High-temperature-resistant long-service-life cable material for charging pile cable and preparation method thereof

Abstract

The application discloses a kind of high-temperature-resistant long-life cable material for charging pile cable and a preparation method thereof, and relates to the field of cable material.The cable material includes ethylene-propylene rubber, acrylate rubber, a compatibilizer, stearic acid, zinc oxide, paraffin oil, a vulcanizing agent, a vulcanization aid, nano filler supported antioxidant, and reinforcing filler.The application uses acrylate rubber and ethylene-propylene rubber blending to improve material plasticity and temperature resistance grade, and uses nano filler with reinforcing effect to disperse uniformly and stably in rubber matrix and has the characteristics of improving mechanical properties.The antioxidant is loaded on the nano filler to avoid surface migration of the antioxidant at high temperature, which significantly improves the high-temperature resistance and mechanical properties of the cable material, and can meet the challenges of cable material performance caused by the gradual shortening of charging time and the increasing of charging current of charging pile.

Description

Technical Field

[0001] This invention relates to the field of cable materials, and in particular to a high-temperature resistant, long-life cable material for charging pile cables and its preparation method. Background Technology

[0002] With the rapid development of new energy electric vehicles, the market is placing increasingly higher demands on charging time. Gradually shortening charging time to be comparable to refueling time for gasoline vehicles, and improving the user experience, is one of the hot research topics for the future. Currently, the main method to improve charging time is to increase the charging current. However, a large current during charging can lead to excessively high temperatures in the charging pile cables. Prolonged exposure to high temperatures puts a strain on the cable material's performance and can significantly impact the cable's lifespan.

[0003] To enable charging pile cables to meet the challenges posed by rapidly increasing charging times, the cable materials used need to possess high-temperature resistance and long service life. Since the main components of these materials are mostly polymers such as polyolefins, polyurethane, and ethylene propylene rubber, even high-temperature resistant ethylene propylene rubber can only be used for short periods at 150°C. Prolonged exposure to high temperatures will significantly shorten the cable's lifespan. Furthermore, most common antioxidants added to these materials tend to migrate to the surface of the product when heated, negatively impacting their resistance to thermo-oxidative aging and greatly reducing their lifespan, thus limiting their application in charging pile cables. Summary of the Invention

[0004] This invention provides a high-temperature resistant, long-life cable material for charging pile cables and its preparation method, in order to solve the problems of low temperature resistance and short service life at high temperatures in current cable materials, improve the resistance to thermo-oxidative aging of cable materials, and extend the service life under high-temperature operating environments.

[0005] To address the aforementioned technical problems, one objective of this invention is to provide a high-temperature resistant, long-life cable material for charging pile cables, comprising the following components in parts by weight:

[0006] Ethylene-propylene rubber: 70-90 parts;

[0007] Acrylic rubber: 10-30 parts;

[0008] Compatibilizer: 5-20 parts;

[0009] Stearic acid: 1-2 parts;

[0010] Zinc oxide: 5-10 parts;

[0011] Paraffin oil: 10-30 parts;

[0012] Vulcanizing agent: 2-5 parts;

[0013] Vulcanizing agent: 1-3 parts;

[0014] Nanofiller-supported antioxidant: 2-5 parts;

[0015] Reinforcing filler: 20-55 parts.

[0016] By adopting the above-mentioned scheme, this application uses a blend of acrylic rubber and ethylene propylene rubber, which can improve the physical properties of the cable material itself, increase the plasticity of the material, and the blended rubber matrix has higher high-temperature resistance, improving the temperature resistance level. This can increase the service life of the cable material in high-temperature operating environments and improve the resistance to thermal oxidation. Due to the uniform and stable dispersion of nanomaterials in the rubber matrix, the antioxidant is firmly loaded onto the nanomaterials. This can not only utilize nanofillers to improve the reinforcement effect of the cable material, but also avoid the surface migration of the antioxidant at high temperatures. Furthermore, the nanomaterials loaded onto the antioxidant can further enhance the antioxidant's resistance to thermal and oxygen aging. Overall, this significantly improves the high-temperature resistance and high-temperature service life of the cable material, enabling it to meet the challenges to cable material performance brought about by the gradual shortening of charging time and the increasing charging current of charging piles.

