A new energy vehicle charging cable with compression resistance, high temperature resistance and easy heat dissipation

Abstract

The present invention relates to the field of cables, and discloses a new energy vehicle charging cable with compressive resistance, high temperature resistance and easy heat dissipation. The charging cable sequentially includes a tape layer, a copper wire braided overall shielding layer, and an outer sheath layer from the inside to the outside. Three power cores, one ground wire core, two signal control cores, and two auxiliary power cores are arranged in the tape layer. The power core includes a conductor and an insulating layer extruded on the outer surface of the conductor. The outer sheath layer comprises the following raw materials in parts by weight: 70-90 parts of PVC resin, 20-30 parts of thermoplastic polyurethane elastomer, 10-15 parts of modified additive, 2-5 parts of hyperbranched flame retardant, 5-10 parts of plasticizer, 4-7 parts of stabilizer, and 1-3 parts of lubricant. By adding the modified additive and the hyperbranched flame retardant, the present invention endows the material with excellent mechanical properties, flame retardant properties, heat-oxygen aging resistance and heat resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of cables, and particularly relates to a new energy vehicle charging cable with compressive resistance, high temperature resistance and easy heat dissipation. Background Art

[0002] New energy vehicles refer to vehicles that use unconventional vehicle fuels as power sources (or use conventional vehicle fuels and adopt new in-vehicle power devices), integrate advanced technologies in vehicle power control and drive, and form vehicles with advanced technical principles, new technologies and new structures. They can effectively reduce environmental pollution, save energy and protect the environment, and have received support from various countries and regions. Not only is the new energy vehicle industry developed on a large scale, but also the supporting charging piles and charging stations are widely built and put into operation.

[0003] When charging existing new energy vehicles, due to the long charging time, fires and other situations often occur. Therefore, the charging cables used must have good high temperature resistance and flame retardant effects. In order to improve the flame retardant performance of cable materials in the prior art, a large amount of inorganic flame retardants are often added. Currently, the commonly used small molecule structure flame retardants mainly include: halogen-containing flame retardants, phosphorus-based flame retardants, silicon-based flame retardants, nitrogen-based flame retardants and composite flame retardants, etc. Since the small molecule flame retardants have poor compatibility with materials, they will reduce the mechanical properties of the materials, and will also make the viscosity, compatibility and flexibility of polymer materials poor. Moreover, in the charging area, vehicles come and go, and the cable needs to have excellent compressive resistance. At the same time, during the use of the charging pile cable, it is in an environment of frequent dragging and long-term exposure to the outdoor, and the load current value is relatively large. The heat generated by the high current is likely to cause the cable material to heat up and age. Therefore, the charging cable material should have good heat and oxygen aging resistance and good mechanical properties. Summary of the Invention

[0004] To solve the deficiencies mentioned in the above background art, the purpose of the present invention is to provide a new energy vehicle charging cable with compressive resistance, high temperature resistance and easy heat dissipation. By adding modified additives and hyperbranched flame retardants, the sheath layer material is given excellent mechanical properties, flame retardant properties, heat and oxygen aging resistance and heat resistance.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A new energy vehicle charging cable with compressive resistance, high temperature resistance and easy heat dissipation. The charging cable sequentially includes a tape layer, a copper wire braided total shielding layer, and an outer sheath layer from inside to outside. There are three power cores, one ground wire core, two signal control cores, and two auxiliary power cores in the tape layer. The power core includes a conductor and an insulating layer extruded on the outer surface of the conductor. The signal control core has two signal cores, and the outer surface of the signal core is sequentially coated with an aluminum-plastic composite tape shielding layer and a copper wire braided shielding layer. A filling layer is filled in the gaps between the tape layer and the three power cores, one ground wire core, two signal control cores, and two auxiliary power cores;

[0007] The outer sheath layer comprises the following raw materials in parts by weight: 70-90 parts of PVC resin, 20-30 parts of polyurethane thermoplastic elastomer, 10-15 parts of modified additive, 2-5 parts of hyperbranched flame retardant, 5-10 parts of plasticizer, 4-7 parts of stabilizer, and 1-3 parts of lubricant;

[0008] The modified additive is prepared by grafting reaction of silica-coated ammonium polyphosphate grafted with amino-functionalized graphene oxide treated with γ-glycidyl ether oxypropyltrimethoxysilane and amino-functionalized boron nitride nanosheets; The hyperbranched flame retardant is a hyperbranched flame retardant synthesized from DOPO, terephthalaldehyde and 1,5-naphthalenediamine to form a DOPO derivative and then using phosphorus oxychloride as a linker.

