TPE (thermoplastic elastomer) sheath material for charging cable and preparation method of TPE sheath material

Abstract

The invention relates to the technical field of preparation of charging cables of new energy automobiles, in particular to a TPE sheath material for a charging cable and a preparation method. The TPE sheath material for the charging cable is characterized by comprising the following raw materials in percentage by mass: 15%-20% of polypropylene, 10%-15% of ethylene propylene diene monomer, 40%-50% of hydrogenated styrene-ethylene-butadiene-styrene copolymer, 9%-14% of naphthenic oil, 5%-10% of polyolefin elastomer, 1%-3% of black masterbatch, 0.5%-2% of tetraethylenepentamine, 1%-3% of chitosan and 2%-5% of lignin. The TPE sheath material disclosed by the invention has good mechanical property, wear resistance and flame retardant property.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of charging cables for new energy vehicles, and in particular to a TPE sheath material for a charging cable and a preparation method thereof. Background Art

[0002] With the rapid development of the new energy vehicle industry, the demand for efficient, safe and reliable charging facilities is increasing. As an indispensable key component connecting electric vehicles and charging piles, charging cables must not only be able to cope with frequent plug-in and unplug operations, but also be able to withstand the influence of complex and changeable outdoor environments, and must have a series of important physical and chemical properties. These properties include but are not limited to good mechanical properties, electrical insulation properties, good weather resistance and flame retardancy. At present, in the market, there are various choices of materials for charging cable sheath materials, and the common ones are polyvinyl chloride (PVC), polyethylene (PE), thermoplastic polyurethane (TPU) or thermoplastic elastomer (TPE). Among these materials, thermoplastic elastomer TPE has shown significant advantages and broad application prospects in the application field of charging cable sheath materials due to its good flexibility and resilience, processing convenience and good chemical corrosion resistance.

[0003] However, since TPE is essentially a soft polymer, its surface hardness is relatively low and it is susceptible to wear. Especially in frequently used charging scenarios, such as public parking lots or roadside charging stations, the cable sheath material may cause surface damage due to factors such as dragging and rolling, thereby affecting the overall service life of the cable. In view of this, in order to better meet the actual needs of new energy vehicle charging cables, it is necessary to further optimize the existing TPE materials and further improve the wear resistance of TPE materials. Summary of the invention

[0004] In order to further improve the wear resistance of TPE materials, the present application provides a TPE sheath material for charging cables and a preparation method. The TPE sheath material for charging cables and the preparation method thereof provided in the present application can significantly improve the mechanical properties, wear resistance and flame retardancy of the TPE sheath material by selecting a specific combination of raw materials and preparation process, and provide a high-quality material selection for the manufacture of new energy vehicle charging cables. At the same time, the preparation method of the present application is simple and easy to implement, suitable for large-scale industrial production, and is conducive to promoting the further development of new energy vehicle charging cable technology.

[0005] In the first aspect, the present application provides a TPE sheath material for a charging cable using the following technical solution: A TPE sheath material for a charging cable comprises the following raw materials in percentage by mass: 15% to 20% polypropylene, 10% to 15% EPDM rubber, 40% to 50% hydrogenated styrene-ethylene-butadiene-styrene copolymer, 9% to 14% cyclohexane oil, 5% to 10% polyolefin elastomer, 1% to 3% black masterbatch, 0.5% to 2% tetraethylene pentamine, 1% to 3% chitosan and 2% to 5% lignin.