[0017] As a preferred embodiment, the nanomaterials in the nanofiller-supported antioxidant are loaded onto the antioxidant using a silane coupling agent. The nanofiller is at least one of nano-silica, nano-silica, nano-carbon black, nano-zinc oxide, and nano-calcium carbonate. The antioxidant is at least one of 2,2,4-trimethyl-1,2-dihydroquinoline, N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1-methylisopentyl)-N'-phenyl-p-phenylenediamine, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2-mercaptobenzimidazole, and 4,4-bis(phenylisopropyl)diphenylamine. The silane coupling agent is at least one of γ-aminopropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-(methacryloyldeoxy)propyltrimethoxysilane.

[0018] As a preferred embodiment, the preparation method of the nanofiller-supported antioxidant includes the following steps:

[0019] (1) The nanofiller is dispersed in an organic solvent and ultrasonically dispersed to obtain a suspension. Then, a silane coupling agent is added to the suspension, stirred at 70-90℃ for 3-6 hours, filtered, and washed to obtain pretreated nanomaterials.

[0020] (2) Take the pretreated nanofiller and antioxidant and add them to an organic solvent. Stir at 70-90℃ for 6-10 hours, wash and dry to obtain nanofiller loaded antioxidant.

[0021] By adopting the above scheme, the nanofiller is stably loaded onto the surface of the antioxidant through the silane coupling agent. Its bonding strength can overcome the high-temperature migration force of the antioxidant in the rubber matrix, so that the antioxidant is stably and uniformly dispersed in the blended rubber matrix. It works synergistically with the acrylic rubber to improve the resistance of cable material to thermo-oxidative aging and extend its service life.

[0022] As a preferred embodiment, the nanofiller in the nanofiller-loaded antioxidant has a particle size of 50-70 nm.

[0023] As a preferred embodiment, the ethylene propylene rubber is a binary ethylene propylene rubber, or a ternary ethylene propylene rubber with the third monomer being ethylidene norbornene, ethyl norbornene, dicyclopentadiene, 1,4-hexadiene, or a combination thereof.

[0024] The acrylate rubber is at least one of the following: non-chlorinated polyamine crosslinking type, self-crosslinking type, carboxylic acid ammonium salt crosslinking type, and soap crosslinking type.

[0025] As a preferred embodiment, the compatibilizer is at least one of EPDM-grafted maleic anhydride, EPDM-grafted maleic anhydride, EPDM-grafted silane coupling agent, and EPDM-grafted silane coupling agent.

[0026] By adopting the above scheme, the blended rubber matrix of this application is mainly composed of ethylene propylene rubber. Therefore, ethylene propylene rubber grafted silane coupling agent or maleic anhydride is selected as the preferred compatibilizer. The bonding force between the ethylene propylene rubber and the molecules in the matrix is ​​high, which can promote the cross-linking of ethylene propylene rubber and acrylic rubber to form a multidimensional network structure, improve the overall toughness and structural stability, improve the temperature resistance, and extend the service life under high temperature conditions.

[0027] As a preferred embodiment, the vulcanizing agent is at least one of bis-tert-butylperoxyisopropylbenzene, diisopropylbenzene peroxide, hexamethylenediamine carbamate, trithiocyanate, trihexylidenetetramine, and tetrahexylidenepentamine.

[0028] As a preferred embodiment, the vulcanizing agent is at least one of triallyl isocyanurate, N,N-m-phenylene bismaleimide, divinylbenzene, trialkyl cyanurate, and zinc dibutyl dithiocarbamate (II).

[0029] As a preferred embodiment, the reinforcing filler is at least one of kaolin, talc, calcium carbonate, and silica.

[0030] To address the aforementioned technical problems, a second objective of this invention is to provide a method for preparing high-temperature resistant, long-life cable material for charging pile cables, comprising the following steps:

[0031] (1) Add acrylic rubber, 10wt%-30wt% paraffin oil, 10wt%-30wt% reinforcing filler, 10wt%-30wt% nano filler loaded with antioxidant to a mixing equipment, mix and discharge to obtain acrylic rubber masterbatch;

[0032] (2) Add EPDM rubber, stearic acid, zinc oxide, residual paraffin oil, residual silica, and residual nanofiller loaded with antioxidant to another internal mixing equipment, and after mixing, obtain EPDM rubber masterbatch;

[0033] (3) Add the acrylate rubber masterbatch, EPDM rubber masterbatch and compatibilizer to the internal mixer for mixing. After mixing for 1-3 minutes, add the vulcanizing agent and vulcanizing aid, mix and discharge to obtain EPDM / acrylate rubber blend.