[0009] Preferably, the plasticizer is one or a combination of dioctyl adipate, dimethyl phthalate, dioctyl phthalate, diisodecyl phthalate; The stabilizer is one of calcium-zinc stabilizer and organotin stabilizer; The lubricant is one of polyethylene wax and oxidized polyethylene wax.

[0010] Preferably, the preparation method of the modified additive comprises the following steps:

[0011] A. Take ethanol and deionized water in a reactor, stir at 40-50 °C for 10-15 min, add ammonium polyphosphate, OP-10 and ammonia water and stir and mix, then add tetraethyl orthosilicate and stir and react for 1-2 h. After the reaction is completed, cool to room temperature, filter, wash and dry to prepare silica-coated ammonium polyphosphate;

[0012] B. Dissolve γ-glycidyl ether oxypropyltrimethoxysilane in a mixed solution of ethanol and deionized water to obtain a silane-containing ethanol solution. Ultrasonically disperse silica-coated ammonium polyphosphate in absolute ethanol and place it in a reactor, adjust the pH value to 4-5 with dilute hydrochloric acid, then place it at 75-90 °C, add the silane-containing ethanol solution and stir and react for 5-8 h. After the reaction is completed, filter, wash and dry to prepare functionalized silica-coated ammonium polyphosphate;

[0013] C. Graphene oxide is taken and ultrasonically dispersed in deionized water to obtain a dispersion. p-Phenylenediamine is dissolved in deionized water and then added to the dispersion. After ultrasonic mixing, the mixture is placed at 30 - 50 °C for reaction for 18 - 24 h. After the reaction is completed, it is filtered, washed, and dried to prepare amino-functionalized graphene oxide.

[0014] D. Amino-functionalized graphene oxide and functionalized silica-coated ammonium polyphosphate are taken and placed in a reactor. Deionized water is added for ultrasonic dispersion, and the mixture is placed at 35 - 50 °C for reaction for 18 - 24 h. After the reaction is completed, it is filtered, washed, and dried to prepare a composite filler.

[0015] E. The composite filler is ultrasonically dispersed in deionized water, and amino-functionalized boron nitride nanosheets are added and stirred and mixed. The pH value of the system is adjusted to 7 - 9 with a 10 - 20% sodium carbonate solution by mass fraction, and then carbodiimide and N-hydroxysuccinimide are added, and the mixture is stirred and reacted for 3 - 5 h. After the reaction is completed, it is filtered and dried to prepare a modified additive.

[0016] Preferably, in step D, the mass ratio of amino-functionalized graphene oxide to functionalized silica-coated ammonium polyphosphate is 1 - 3:1.

[0017] Preferably, in step E, the mass ratio of the composite filler to amino-functionalized boron nitride nanosheets is 0.75 - 1.2:1.

[0018] Preferably, the preparation method of the amino-functionalized boron nitride nanosheets in step E includes the following steps: Boron nitride and urea are taken and placed in a ball milling tank, deionized water and steel balls are added for ball milling. After the ball milling is completed, the reaction solution is centrifuged at 950 - 1100 r / min for 10 - 20 min, the upper suspension is collected and centrifuged at 4500 - 5000 / min for 30 - 40 min, and the lower precipitate is taken and dried to prepare amino-functionalized boron nitride nanosheets.

[0019] Preferably, the steel balls are a mixture of steel balls with diameters of 2 mm, 5 mm, and 10 mm added in a number ratio of 4:2:1, the rotation speed of the ball milling is 750 - 900 r / min, and the ball milling time is 7 - 10 h.

[0020] Preferably, the preparation method of the hyperbranched flame retardant includes the following steps:

[0021] (1) 1,5-Naphthalenediamine is taken and placed in a reactor, and an ethanol solvent is added and mixed evenly. p-Phthalaldehyde is dissolved in ethanol and then added to the reactor. The mixture is placed at 55 - 70 °C for condensation reflux reaction for 4 - 6 h, and then DOPO is dissolved in ethanol and added to the reactor, and the temperature is raised to 75 - 90 °C for reaction for 5 - 7 h. After the reaction is completed, it is filtered, washed, and dried to prepare a DOPO derivative.