[0006] In the above technical scheme, the present application selects hydrogenated styrene-ethylene-butadiene-styrene copolymer (SEBS) as the main material, which can improve the weather resistance and chemical corrosion resistance of the TPE sheath material. By adding polypropylene and EPDM rubber, the mechanical properties and wear resistance of the sheath material are enhanced, especially the impact resistance of the TPE sheath material at low temperatures. The introduction of polyolefin elastomer can further enhance the elasticity and flexibility of the PE sheath material and ensure the stability during the molding process. The addition of cyclohexane oil effectively improves the processing performance of the TPE sheath material, which is easy to mold and has a good touch. The black masterbatch provides the required color for the TPE jacket material, while the addition of tetraethylenepentamine, chitosan and lignin produces a significant synergistic effect through a complex chemical and physical interaction mechanism, jointly constructing and strengthening the dynamic cross-linking network of the TPE jacket material, which not only improves the stability of the TPE jacket material, but also promotes the uniform dispersion of each raw material in the TPE jacket material, enhances the interface compatibility of each raw material, and reduces local stress concentration points. Therefore, when subjected to external forces, the TPE jacket material can disperse the forces more evenly, thereby greatly improving the overall mechanical strength and wear resistance of the TPE jacket material. At the same time, the antibacterial properties of chitosan, the environmental protection properties of lignin and the carbonized protective layer formed during combustion, combined with the dynamic cross-linking of tetraethylenepentamine, can effectively enhance the flame retardant properties of the TPE jacket material.

[0007] Preferably, the polypropylene is homopolypropylene.

[0008] In the above technical solution, by selecting homopolymer polypropylene as the source of polypropylene, the mechanical properties and wear resistance of the TPE (thermoplastic elastomer) sheath material are further optimized. Homopolymer polypropylene, with its high crystallinity and strength characteristics, can significantly improve the hardness and wear resistance of the TPE sheath material, so that the TPE sheath material can show better performance when facing various physical wear and mechanical stress, thereby extending the service life of the product and reducing maintenance costs to a certain extent.

[0009] Preferably, the polyolefin elastomer is an ethylene-octene copolymer grafted with maleic anhydride copolymer.

[0010] In the above technical solution, the ethylene-octene copolymer itself has good elasticity and flexibility. After further grafting with maleic anhydride, the number of its polar functional groups can be effectively increased, thereby significantly improving the interface compatibility between the ethylene-octene copolymer and other raw materials in the TPE sheath material. The TPE sheath material can be more easily mixed during the preparation process, thereby ensuring the homogeneity of the TPE sheath material and further enhancing the compatibility and processing performance of the TPE sheath material.

[0011] Preferably, 0.1% to 1% of an antioxidant is also included.

[0012] In the above technical solution, by adding an appropriate amount of antioxidant during the preparation of the TPE sheath material, the antioxidant properties of the TPE sheath material can be effectively improved, which helps to resist the performance degradation of the TPE sheath material caused by oxidation during use, thereby significantly extending the service life of the TPE sheath material.

[0013] Preferably, the antioxidant is antioxidant 1035.

[0014] In the above technical solution, the antioxidant is preferably antioxidant 1035, which has high thermal stability and antioxidant properties, and can effectively prevent the TPE sheath material from being degraded due to oxidation during processing and use, thereby maintaining its good physical properties and chemical stability.

[0015] Preferably, the viscosity index of the cyclohexane oil is ≥80.

[0016] In the above technical scheme, the present application limits the viscosity index of the cyclohexane oil to ≥80. The cyclohexane oil with a high viscosity index can play a good lubricating role in the TPE sheath material, reducing the friction and wear of the sheath material during the processing. At the same time, the cyclohexane oil with a high viscosity index can also improve the weather resistance of the TPE sheath material, so that it can still maintain stable performance in high or low temperature environments.

[0017] In the second aspect, the present application provides a method for preparing a TPE sheath material for a charging cable using the following technical solution: A method for preparing a TPE sheath material for a charging cable comprises the following steps: Step 1: Dry the hydrogenated styrene-ethylene-butadiene-styrene copolymer in a vacuum dryer at a temperature between 60 and 70° C. until the moisture content is less than 50 ppm.

[0018] Step 2: Add the raw materials into a twin-screw extruder, melt-blend and extrude at 160-170° C. to obtain a TPE sheath material for a charging cable.

[0019] In the above technical scheme, the preparation method of the present application is simple and easy to implement. By controlling the order of adding each raw material and the process parameters during the melt blending process, the raw materials can be fully mixed and evenly mixed, thereby improving the overall performance of the TPE sheath material for charging cables.

[0020] Preferably, the screw speed during the melt blending process in step 2 is 200 to 400 rpm.