[0034] (4) The above-mentioned blended material is put into a granulation equipment and extruded into granules to obtain high temperature resistant and long life cable material for charging pile cables.

[0035] As a preferred option, in step (1), the temperature of the mixing equipment is set to 40-60℃ and the rotation speed is 60-100rpm before feeding.

[0036] As a preferred option, in step (2), the temperature of the internal mixer is kept at 70-90℃ and the rotation speed is 60-100rpm before feeding.

[0037] As a preferred option, in step (3), the mixing temperature is 70-90℃ and the rotation speed is 60-100rpm.

[0038] As a preferred embodiment, in step (4), the granulation temperature is 50-60 ℃, the feeding frequency is 20-30 Hz, the screw frequency is 20-30 Hz, and the pelletizing frequency is 6-8 Hz.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. This application uses a blend of acrylic rubber and ethylene propylene rubber, which can improve the physical properties of the cable material, increase the plasticity of the material, and the blended rubber matrix has higher high temperature resistance, thereby improving the service life of the cable material in high temperature operating environments and enhancing the heat oxidation resistance.

[0041] 2. Due to the uniform and stable dispersion of nanofillers in the rubber matrix, the antioxidant is firmly loaded onto the nanofillers. This not only enhances the reinforcing effect of the cable material by utilizing the nanofillers, but also prevents the antioxidant from migrating to the surface at high temperatures, thus significantly improving the high-temperature resistance and service life of the cable material.

[0042] 3. The blended rubber matrix of this application is mainly composed of ethylene propylene rubber. Silane grafting agents or maleic anhydride grafting agents are preferred as compatibilizers. These agents have high bonding forces with the molecules of ethylene propylene rubber in the matrix, which can promote the cross-linking of ethylene propylene rubber and acrylic rubber to form a multidimensional network structure, improving the overall toughness, strength, and structural stability of the rubber, and also increasing its temperature resistance and extending its service life under high-temperature conditions. Detailed Implementation

[0043] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] Table 1 - Sources of raw materials used in the embodiments and comparative examples of this application

[0045]

[0046] Preparation Example 1

[0047] A nanofiller-supported rubber antioxidant, wherein the nanofiller is nano-silica and the supported antioxidant is 2-mercaptobenzimidazole, is prepared by the following steps:

[0048] (1) 20g of nano silica (particle size of 60nm) was dispersed in 550 ml of anhydrous ethanol and ultrasonically dispersed at room temperature for 15 min to obtain a suspension. Then 4g of silane coupling agent A-174 was added to the suspension, stirred at 80 ℃ for 5 h, filtered, and washed with anhydrous ethanol to obtain pretreated nano silica.

[0049] (2) Take 10g of pretreated nano silica and 2g of 2-mercaptobenzimidazole and add them to 300 ml of anhydrous ethanol solution. Stir at 80 °C for 8 h. Wash the obtained product with anhydrous ethanol and place it in a vacuum oven. Dry at 60 °C for 24 h to obtain nano silica-supported 2-mercaptobenzimidazole.

[0050] Preparation Example 2

[0051] A nanofiller-supported rubber antioxidant, wherein the nanofiller is nano-silica and the supported antioxidant is 2-mercaptobenzimidazole, comprises the following preparation steps:

[0052] (1) 20g of nano silica was dispersed in 550 ml of anhydrous ethanol and ultrasonically dispersed at room temperature for 15 min to obtain a suspension. Then 4g of silane coupling agent A-174 was added to the suspension, stirred at 80 °C for 5 h, filtered, and washed with anhydrous ethanol to obtain pretreated nano silica.

[0053] (2) Take 10g of pretreated nano silica and 2g of 2,2,4-trimethyl-1,2-dihydroquinoline and add them to 300 ml of anhydrous ethanol solution. Stir at 80 °C for 8 h. Wash the product with anhydrous ethanol and place it in a vacuum oven. Dry at 60 °C for 24 h to obtain nano silica-supported 2,2,4-trimethyl-1,2-dihydroquinoline.