[0022] (2) Take DOPO derivative, triethylamine and acetonitrile solvent in a reactor. React while passing nitrogen and place it at 0 - 4 °C. Add an acetonitrile solution containing phosphorus oxychloride and react for 1 - 2 h. Then transfer it to an oil bath at 45 - 60 °C and reflux under nitrogen for 18 - 24 h. After the reaction is completed, filter, wash and dry to prepare a hyperbranched flame retardant.

[0023] Preferably, in the step (2), the molar ratio of the DOPO derivative to phosphorus oxychloride is 1.5:1 - 1.2.

[0024] For the new energy vehicle charging cable with compressive resistance, high temperature resistance and easy heat dissipation as described above, the preparation method of the outer sheath layer material includes the following steps:

[0025] S1. Weigh each raw material by weight. Take PVC resin, plasticizer and stabilizer in a mixer and stir and mix them. Set the temperature of the mixer to 60 - 80 °C. Then add the modified additive, hyperbranched flame retardant and lubricant and continue to stir and mix. At this time, set the temperature of the mixer to 100 - 120 °C, carry out mixing and extrusion granulation to obtain masterbatch.

[0026] S2. Knead the masterbatch and polyurethane elastomer by weight and then put them into a twin-screw extruder for extrusion molding to prepare the outer sheath layer material.

[0027] Advantages of the present invention:

[0028] The present invention first coats a layer of silica particle layer on the surface of ammonium polyphosphate flame retardant. Then, the silicon hydroxyl group at one end of γ-glycidoxypropyltrimethoxysilane hydrolyzes and undergoes a condensation reaction with the hydroxyl group on the surface of silica-coated ammonium polyphosphate to prepare functionalized silica-coated ammonium polyphosphate containing epoxy groups. At the same time, the present invention uses the amino group at one end of the antioxidant p-phenylenediamine to undergo a grafting reaction with the epoxy group in the structure of graphene oxide to prepare amino-functionalized graphene oxide. Then, the amino-functionalized graphene oxide is grafted with functionalized silica-coated ammonium polyphosphate, and the amino group in the structure of amino-functionalized graphene oxide reacts with the epoxy group in the structure of functionalized silica-coated ammonium polyphosphate to prepare a composite filler. At the same time, the present invention uses boron nitride and urea as raw materials and synthesizes amino-functionalized boron nitride nanosheets by ball milling method. Under the participation of a carboxyl activator, the composite filler and the amino-functionalized boron nitride nanosheets undergo an amidation reaction to prepare a modified additive. Among them, graphene oxide and boron nitride nanosheets have excellent mechanical properties and can be used as thermal conductive fillers at the same time, improving the thermal conductivity of the material and thus helping the material to dissipate heat. The addition of the modified additive of the present invention can endow the material with excellent mechanical properties, flame retardant properties, heat-aging resistance and heat resistance.

[0029] The present invention synthesizes a DOPO derivative using DOPO, terephthalaldehyde, and 1,5-naphthalenediamine as raw materials. 1,5-naphthalenediamine has good thermal stability and can release smoke and flame-retardant gases that inhibit combustion at high temperatures. The aldehyde groups at both ends of terephthalaldehyde react with one of the amino groups in the 1,5-naphthalenediamine structure to form an N=C bond, and then the P-H bond in the DOPO structure undergoes an addition reaction with the N=C bond to prepare the DOPO derivative. At the same time, phosphorus oxychloride is used as a linker to make the P-Cl group contained therein undergo a substitution reaction with the amino group in the DOPO derivative structure to prepare a hyperbranched flame retardant, which can not only achieve excellent flame retardant effects but also avoid affecting the mechanical properties of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 is a schematic structural diagram of a new energy vehicle charging cable with high compressive resistance, high temperature resistance, and easy heat dissipation according to the present invention.

