Step 1: Preparation of flame-retardant and aging-resistant masterbatch

[0098] Dioctyl sebacate, oleic acid and 2,6-di-tert-butyl-4-methylphenol were mixed evenly in a mass ratio of 4:3:1 to obtain an auxiliary additive, which was then set aside.

[0099] Weigh out the following by weight: 60 parts of the aging-resistant modified polyurethane prepared in Example 4, 10 parts of the flame-retardant cerium oxide prepared in Example 7, and 1 part of auxiliary additives. Add them to a twin-screw extruder, melt extrude, and granulate to obtain flame-retardant and aging-resistant masterbatch.

[0100] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 150℃, 150℃, 165℃, 165℃, 180℃, 180℃, 190℃, and 190℃ respectively. The main motor speed of the twin-screw extruder is 120 rpm, and the pressure is 80 bar.

[0101] Step 2: Prepare conductive wire core

[0102] Three parallel cable cores 1-1, each covered with insulating rubber 1-2, are wrapped with wrapping tape to obtain conductive core 1.

[0103] Step 3: Prepare the armor layer

[0104] The conductive core 1 is added to the armoring machine, and galvanized steel strip is used for spiral wrapping to obtain the armor layer 2.

[0105] Step 4: Prepare the aging-resistant layer

[0106] Flame-retardant and aging-resistant masterbatch is added to a twin-screw extruder and extruded onto the outside of the armor layer 2 to form the aging-resistant layer 3, thus obtaining a new energy vehicle charging cable.

[0107] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 160℃, 160℃, 175℃, 175℃, 180℃, 180℃, 195℃, and 195℃ respectively. The main motor speed of the twin-screw extruder is 120 rpm, and the pressure is 80 bar.

[0108] Example 11

[0109] This embodiment provides a method for preparing an aging-resistant charging cable for new energy vehicles, including the following steps:

[0110] Step 1: Preparation of flame-retardant and aging-resistant masterbatch

[0111] Dioctyl sebacate, oleic acid and 2,6-di-tert-butyl-4-methylphenol were mixed evenly in a mass ratio of 4:3:1 to obtain an auxiliary additive, which was then set aside.

[0112] Weigh out the following by weight: 70 parts of the aging-resistant modified polyurethane prepared in Example 5, 11.5 parts of the flame-retardant cerium oxide prepared in Example 8, and 2 parts of auxiliary additives. Add them to a twin-screw extruder, melt extrude, and granulate to obtain flame-retardant and aging-resistant masterbatch.

[0113] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 150℃, 150℃, 165℃, 165℃, 180℃, 180℃, 190℃, and 190℃ respectively. The main motor speed of the twin-screw extruder is 140 rpm, and the pressure is 100 bar.

[0114] Step 2: Prepare conductive wire core

[0115] Three parallel cable cores 1-1, each covered with insulating rubber 1-2, are wrapped with wrapping tape to obtain conductive core 1.

[0116] Step 3: Prepare the armor layer

[0117] The conductive core 1 is added to the armoring machine, and galvanized steel strip is used for spiral wrapping to obtain the armor layer 2.

[0118] Step 4: Prepare the aging-resistant layer

[0119] Flame-retardant and aging-resistant masterbatch is added to a twin-screw extruder and extruded onto the outside of the armor layer 2 to form the aging-resistant layer 3, thus obtaining a new energy vehicle charging cable.

[0120] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 160℃, 160℃, 175℃, 175℃, 180℃, 180℃, 195℃, and 195℃ respectively. The main motor speed of the twin-screw extruder is 140 rpm, and the pressure is 100 bar.

[0121] Example 12

[0122] This embodiment provides a method for preparing an aging-resistant charging cable for new energy vehicles, including the following steps:

[0123] Step 1: Preparation of flame-retardant and aging-resistant masterbatch

[0124] Dioctyl sebacate, oleic acid and 2,6-di-tert-butyl-4-methylphenol were mixed evenly in a mass ratio of 4:3:1 to obtain an auxiliary additive, which was then set aside.

[0125] Weigh out the following by weight: 80 parts of the aging-resistant modified polyurethane prepared in Example 6, 13 parts of the flame-retardant cerium oxide prepared in Example 9, and 3 parts of auxiliary additives. Add them to a twin-screw extruder, melt extrude, and granulate to obtain flame-retardant and aging-resistant masterbatch.

[0126] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 150℃, 150℃, 165℃, 165℃, 180℃, 180℃, 190℃, and 190℃ respectively. The main motor speed of the twin-screw extruder is 160 rpm, and the pressure is 120 bar.