[0054] Preparation Example 3

[0055] A EPDM rubber grafted silane coupling agent, the preparation method of which includes the following steps:

[0056] 100g of EPDM rubber, 8g of KH550 silane coupling agent, and 1g of dicumyl peroxide were added to a two-roll mill and pre-mixed at 45°C for 7 minutes. Then, the mixture was placed in a Hacker torque rheometer with the rotor speed set at 70 rpm and hot-mixed at 180°C for 5 minutes to obtain EPDM rubber grafted with silane coupling agent (EPDM-gS).

[0057] Example 1

[0058] A high-temperature resistant, long-life cable material for charging pile cables includes acrylate rubber, EPDM rubber, paraffin oil, silica, 2-mercaptobenzimidazole supported on nano-silica (Preparation Example 1), 2,2,4-trimethyl-1,2-dihydroquinoline supported on nano-silica (Preparation Example 2), stearic acid, zinc oxide, EPDM rubber grafted with silane coupling agent (Preparation Example 3), dicumyl peroxide, trithiocyanate, triallyl isocyanurate, and zinc dibutyl dithiocarbamate (II). The silica has a particle size of 50 nm, and the zinc oxide has a particle size of 60 nm. The preparation method includes the following steps:

[0059] (1) Set the internal mixer temperature to 50 ℃ and the rotation speed to 80 rpm. After the temperature stabilizes, add 10 kg of acrylic rubber, 2 kg of paraffin oil, 5 kg of carbon black, 0.375 kg of nano silica-supported 2-mercaptobenzimidazole and 0.125 kg of nano silica-supported 2,2,4-trimethyl-1,2-dihydroquinoline. Mix for 3 min and then discharge to obtain acrylic rubber masterbatch.

[0060] (2) Raise the temperature of the internal mixer to 80 ℃ and the rotation speed to 80 rpm. After the temperature stabilizes, add 90 kg of EPDM rubber, 1 kg of stearic acid, 5 kg of zinc oxide, 18 kg of paraffin oil, 45 kg of silica, 3.375 kg of nano silica-supported 2-mercaptobenzimidazole and 1.125 kg of nano silica-supported 2,2,4-trimethyl-1,2-dihydroquinoline. Mix for 5 min to obtain EPDM rubber masterbatch.

[0061] (3) Add all the above-mentioned acrylic rubber masterbatch, EPDM rubber masterbatch, and 5 kg of EPDM rubber grafted silane coupling agent to a mixer for blending. The mixing temperature is 80 ℃ and the speed is 80 rpm. After mixing for 2 min, add 3.6 kg of dicumyl peroxide, 0.4 kg of trithiocyanate, 1 kg of triallyl isocyanurate, and 0.5 kg of zinc dibutyl dithiocarbamate (II). After mixing for 3 min, discharge the material to obtain EPDM rubber / acrylate rubber blend.

[0062] (4) The above-mentioned blended material is fed into a granulator. The granulation temperature is 60 ℃, the feeding frequency is 25 Hz, the screw frequency is 25 Hz, and the pelletizing frequency is 7 Hz. After being extruded into granules, high-temperature resistant and long-life cable material for charging pile cables is obtained.

[0063] Example 2

[0064] A high-temperature resistant, long-life cable material for charging pile cables includes acrylate rubber, EPDM rubber, paraffin oil, silica, 2-mercaptobenzimidazole supported on nano-silica (Preparation Example 1), 2,2,4-trimethyl-1,2-dihydroquinoline supported on nano-silica (Preparation Example 2), stearic acid, zinc oxide, EPDM rubber grafted with silane coupling agent (Preparation Example 3), dicumyl peroxide, trithiocyanate, triallyl isocyanurate, and zinc dibutyl dithiocarbamate (II). The silica has a particle size of 50 nm, and the zinc oxide has a particle size of 60 nm. The preparation method includes the following steps:

[0065] (1) Set the internal mixer temperature to 50 ℃ and the rotation speed to 80 rpm. After the temperature stabilizes, add 20 kg of acrylic rubber, 4 kg of paraffin oil, 10 kg of carbon black, 0.75 kg of nano silica-supported 2-mercaptobenzimidazole and 0.25 kg of nano silica-supported 2,2,4-trimethyl-1,2-dihydroquinoline. Mix for 3 min and then discharge to obtain acrylic rubber masterbatch.