[0032] In the figure: 1 - ground cable core, 2 - power core, 21 - conductor, 22 - insulating layer, 3 - signal control core, 31 - signal cable core, 32 - aluminum-plastic composite tape shielding layer, 33 - copper wire braided shielding layer, 4 - auxiliary power core, 5 - filling layer, 6 - tape layer, 7 - copper wire braided overall shielding layer, 8 - outer sheath layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0034] Such as Figure 1As shown in the figure, a new energy vehicle charging cable with compressive resistance, high temperature resistance and easy heat dissipation includes, from the inside to the outside, a tape layer 6, a copper wire braided total shielding layer 7, and an outer sheath layer 8. Inside the non-woven tape layer 6, there are three power cores 2, one ground wire core 1, two signal control cores 3, and two auxiliary power cores 4. The power core 2 includes a conductor 21 and a cross-linked polyethylene insulation layer 22 extruded on the outer surface of the conductor. The signal control core 3 has two signal cores 31. The outer surface of the signal core 31 is successively coated with an aluminum-plastic composite tape shielding layer 32 and a copper wire braided shielding layer 33. A polypropylene filling cord filling layer 5 is filled in the gaps between the tape layer 6 and the three power cores 2, one ground wire core 1, two signal control cores 3, and two auxiliary power cores 4.

[0035] Example 1 The preparation method of a modified additive includes the following steps:

[0036] A. Take 150 mL of ethanol and 50 mL of deionized water in a reactor, place it at 50 °C and stir for 10 min. Add 50 g of ammonium polyphosphate, 1 g of OP-10, and 17 g of 25% ammonia water and stir to mix. Then add 10 g of tetraethyl orthosilicate and stir for 2 h. After the reaction is completed, cool to room temperature, filter, wash, and dry to prepare ammonium polyphosphate coated with silica.

[0037] B. Dissolve 0.25 g of γ-glycidoxypropyltrimethoxysilane in a mixed solution of 10 mL of ethanol and 10 mL of deionized water to obtain a silane-containing ethanol solution. Ultrasonically disperse 2.5 g of ammonium polyphosphate coated with silica in 200 mL of absolute ethanol and place it in a reactor. Adjust the pH value to 4 with dilute hydrochloric acid, then place it at 85 °C, add the silane-containing ethanol solution and stir for 7 h. After the reaction is completed, filter, wash, and dry to prepare functionalized ammonium polyphosphate coated with silica.

[0038] C. Ultrasonically disperse 0.8 g of graphene oxide in 100 mL of deionized water to obtain a dispersion. Dissolve 1.5 g of p-phenylenediamine in 100 mL of deionized water and add it to the dispersion. Ultrasonically mix and place it at 45 °C for 24 h. After the reaction is completed, filter, wash, and dry to prepare amino-functionalized graphene oxide.

[0039] D. Take 1.5 g of amino-functionalized graphene oxide and 1 g of functionalized ammonium polyphosphate coated with silica in a reactor, add 180 mL of deionized water and ultrasonically disperse it. Place it at 50 °C for 24 h. After the reaction is completed, filter, wash, and dry to prepare a composite filler.

[0040] E. Take 1.1 g of the composite filler and ultrasonically disperse it in 200 mL of deionized water. Add 1 g of amino-functionalized boron nitride nanosheets and stir to mix. Adjust the pH value of the system to 8 with a 15% sodium carbonate solution. Then add 0.4 g of carbodiimide and 0.5 g of N-hydroxysuccinimide, and stir and react for 4 h. After the reaction is completed, filter by suction and dry to prepare the modified additive.

[0041] Among them, the preparation method of the amino-functionalized boron nitride nanosheets includes the following steps: Take 2 g of boron nitride and 100 g of urea in a ball mill jar, add 150 mL of deionized water and steel balls with diameters of 2 mm, 5 mm, and 10 mm (the number ratio is 4:2:1) for ball milling. The ball milling speed is 800 r / min, and the ball milling time is 8 h. After the ball milling is completed, place the reaction solution under the condition of 1000 r / min and centrifuge for 15 min. Collect the upper suspension and continue to centrifuge for 30 min under the condition of 5000 / min. Take the lower precipitate and dry it to prepare the amino-functionalized boron nitride nanosheets.

[0042] Example 2 A preparation method of a hyperbranched flame retardant includes the following steps:

[0043] (1) Take 15.8 g of 1,5-naphthalenediamine in a reactor, add 150 mL of ethanol solvent and mix evenly. Take 6.7 g of terephthalaldehyde, dissolve it in 50 mL of ethanol, and then add it to the reactor. Place it under reflux condensation reaction at 65 °C for 5 h. Then take 16 g of DOPO, dissolve it in 100 mL of ethanol, and add it to the reactor. Heat up to 80 °C and react for 6 h. After the reaction is completed, filter, wash, and dry to prepare the DOPO derivative.