[0127] Step 2: Prepare conductive wire core

[0128] Three parallel cable cores 1-1, each covered with insulating rubber 1-2, are wrapped with wrapping tape to obtain conductive core 1.

[0129] Step 3: Prepare the armor layer

[0130] The conductive core 1 is added to the armoring machine, and galvanized steel strip is used for spiral wrapping to obtain the armor layer 2.

[0131] Step 4: Prepare the aging-resistant layer

[0132] Flame-retardant and aging-resistant masterbatch is added to a twin-screw extruder and extruded onto the outside of the armor layer 2 to form the aging-resistant layer 3, thus obtaining a new energy vehicle charging cable.

[0133] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 160℃, 160℃, 175℃, 175℃, 180℃, 180℃, 195℃, and 195℃ respectively. The main motor speed of the twin-screw extruder is 160 rpm, and the pressure is 120 bar.

[0134] Comparative Example 1

[0135] The difference between this comparative example and Example 12 is that the modified POSS solution was omitted in step ② when preparing the aging-resistant modified polyurethane.

[0136] Comparative Example 2

[0137] The difference between this comparative example and Example 12 is that the flame-retardant cerium oxide was omitted when preparing the flame-retardant and aging-resistant masterbatch in step (1).

[0138] Performance testing:

[0139] The tensile strength, elongation at break, change rate of tensile strength after thermal aging test, change rate of elongation at break, and crack condition after ozone exposure of the new energy vehicle charging cables prepared in Examples 10-12 and Comparative Examples 1-23 were tested in accordance with the standard GB / T 33594-2017 "Cables for Electric Vehicle Charging".

[0140] The flame retardancy ratings of the new energy vehicle charging cables prepared in Examples 10-12 and Comparative Examples 1-23 were tested in accordance with the standard GB 31247-2014 "Classification of Flammability of Cables and Optical Fibers".

[0141] See Table 1 for specific data.

[0142] Table 1 - Performance Test Data for Each Sample

[0143]

[0144] Data Analysis:

[0145] Comparative analysis of the data in the table above shows that the tensile strength of the new energy vehicle charging cable prepared by this invention is 15.9 N / mm². 2 The elongation at break is 344.6%, the change rate of tensile strength after heat aging test is 5.6%, the change rate of elongation at break is 7.1%, and there are no cracks after ozone exposure and the flame retardant level is B1.

[0146] This invention obtains prepolymer POSS by hydrolysis and polycondensation of triethoxy-p-phenylmethylsilane under tetrabutylammonium fluoride catalysis, and achieves surface organic modification by reaction with glycidyl etheroxypropyltrimethoxysilane. Further, a polyurethane prepolymer is prepared by reacting polytetrahydrofuran and isophorone diisocyanate under dibutyltin dilaurate catalysis, and then further chained by adding 2,2-dimethylolpropionic acid, 1,4-butanediol, and modified POSS. Reduced pressure solvent removal yields aging-resistant modified polyurethane. Flame-retardant cerium oxide is obtained by deposition modification of cerium dioxide under phenyl phosphoric acid regulation. The modified polyurethane, flame-retardant cerium oxide, and auxiliary additives are melt-granulated in a twin-screw extruder to form a masterbatch, which is then extruded onto the outer armor layer to produce a new energy vehicle charging cable. This process not only improves its aging resistance but also its flame retardant and mechanical properties.

[0147] The above description is merely an example and illustration of the structure 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 structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

[0148] 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.