[0066] (2) Raise the temperature of the internal mixer to 80 ℃ and the speed to 80 rpm. After the temperature stabilizes, add 80 kg of EPDM rubber, 1 kg of stearic acid, 5 kg of zinc oxide, 16 kg of paraffin oil, 40 kg of silica, 3 kg of nano-silica-supported 2-mercaptobenzimidazole and 1 kg of nano-silica-supported 2,2,4-trimethyl-1,2-dihydroquinoline. Mix for 5 min to obtain EPDM rubber masterbatch.

[0067] (3) Add all the above-mentioned acrylate rubber masterbatch, EPDM rubber masterbatch, and 10 kg of EPDM rubber grafted silane coupling agent to a mixer for blending. The mixing temperature is 80 ℃ and the speed is 80 rpm. After mixing for 2 min, add 3.2 kg of dicumyl peroxide, 0.8 kg of trithiocyanate, 1 kg of triallyl isocyanurate, and 0.5 kg of zinc dibutyl dithiocarbamate (II). After mixing for 3 min, discharge the material to obtain EPDM rubber / acrylate rubber blend.

[0068] (4) The above-mentioned blended material is fed into a granulator. The granulation temperature is 60 ℃, the feeding frequency is 25 Hz, the screw frequency is 25 Hz, and the pelletizing frequency is 7 Hz. After being extruded into granules, high-temperature resistant and long-life cable material for charging pile cables is obtained.

[0069] Example 3

[0070] A high-temperature resistant, long-life cable material for charging pile cables includes acrylate rubber, EPDM rubber, paraffin oil, silica, 2-mercaptobenzimidazole supported on nano-silica (Preparation Example 1), 2,2,4-trimethyl-1,2-dihydroquinoline supported on nano-silica (Preparation Example 2), stearic acid, zinc oxide, EPDM rubber grafted with silane coupling agent (Preparation Example 3), dicumyl peroxide, trithiocyanate, triallyl isocyanurate, and zinc dibutyl dithiocarbamate (II). The silica has a particle size of 50 nm, and the zinc oxide has a particle size of 60 nm. The preparation method includes the following steps:

[0071] (1) Set the internal mixer temperature to 50 ℃ and the rotation speed to 80 rpm. After the temperature stabilizes, add 25 kg of acrylate rubber, 6 kg of paraffin oil, 15 kg of carbon black, 1.125 kg of nano silica-supported 2-mercaptobenzimidazole and 0.375 kg of nano silica-supported 2,2,4-trimethyl-1,2-dihydroquinoline. Mix for 3 min and then discharge to obtain acrylate rubber masterbatch.

[0072] (2) Raise the temperature of the internal mixer to 80 ℃ and the rotation speed to 80 rpm. After the temperature stabilizes, add 75 kg of EPDM rubber, 1 kg of stearic acid, 5 kg of zinc oxide, 14 kg of paraffin oil, 35 kg of silica, 2.625 kg of nano silica-supported 2-mercaptobenzimidazole and 0.875 kg of nano silica-supported 2,2,4-trimethyl-1,2-dihydroquinoline. Mix for 5 min to obtain EPDM rubber masterbatch.

[0073] (3) Add all the above-mentioned acrylate rubber masterbatch, EPDM rubber masterbatch, and 15 kg of EPDM rubber grafted silane coupling agent to a mixer for blending. The mixing temperature is 80 ℃ and the speed is 80 rpm. After mixing for 2 min, add 3 kg of dicumyl peroxide, 1 kg of trithiocyanate, 1 kg of triallyl isocyanurate, and 0.5 kg of zinc dibutyl dithiocarbamate (II). After mixing for 3 min, discharge the material to obtain EPDM rubber / acrylate rubber blend.

[0074] (4) The above-mentioned blended material is fed into a granulator. The granulation temperature is 60 ℃, the feeding frequency is 25 Hz, the screw frequency is 25 Hz, and the pelletizing frequency is 7 Hz. After being extruded into granules, high-temperature resistant and long-life cable material for charging pile cables is obtained.