[0044] (2) Take 13.97 g of the DOPO derivative, 3.34 g of triethylamine, and 200 mL of acetonitrile solvent in a reactor. React while passing nitrogen and place it at 4 °C. Add 40 mL of an acetonitrile solution containing 1.82 g of phosphorus oxychloride and react for 2 h. Then transfer it to an oil bath at 50 °C and reflux under nitrogen for 24 h. After the reaction is completed, filter by suction, wash, and dry to prepare the hyperbranched flame retardant.

[0045] Example 3 An outer sheath layer comprises the following raw materials in parts by weight: 72 parts of PVC resin, 20 parts of polyurethane thermoplastic elastomer, 10 parts of the modified additive prepared in Example 1, 2 parts of the hyperbranched flame retardant prepared in Example 2, 5 parts of plasticizer dioctyl adipate, 4 parts of calcium-zinc stabilizer, and 1 part of lubricant polyethylene wax.

[0046] The preparation method of the above outer sheath layer material includes the following steps:

[0047] S1. Weigh each raw material by weight parts. Take PVC resin, plasticizer and stabilizer and stir and mix them in a mixer. Set the temperature of the mixer to 75°C, then add the modified additive, hyperbranched flame retardant and lubricant and continue to stir and mix. At this time, set the temperature of the mixer to 110°C, carry out mixing and extrusion granulation to obtain the masterbatch.

[0048] S2. Knead the masterbatch and polyurethane elastomer by weight parts and then put them into a twin-screw extruder for extrusion molding to prepare the outer sheath layer material.

[0049] Example 4. An outer sheath layer comprises the following raw materials by weight parts: 80 parts of PVC resin, 25 parts of polyurethane thermoplastic elastomer, 12 parts of the modified additive prepared in Example 1, 4 parts of the hyperbranched flame retardant prepared in Example 2, 7 parts of dimethyl phthalate as plasticizer, 6 parts of organotin stabilizer, and 2 parts of oxidized polyethylene wax as lubricant.

[0050] The preparation method of the above outer sheath layer material is the same as that of Example 3.

[0051] Example 5. An outer sheath layer comprises the following raw materials by weight parts: 88 parts of PVC resin, 30 parts of polyurethane thermoplastic elastomer, 15 parts of the modified additive prepared in Example 1, 5 parts of the hyperbranched flame retardant prepared in Example 2, 8 parts of dioctyl adipate as plasticizer, 7 parts of calcium-zinc stabilizer, and 3 parts of polyethylene wax as lubricant.

[0052] The preparation method of the above outer sheath layer material is the same as that of Example 3.

[0053] Comparative Example 1. A preparation method of a modified additive comprises the following steps:

[0054] Take 150 mL of ethanol and 50 mL of deionized water in a reactor, place it at 50°C and stir for 10 min, add 50 g of ammonium polyphosphate, 1 g of OP-10 and 17 g of 25% ammonia water by mass fraction and stir and mix, then add 10 g of tetraethyl orthosilicate and stir and react for 2 h. After the reaction is completed, cool to room temperature, filter, wash and dry to prepare the modified additive.

[0055] Comparative Example 2. A preparation method of a modified additive comprises the following steps:

[0056] A. Take 150 mL of ethanol and 50 mL of deionized water in a reactor, place it at 50°C and stir for 10 min, add 50 g of ammonium polyphosphate, 1 g of OP-10 and 17 g of 25% ammonia water by mass fraction and stir and mix, then add 10 g of tetraethyl orthosilicate and stir and react for 2 h. After the reaction is completed, cool to room temperature, filter, wash and dry to prepare ammonium polyphosphate coated with silica.