[0021] In the above technical scheme, the present application sets the screw speed in the melt blending process in step 2 to 200-400 rpm, which can not only ensure that the materials are fully mixed, but also avoid molecular chain breakage or other adverse consequences caused by excessive shearing, thereby ensuring the high quality of the TPE sheath material for the charging cable.

[0022] In summary, the present application includes at least one of the following beneficial technical effects: 1. This application selects hydrogenated styrene-ethylene-butadiene-styrene copolymer, polypropylene and EPDM rubber as the main raw materials. This combination not only ensures that the TPE (thermoplastic elastomer) sheath material has excellent mechanical properties, but also significantly improves its weather resistance and chemical corrosion resistance, thereby improving the stability and service life of the charging cable under various environmental conditions, thereby ensuring that the charging cable can perform its functions normally and provide users with a reliable and long-lasting use experience.

[0023] 2. This application significantly improves the fluidity and formability of the TPE sheath material during the processing process by introducing ethylene-octene copolymer grafted maleic anhydride copolymer, which enables the TPE sheath material to be better combined with other materials in practical applications and is easier to process during the production process, thereby improving production efficiency.

[0024] 3. This application further improves the wear resistance and flame retardancy of the TPE sheath material by adding auxiliary raw materials such as tetraethylenepentamine, chitosan and lignin. The synergistic effect between tetraethylenepentamine, chitosan and lignin can well promote the uniform dispersion of each raw material in the TPE sheath material, reduce local stress concentration points, and significantly improve the wear resistance of the TPE sheath material. At the same time, the antibacterial properties of chitosan, the environmental protection properties of lignin and the carbonized protective layer formed during combustion, combined with the dynamic cross-linking of tetraethylenepentamine, can effectively enhance the flame retardant properties of the TPE sheath material.

[0025] 4. The preparation method of the present application is simple and easy to implement, suitable for large-scale industrial production, and is conducive to promoting the further development of new energy vehicle charging cable technology. DETAILED DESCRIPTION

[0026] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0027] Example 1 A TPE sheath material for a charging cable includes 17kg of polypropylene, 13kg of ethylene propylene diene monomer rubber, 41.4kg of hydrogenated styrene-ethylene-butadiene-styrene copolymer, 12kg of cyclohexane oil, 7kg of polyolefin elastomer, 2kg of black masterbatch, 1.5kg of tetraethylene pentamine, 2kg of chitosan, 4kg of lignin, and 0.1kg of antioxidant.

[0028] The polypropylene is homopolymer polypropylene purchased from Yanshan Petrochemical, brand: M1840.

[0029] Among them, EPDM rubber was purchased from Dow Chemical, USA, brand: IP 4640.

[0030] Among them, hydrogenated styrene-ethylene-butadiene-styrene copolymer was purchased from Dongguan Xinxin New Materials Co., Ltd., brand: TSRC SEBS6150.

[0031] Among them, cyclohexane oil was purchased from Xinji Luhua Petrochemical Co., Ltd. with a viscosity index of 109.

[0032] The polyolefin elastomer is ethylene-octene copolymer grafted maleic anhydride copolymer, purchased from Dow Chemical, USA, with the brand number: 8137.

[0033] Among them, the black masterbatch was purchased from Dongguan Jinsuyan Plastic Technology Co., Ltd., brand number: 167.

[0034] Among them, tetraethylenepentamine was purchased from Jinan Century Tongda Chemical Co., Ltd., brand: Japan Tosoh.

[0035] Chitosan was purchased from Qingdao Yuekang Biotechnology Co., Ltd.

[0036] Among them, lignin was purchased from Tesco Chemical (Hubei) Co., Ltd.

[0037] The antioxidant is BASF antioxidant Irganox 1035.

[0038] Among them, the preparation method of TPE sheath material for charging cable includes the following steps: Step 1: Dry the hydrogenated styrene-ethylene-butadiene-styrene copolymer in a vacuum dryer at a temperature of 65° C. until the moisture content is less than 50 ppm.