[0075] Example 4

[0076] A high-temperature resistant, long-life cable material for charging pile cables is prepared in the same way as Example 3, with each step and the reagents and process parameters used in each step being the same. The difference is that the nano-silica-supported 2-mercaptobenzimidazole in Example 1 is replaced by an equal amount of nano-silica-supported 2,2,4-trimethyl-1,2-dihydroquinoline in Example 2.

[0077] Example 5

[0078] A high-temperature resistant, long-life cable material for charging pile cables is prepared in the same way as Example 3, with each step and reagent and process parameter being the same. The difference is that the EPDM rubber grafted silane coupling agent in Example 3 is replaced by an equal amount of maleic anhydride grafted EPDM rubber.

[0079] Comparative Example 1

[0080] A cable material for charging pile cables includes EPDM rubber, paraffin oil, silica, 2-mercaptobenzimidazole supported on nano-silica (Preparation Example 1), 2,2,4-trimethyl-1,2-dihydroquinoline supported on nano-silica (Preparation Example 2), stearic acid, zinc oxide, EPDM rubber grafted with silane coupling agent (Preparation Example 3), dicumyl peroxide, trithiocyanate, triallyl isocyanurate, and zinc dibutyl dithiocarbamate (II). The silica has a particle size of 50 nm, and the zinc oxide has a particle size of 60 nm. The preparation method includes the following steps:

[0081] (1) Raise the temperature of the internal mixer to 80 ℃ and the rotation speed to 80 rpm. After the temperature stabilizes, add 100 kg of EPDM rubber, 1 kg of stearic acid, 5 kg of zinc oxide, 20 kg of paraffin oil, 50 kg of silica, 3.75 kg of nano silica-supported 2-mercaptobenzimidazole and 1.25 kg of nano silica-supported 2,2,4-trimethyl-1,2-dihydroquinoline. Mix for 5 min to obtain EPDM rubber masterbatch.

[0082] (2) Add all of the above EPDM masterbatch and 15 kg of EPDM grafted silane coupling agent to a mixer for blending. The mixing temperature is 80 ℃ and the speed is 80 rpm. After mixing for 2 min, add 3 kg of dicumyl peroxide, 1 kg of trithiocyanate, 1 kg of triallyl isocyanurate and 0.5 kg of zinc dibutyl dithiocarbamate (II). After mixing for 3 min, discharge the material to obtain EPDM blend.

[0083] (3) The above-mentioned blended material is fed into a granulator. The granulation temperature is 60 ℃, the feeding frequency is 25 Hz, the screw frequency is 25 Hz, and the pelletizing frequency is 7 Hz. After being extruded into granules, the cable material for charging pile cables is obtained.

[0084] Comparative Example 2

[0085] A high-temperature resistant, long-life cable material for charging pile cables is prepared in the same way as Example 3, with each step and reagent and process parameter being the same. The difference is that in Example 1, 2-mercaptobenzimidazole loaded with nano-silica is replaced by an equal amount of 2-mercaptobenzimidazole, and in Example 2, 2,2,4-trimethyl-1,2-dihydroquinoline loaded with nano-silica is replaced by an equal amount of 2,2,4-trimethyl-1,2-dihydroquinoline.

[0086] Comparative Example 3

[0087] A high-temperature resistant, long-life cable material for charging pile cables is prepared in the same way as that in Example 3, except that the amount of paraffin oil added is 0.

[0088] Comparative Example 4

[0089] A high-temperature resistant, long-life cable material for charging pile cables is prepared in the same way as Example 3, with the same steps, reagents, and process parameters. The difference is that the amount of EPDM-grafted silane coupling agent added in Example 3 is 0.

[0090] Performance testing

[0091] 1. The tensile strength and elongation at break of the cable material samples prepared in the examples and comparative examples were tested according to GB / T 528-2009 standard. The test samples were prepared by hot pressing at 180℃ for 10 min using a flat vulcanizing machine. The sample size was 5cm×5cm×1cm. The test results are shown in Table 2 below.

[0092] 2. The insulation resistance constant of the cable material samples prepared in the examples and comparative examples was tested according to GB / T 33594-2017 standard. The sample size was 5cm×5cm×1cm. The test samples were prepared by hot pressing at 180℃ for 10min using a flat vulcanizing machine. The test temperature was 20℃. The test results are shown in Table 2 below.