[0057] B. Take 0.25 g of γ - glycidoxypropyltrimethoxysilane and dissolve it in a mixed solution of 10 mL of ethanol and 10 mL of deionized water to obtain a silane - containing ethanol solution. Ultrasonically disperse 2.5 g of silica - coated ammonium polyphosphate in 200 mL of absolute ethanol and place it in a reactor. Adjust the pH value to 4 with dilute hydrochloric acid, then place it at 85 °C, add the silane - containing ethanol solution, and stir - react for 7 h. After the reaction is completed, filter, wash, and dry to prepare functionalized silica - coated ammonium polyphosphate;

[0058] C. Take 0.8 g of graphene oxide and ultrasonically disperse it in 100 mL of deionized water to obtain a dispersion. Take 1.5 g of p - phenylenediamine, dissolve it in 100 mL of deionized water, and then add it to the dispersion. Ultrasonically mix and react at 45 °C for 24 h. After the reaction is completed, filter, wash, and dry to prepare amino - functionalized graphene oxide;

[0059] D. Take 1.5 g of amino - functionalized graphene oxide and 1 g of functionalized silica - coated ammonium polyphosphate in a reactor, add 180 mL of deionized water, ultrasonically disperse, place it at 50 °C, and react for 24 h. After the reaction is completed, filter, wash, and dry to prepare a modified additive.

[0060] Comparative Example 3 An outer sheath layer comprises the following raw materials in parts by weight: 88 parts of PVC resin, 30 parts of polyurethane thermoplastic elastomer, 15 parts of the modified additive prepared in Comparative Example 1, 5 parts of the hyperbranched flame retardant prepared in Example 2, 8 parts of plasticizer dioctyl adipate, 7 parts of calcium - zinc stabilizer, and 3 parts of lubricant polyethylene wax.

[0061] The preparation method of the above - mentioned outer sheath layer material is the same as that in Example 3.

[0062] Comparative Example 4 An outer sheath layer comprises the following raw materials in parts by weight: 88 parts of PVC resin, 30 parts of polyurethane thermoplastic elastomer, 15 parts of the modified additive prepared in Comparative Example 2, 5 parts of the hyperbranched flame retardant prepared in Example 2, 8 parts of plasticizer dioctyl adipate, 7 parts of calcium - zinc stabilizer, and 3 parts of lubricant polyethylene wax.

[0063] The preparation method of the above - mentioned outer sheath layer material is the same as that in Example 3.

[0064] Comparative Example 5 An outer sheath layer comprises the following raw materials in parts by weight: 88 parts of PVC resin, 30 parts of polyurethane thermoplastic elastomer, 15 parts of the modified additive prepared in Example 1, 8 parts of plasticizer dioctyl adipate, 7 parts of calcium - zinc stabilizer, and 3 parts of lubricant polyethylene wax.

[0065] The preparation method of the above - mentioned outer sheath layer material is the same as that in Example 3.

[0066] Performance testing

[0067] (1) Flame retardancy test: The sheath layer materials prepared in Examples 3-5 and Comparative Examples 3-5 were made into test samples with specifications of 100 mm × 6.5 mm × 3 mm. Referring to GB / T 2406.2-2009, the limiting oxygen index of the test samples was measured to evaluate the flame retardancy of the samples. Generally speaking, the larger the limiting oxygen index, the better the flame retardancy, and vice versa. The data results are shown in Table 1.

[0068] Table 1 Test results of the flame retardancy of the samples

[0069]

[0070]

[0071] As can be seen from the data in Table 1, the sheath layer materials prepared in Examples 3-5 of the present invention have a high limiting oxygen index and good flame retardancy. Among them, in Comparative Example 5, no hyperbranched flame retardant was added, and the measured flame retardancy was significantly lower than that of Examples 3-5.

[0072] (2) Mechanical property test: The sheath layer materials prepared in Examples 3-5 and Comparative Examples 3-5 were subjected to tensile property tests using a universal mechanical testing machine in accordance with GB / T 1040.2-2022, and the change rates of the tensile strength and elongation at break were tested after aging at 110 °C for 168 h. The size of the test specimen was 100 mm × 5 mm × 3.5 mm. The impact strength was tested in accordance with GB / T1843-2008, and the size of the test specimen was 80 mm × 10 mm × 4 mm. The tear strength was tested in accordance with GB / T 529-2008, and the data results are shown in Table 2.

[0073] (3) Heat resistance test: The sheath layer materials prepared in Examples 3-5 and Comparative Examples 3-5 were respectively placed in a TGA-103 thermogravimetric analyzer. Under nitrogen protection, the temperature was raised from room temperature to 800 °C at a heating rate of 5 °C / min, and the initial decomposition temperature of the materials was recorded; the thermal conductivity was tested in accordance with GB / T 3399-1982, and the data results are shown in Table 2.