[0149] 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. An aging-resistant charging cable for new energy vehicles, characterized in that, It includes a conductive core (1), an armor layer (2) and an aging-resistant layer (3) arranged sequentially from the inside to the outside. The conductive core includes three parallel cable cores (1-1) and an insulating rubber (1-2) covering the outside of the cable core. The armor layer (2) is formed by spirally wrapping galvanized steel strip around the outside of the conductive core (1). The aging-resistant layer (3) is formed by melt extruding flame-retardant and aging-resistant masterbatch around the outside of the armor layer (2). The flame-retardant and aging-resistant masterbatch comprises the following components by weight: 60-80 parts of aging-resistant modified polyurethane, 10-13 parts of flame-retardant cerium oxide, and 1-3 parts of auxiliary additives. The aging-resistant modified polyurethane is prepared by the following steps: A1. Place polytetrahydrofuran, dibutyltin dilaurate and toluene in a reaction vessel under nitrogen atmosphere and stir. Add isophorone diisocyanate. Heat the reaction vessel to 75-85℃ and keep it at this temperature for 1-2 hours to obtain modified polyurethane prepolymer liquid. A2. Place the modified polyurethane prepolymer liquid in a reaction vessel under nitrogen atmosphere and stir. Heat the reaction vessel to 60-70℃, add 2,2-dimethylolpropionic acid and 1,4-butanediol, and keep the reaction at this temperature for 0.5-1h. Add the modified POSS solution, heat the reaction vessel to 80-90℃, and keep the reaction at this temperature for 4-6h. Post-treatment yields aging-resistant modified polyurethane. Modified POSS was prepared by the following steps: B1. Deionized water, ethanol, triethoxy-p-phenylmethylsilane and tetrabutylammonium fluoride aqueous solution were placed in a reaction vessel and stirred. The reaction was carried out at room temperature for 2-4 days. The prepolymer POSS was obtained after post-treatment. B2. Prepolymer POSS, tetrahydrofuran and formic acid aqueous solution are placed in a reaction vessel and stirred. The reaction is carried out at room temperature for 1-2 days. γ-glycidyl etheroxypropyltrimethoxysilane is added and the reaction is carried out at room temperature for 1-2 days. The modified POSS is obtained after post-treatment. The method for preparing the flame-retardant cerium oxide is as follows: cerium dioxide, ethanol and deionized water are placed in a reaction vessel and stirred. Phenylic acid is added and stirred for 5-10 minutes. Ammonia water is added to adjust the pH to 3-4. The reaction vessel is heated to 50-60℃ and kept at that temperature for 3-5 hours. The flame-retardant cerium oxide is then obtained through post-treatment.

2. The aging-resistant charging cable for new energy vehicles according to claim 1, characterized in that, In step A1, the ratio of polytetrahydrofuran, dibutyltin dilaurate, and toluene is 10-15g:0.4-0.6g:180-200mL, and the molar amount of isophorone diisocyanate is 0.55 times the total molar amount of hydroxyl groups in polytetrahydrofuran and modified POSS. In step A2, the ratio of modified polyurethane prepolymer, 2,2-dimethylolpropionic acid, 1,4-butanediol, and modified POSS solution is 30-40mL:0.5-1g:3-4g:4-6mL, and the modified POSS solution is composed of modified POSS and N,N-dimethylformamide in a ratio of 1g:10mL.

3. The aging-resistant charging cable for new energy vehicles according to claim 1, characterized in that, In step B1, the ratio of deionized water, ethanol, triethoxy-p-phenylmethylsilane, and tetrabutylammonium fluoride aqueous solution is 10-15 mL: 50-70 mL: 2-4 g: 0.5-1 mL, and the concentration of tetrabutylammonium fluoride aqueous solution is 0.5-1 mol / L; in step B2, the ratio of prepolymer POSS, tetrahydrofuran, formic acid aqueous solution, and γ-glycidoxypropyltrimethoxysilane is 2-4 g: 60-80 mL: 0.5-1 mL: 1-2 g, and the concentration of formic acid aqueous solution is 0.5-1 mol / L.

4. The aging-resistant charging cable for new energy vehicles according to claim 1, characterized in that, The ratio of cerium dioxide, ethanol, deionized water and phenylphosphoric acid is 8-10g:100-120mL:60-80mL:1-2g, and the concentration of ammonia is 20-25wt%.

5. A method for preparing an aging-resistant new energy vehicle charging cable as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Add aging-resistant modified polyurethane, flame-retardant cerium oxide and auxiliary additives to a twin-screw extruder, melt extrude, granulate, and obtain flame-retardant and aging-resistant masterbatch. S2. Wrap the three parallel cable cores (1-1) covered with insulating rubber (1-2) with wrapping tape to obtain the conductive core (1). S3. Add the conductive wire core (1) to the armoring machine and use galvanized steel strip to spirally wrap it to obtain the armor layer (2). S4. Add flame-retardant and aging-resistant masterbatch to a twin-screw extruder and extrude it onto the outside of the armor layer (2) to form an aging-resistant layer (3), thus obtaining a new energy vehicle charging cable.

6. The method for preparing an aging-resistant new energy vehicle charging cable according to claim 5, characterized in that, In step S1, the auxiliary additive is composed of plasticizer, lubricant and antioxidant in a mass ratio of 4:3:1; in step S2, the wrapping tape is one or more of PET wrapping tape, non-woven wrapping tape and glass fiber tape, and the insulating rubber is one or more of ethylene propylene rubber, neoprene rubber and silicone rubber.

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