[0093] 3. The cable material samples prepared in the examples and comparative examples were subjected to thermo-oxidative aging tests in accordance with GB / T 2951.12-2008 standard. The test samples were prepared by hot pressing at 180℃ for 10 min using a flat vulcanizing machine. After 168 h at 165℃, the change rate of tensile strength and the change rate of elongation at break of the cable material were tested. The test results are shown in Table 2 below.

[0094] 4. The cable material samples prepared in the examples and comparative examples were subjected to thermal elongation tests in accordance with GB / T 2951.21-2008 standard. The test samples were prepared by hot pressing at 180℃ for 10 min using a flat vulcanizing machine. The sample size was 5cm×5cm×1cm. The test temperature was 250℃ and the test time was 15 min. The maximum elongation under the test load and the permanent elongation after cooling were tested. The test results are shown in Table 2 below.

[0095] 5. According to GB / T 2951.21-2008 standard, cable material samples prepared in the examples and comparative examples were subjected to ozone resistance tests. Test samples were prepared by hot pressing at 180℃ for 10 min using a flat vulcanizing machine. The sample size was 5cm×5cm×1cm. The test conditions were ozone concentration of 0.03%, temperature of 25℃, and time of 24 h. The samples were observed to see if they cracked. The test results are shown in Table 2 below.

[0096] Table 2 - Performance test results of cable material products prepared in the embodiments and comparative examples of this application

[0097]

[0098] Comparing the performance test results of Example 3 and Comparative Examples 1-2 in Table 2, it can be seen that the blending of acrylate rubber and EPDM rubber in this application can improve the overall high-temperature resistance. The use of EPDM rubber grafted with silane coupling agent promotes the compatibility of the acrylate rubber and EPDM rubber matrix, improving the physical properties of the cable material itself, resulting in higher plasticity and significantly enhanced high-temperature resistance. Furthermore, due to the inherent properties of nanomaterials, the nanomaterial-loaded antioxidant exhibits high stability in the cable material, is less prone to migration to the material surface, and disperses more evenly, even acting as a reinforcing agent. This prevents excessive local aging of the material and balances its resistance to thermo-oxidative aging. After operating at 165°C for 168 hours, its tensile strength increased by only about 19%, and its elongation decreased by only about 16%. Compared to Comparative Examples 1-2, Example 3 demonstrates improved thermo-oxidative aging resistance and a longer service life.

[0099] Comparing the performance test results of Examples 3 and 5 and Comparative Example 4 in Table 2, it can be seen that, compared with Comparative Example 4, Example 6, which adds maleic anhydride-grafted EPDM rubber, produces cable material with higher plasticity and high-temperature aging resistance. Compared with Example 5, the EPDM rubber grafted with maleic anhydride in Example 3 of this application, through the grafting of more EPDM rubber, can effectively promote the compatibility between acrylate rubber and EPDM rubber matrix, and while having high-temperature aging resistance, further improves the plasticity of the cable material.

[0100] Comparing the performance test results of Example 3 and Comparative Examples 2-3 in Table 2, it can be seen that the antioxidants in Comparative Example 2 are 2-mercaptobenzimidazole and 2,2,4-trimethyl-1,2-dihydroquinoline, while Comparative Example 3 did not add paraffin oil. The resulting cable materials have low resistance to thermo-oxidative aging. In a thermo-oxidative environment, the cable materials undergo oxidative hardening, resulting in increased hardness and decreased plasticity. Example 3 of this application, by simultaneously adding nanomaterial-loaded antioxidants and paraffin oil, can not only improve the original toughness of the cable material, but also improve its resistance to thermo-oxidative aging, thus meeting application requirements.