[0074] Table 2 Test results of the mechanical properties and heat resistance of the samples

[0075]

[0076]

[0077] As can be seen from the data in Table 2, the sheath layer materials prepared in Examples 3-5 of the present invention all have the characteristics of high tensile strength, strong compressive capacity, good heat resistance, and not being easily broken. Among them, in Comparative Example 3, the modified additive component did not graft amino-functionalized graphene oxide and boron nitride nanosheets, and the measured mechanical properties, change rate of tensile strength, change rate of elongation at break, initial decomposition temperature, and thermal conductivity were significantly lower than those in Examples 3-5. In Comparative Example 4, the modified additive component did not graft boron nitride nanosheets, and the measured mechanical properties, initial decomposition temperature, and thermal conductivity were lower than those in Examples 3-5. This shows that adding amino-functionalized graphene oxide grafted with p-phenylenediamine antioxidant can improve the heat-oxygen aging resistance of the material, and graphene oxide and boron nitride nanosheets endow the sheath layer material with excellent mechanical properties and heat resistance to a certain extent.

[0078] In the description of this specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0079] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A pressure-resistant, high-temperature-resistant and easy-to-dissipate heat dissipation new energy vehicle charging cable, characterized in that: The charging cable includes a tape layer, a copper wire braided overall shielding layer, and an outer sheath layer from the inside to the outside. Three power cores, one ground cable core, two signal control cores, and two auxiliary power cores are arranged in the tape layer. The power core includes a conductor and an insulating layer extruded on the outer surface of the conductor. The signal control core is provided with two signal cores. The outer surface of the signal core is sequentially coated with an aluminum-plastic composite tape shielding layer and a copper wire braided shielding layer. The gaps between the tape layer and the three power cores, one ground cable core, two signal control cores, and two auxiliary power cores are filled with a filling layer. The outer sheath layer comprises the following raw materials in parts by weight: 70-90 parts of PVC resin, 20-30 parts of polyurethane thermoplastic elastomer, 10-15 parts of modified additives, 2-5 parts of hyperbranched flame retardant, 5-10 parts of plasticizer, 4-7 parts of stabilizer, and 1-3 parts of lubricant; The modified additive is prepared by grafting ammonium polyphosphate onto silica treated with γ-glycidyloxypropyltrimethoxysilane and then further grafting onto aminated graphene oxide and aminated boron nitride nanosheets; wherein the aminated graphene oxide is prepared by grafting the amino group at one end of the antioxidant p-phenylenediamine with the epoxy group in the graphene oxide structure; and the aminated boron nitride nanosheets are prepared by ball milling using boron nitride and urea as raw materials; The hyperbranched flame retardant is prepared by using DOPO, terephthalaldehyde and 1,5-naphthalenediamine as raw materials to synthesize a DOPO derivative and then using phosphorus oxychloride as a linker to prepare the hyperbranched flame retardant; The preparation method of the hyperbranched flame retardant comprises the following steps: (1) 1,5-naphthalenediamine is placed in a reactor, ethanol solvent is added and mixed evenly, terephthalaldehyde is dissolved in ethanol and added to the reactor, and the mixture is placed at 55-70°C for condensation reflux reaction for 4-6 hours, and then DOPO is dissolved in ethanol and added to the reactor, and the mixture is heated to 75-90°C for reaction for 5-7 hours. After the reaction is completed, the mixture is filtered, washed, and dried to prepare a DOPO derivative; (2) A DOPO derivative, triethylamine and acetonitrile solvent were placed in a reactor, nitrogen was passed through the reactor and the temperature was 0-4°C. An acetonitrile solution containing phosphorus oxychloride was added and the reaction was carried out for 1-2 hours. The mixture was then transferred to an oil bath at 45-60°C and refluxed under nitrogen for 18-24 hours. After the reaction was completed, the mixture was filtered, washed and dried to obtain a hyperbranched flame retardant.

2. The pressure-resistant, high-temperature-resistant and heat-dissipating new energy vehicle charging cable according to claim 1 is characterized in that: The plasticizer is one or more combinations of dioctyl adipate, dimethyl phthalate, dioctyl phthalate, and diisodecyl phthalate; the stabilizer is one of a calcium zinc stabilizer and an organic tin stabilizer; and the lubricant is one of a polyethylene wax and an oxidized polyethylene wax.

3. The pressure-resistant, high-temperature-resistant and heat-dissipating new energy vehicle charging cable according to claim 1, characterized in that: The preparation method of the modified additive comprises the following steps: A. Take ethanol and deionized water in a reactor, place it at 40-50°C and stir for 10-15 minutes, add ammonium polyphosphate, OP-10 and ammonia water and stir to mix, then add tetraethyl orthosilicate and stir to react for 1-2 hours, cool to room temperature after the reaction is completed, filter, wash and dry to prepare silica-coated ammonium polyphosphate; B. Dissolve γ-glycidyloxypropyltrimethoxysilane in a mixed solution of ethanol and deionized water to obtain an ethanol solution containing silane, ultrasonically disperse the silica-coated ammonium polyphosphate in anhydrous ethanol and place it in a reactor, adjust the pH value to 4-5 with dilute hydrochloric acid, then place it at 75-90° C., add the ethanol solution containing silane and stir to react for 5-8 hours, and after the reaction is completed, filter, wash and dry to prepare functionalized silica-coated ammonium polyphosphate; C. Ultrasonic dispersion of graphene oxide in deionized water to obtain a dispersion, dissolving p-phenylenediamine in deionized water and adding the dispersion to the dispersion, ultrasonically mixing and reacting at 30-50° C. for 18-24 h, filtering, washing and drying after the reaction to obtain amino-modified graphene oxide; D. Put the amino-modified graphene oxide and the functionalized silica-coated ammonium polyphosphate in a reactor, add deionized water for ultrasonic dispersion, place at 35-50° C. for reaction for 18-24 hours, filter, wash and dry after the reaction is completed to prepare a composite filler; E. Take the composite filler and ultrasonically disperse it in deionized water, add amino boron nitride nanosheets and stir to mix, adjust the pH value of the system to 7-9 with a sodium carbonate solution with a mass fraction of 10-20%, then add carbodiimide and N-hydroxysuccinimide, stir to react for 3-5 hours, and after the reaction is completed, filter and dry to prepare the modified additive.

4. The pressure-resistant, high-temperature-resistant and heat-dissipating new energy vehicle charging cable according to claim 3 is characterized in that: In the step D, the mass ratio of the aminated graphene oxide to the functionalized silica-coated ammonium polyphosphate is 1-3:

1.

5. The pressure-resistant, high-temperature-resistant and heat-dissipating new energy vehicle charging cable according to claim 3 is characterized in that: In the step E, the mass ratio of the composite filler to the amino boron nitride nanosheets is 0.75-1.2:

1.

6. The pressure-resistant, high-temperature-resistant and heat-dissipating new energy vehicle charging cable according to claim 3, characterized in that: The preparation method of the amination boron nitride nanosheet in step E comprises the following steps: putting boron nitride and urea in a ball mill, adding deionized water and steel balls for ball milling, centrifuging the reaction solution at 950-1100 r / min for 10-20 min after the ball milling, collecting the upper suspension and continuing to centrifuge at 4500-5000 r / min for 30-40 min, taking the lower precipitate and drying it to prepare the amination boron nitride nanosheet.

7. The pressure-resistant, high-temperature-resistant and heat-dissipating new energy vehicle charging cable according to claim 6, characterized in that: The steel balls are 2 mm, 5 mm and 10 mm in diameter, which are mixed and added in a ratio of 4:2:

1. The rotation speed of the ball mill is 750-900 r / min, and the ball milling time is 7-10 h.

8. The pressure-resistant, high-temperature-resistant and heat-dissipating new energy vehicle charging cable according to claim 1, characterized in that: In the step (2), the molar ratio of the DOPO derivative to phosphorus oxychloride is 1.5:1-1.

2.

9. The pressure-resistant, high-temperature-resistant and heat-dissipating new energy vehicle charging cable according to claim 1, characterized in that: The preparation method of the outer sheath layer material comprises the following steps: S1. Weigh each raw material by weight, take PVC resin, plasticizer and stabilizer and stir and mix them in a mixer, set the mixer temperature to 60-80°C, then add modifying additives, hyperbranched flame retardant and lubricant and continue to stir and mix, at this time, set the mixer temperature to 100-120°C, mix and extrude granulate to obtain masterbatch; S2. Mix the masterbatch material and parts by weight of the polyurethane elastomer, put them into a twin-screw extruder for extrusion molding, and prepare an outer sheath layer material.

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