[0101] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A high-temperature resistant, long-life cable material for charging pile cables, characterized in that, The components include the following parts by weight: Ethylene-propylene rubber: 70-90 parts; Acrylic rubber: 10-30 parts; Compatibilizer: 5-20 parts; Stearic acid: 1-2 parts; Zinc oxide: 5-10 parts; Paraffin oil: 10-30 parts; Vulcanizing agent: 2-5 parts; Vulcanizing agent: 1-3 parts; Nanofiller-supported antioxidant: 2-5 parts; Reinforcing filler: 20-55 parts; The nanofiller in the nanofiller-supported antioxidant is a silane coupling agent loaded onto the antioxidant. The nanofiller is at least one of nano-silica, nano-carbon black, nano-zinc oxide, and nano-calcium carbonate. The antioxidant is at least one of 2,2,4-trimethyl-1,2-dihydroquinoline, N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1-methylisopentyl)-N'-phenyl-p-phenylenediamine, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2-mercaptobenzimidazole, and 4,4-di(phenylisopropyl)diphenylamine. The silane coupling agent is at least one of γ-aminopropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-(methacryloyldeoxy)propyltrimethoxysilane. The preparation method of the nanofiller-supported antioxidant includes the following steps: (1) The nanofiller is dispersed in an organic solvent and ultrasonically dispersed to obtain a suspension. Then, a silane coupling agent is added to the suspension, stirred at 70-90℃ for 3-6 hours, filtered, and washed to obtain pretreated nanomaterials. (2) Take the pretreated nanofiller and antioxidant and add them to an organic solvent. Stir at 70-90℃ for 6-10 hours, wash and dry to obtain nanofiller loaded antioxidant.

2. The high-temperature resistant, long-life cable material for charging pile cables as described in claim 1, characterized in that, The ethylene propylene rubber is a binary ethylene propylene rubber, or a ternary ethylene propylene rubber with the third monomer being ethylidene norbornene, ethyl norbornene, dicyclopentadiene, 1,4-hexadiene, or a combination thereof. The acrylate rubber is at least one of the following: non-chlorinated polyamine crosslinking type, self-crosslinking type, carboxylic acid ammonium salt crosslinking type, and soap crosslinking type.

3. The high-temperature resistant, long-life cable material for charging pile cables as described in claim 1, characterized in that, The compatibilizer is at least one of the following: EPDM-grafted maleic anhydride, EPDM-grafted maleic anhydride, EPDM-grafted silane coupling agent, and EPDM-grafted silane coupling agent.

4. The high-temperature resistant, long-life cable material for charging pile cables as described in claim 1, characterized in that, The vulcanizing agent is at least one of bis-tert-butylperoxyisopropylbenzene, diisopropylbenzene peroxide, hexamethylenediamine carbamate, trithiocyanate, trihexylexyltetramine, and tetrahexylexylpentamine.

5. The high-temperature resistant, long-life cable material for charging pile cables as described in claim 1, characterized in that, The co-vulcanizing agent is at least one of triallyl isocyanurate, N,N-m-phenylene bismaleimide, divinylbenzene, trialkyl cyanurate, and zinc dibutyl dithiocarbamate (II).

6. The high-temperature resistant, long-life cable material for charging pile cables as described in claim 1, characterized in that, The reinforcing filler is at least one of kaolin, talc, calcium carbonate, and silica.

7. A method for preparing high-temperature resistant, long-life cable material for charging pile cables as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) Add acrylic rubber, 10wt%-30wt% paraffin oil, 10wt%-30wt% reinforcing filler, 10wt%-30wt% nano filler loaded with antioxidant to a mixing equipment, mix and discharge to obtain acrylic rubber masterbatch; (2) Add EPDM rubber, stearic acid, zinc oxide, remaining paraffin oil, remaining reinforcing filler, and remaining nanofiller loaded with antioxidant to another internal mixing equipment, and after mixing, obtain EPDM rubber masterbatch; (3) Add the acrylate rubber masterbatch, EPDM rubber masterbatch and compatibilizer to the internal mixer for mixing. After mixing for 1-3 minutes, add the vulcanizing agent and vulcanizing aid, mix and discharge to obtain EPDM / acrylate rubber blend. (4) The above-mentioned blended material is put into a granulation equipment and extruded into granules to obtain high temperature resistant and long life cable material for charging pile cables.

8. The method for preparing a high-temperature resistant, long-life cable material for charging pile cables as described in claim 7, characterized in that, Satisfying at least one of the following a)-d): a) In step (1), before adding materials, the temperature of the mixing equipment is set to 40-60℃ and the rotation speed is 60-100rpm; b) In step (2), before adding materials, maintain the temperature of the mixing equipment at 70-90℃ and the rotation speed at 60-100rpm; c) In step (3), the mixing temperature is 70-90℃ and the rotation speed is 60-100rpm; d) In step (4), the granulation temperature is 50-60 ℃, the feeding frequency is 20-30 Hz, the screw frequency is 20-30 Hz, and the pelletizing frequency is 6-8 Hz.

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