[0039] Step 2: Add the raw materials into a twin-screw extruder, melt blend and extrude at 165° C. and 300 rpm to obtain a TPE sheath material for a charging cable.

[0040] Example 2 A TPE sheath material for a charging cable, which is different from that in Example 1, includes 15 kg of polypropylene, 15 kg of ethylene propylene diene rubber, 42 kg of hydrogenated styrene-ethylene-butadiene-styrene copolymer, 14 kg of cyclohexane oil, 5 kg of polyolefin elastomer, 1 kg of black masterbatch, 2 kg of tetraethylene pentamine, 3 kg of chitosan, 2 kg of lignin, and 1 kg of antioxidant.

[0041] Among them, the preparation method of TPE sheath material for charging cable includes the following steps: Step 1: Dry the hydrogenated styrene-ethylene-butadiene-styrene copolymer in a vacuum dryer at a temperature of 70° C. until the moisture content is less than 50 ppm.

[0042] Step 2: Add the raw materials into a twin-screw extruder, melt-blend and extrude at 160° C. and 400 rpm to obtain a TPE sheath material for a charging cable.

[0043] Example 3 A TPE sheath material for a charging cable, which is different from Example 1 in that it includes 20kg of polypropylene, 10kg of ethylene propylene rubber, 41kg of hydrogenated styrene-ethylene-butadiene-styrene copolymer, 9kg of cyclohexane oil, 10kg of polyolefin elastomer, 3kg of black masterbatch, 0.5kg of tetraethylene pentamine, 1kg of chitosan, 5kg of lignin, and 0.5kg of antioxidant.

[0044] Among them, the preparation method of TPE sheath material for charging cable includes the following steps: Step 1: Dry the hydrogenated styrene-ethylene-butadiene-styrene copolymer in a vacuum dryer at a temperature of 60° C. until the moisture content is less than 50 ppm.

[0045] Step 2: Add the raw materials into a twin-screw extruder, melt blend and extrude at 170° C. and 200 rpm to obtain a TPE sheath material for a charging cable.

[0046] Comparative Example 1 A TPE sheath material for a charging cable, which is different from Example 1 in that tetraethylenepentamine, chitosan, and lignin are replaced by hydrogenated styrene-ethylene-butadiene-styrene copolymer in equal amounts.

[0047] Comparative Example 2 A TPE sheath material for a charging cable, which is different from Example 1 in that tetraethylenepentamine is replaced by triethylenetetramine in an equal amount.

[0048] Comparative Example 3 A TPE sheath material for a charging cable, which is different from Example 1 in that an equal amount of chitosan is replaced by lignin.

[0049] Comparative Example 4 A TPE sheath material for a charging cable, which is different from Example 1 in that an equal amount of lignin is replaced by chitosan.

[0050] Comparative Example 5 A TPE sheath material for a charging cable, which is different from Example 1 in that lignin is replaced by polystyrene in equal amounts, and is purchased from Zhenjiang Chimei, with a brand name of PH-88.

[0051] Performance Testing Tensile strength (MPa): Refer to ASTM D412 to test the tensile strength of TPE sheath material.

[0052] Tear strength (kN / m): Refer to ASTM D624 to test the tear strength of TPE sheath material.

[0053] Wear resistance: The prepared TPE sheath material sample was subjected to a wear test using an abrasion tester. The CS17 wheel was selected and the test was carried out at a load of 1000g / wheel and a rotation speed of 5000r / m. The mass change before and after abrasion was recorded and the wear loss (mg) was calculated.

[0054] Vertical combustion performance: refer to UL-94 standard, sample thickness 3.2mm The above test results are shown in Table 1.

[0055] Table 1: It can be seen from the data in Table 1 that the TPE sheath materials of Example 1, Example 2 and Example 3 all perform well in terms of tensile strength, tear strength, wear resistance and vertical burning performance. Specifically, the TPE sheath materials of Example 1, Example 2 and Example 3 all reach the V-0 grade of UL-94, indicating that the TPE sheath materials of the present application have good flame retardant properties. In addition, from the data of the wear amount, the wear amount of the TPE sheath materials of Example 1, Example 2 and Example 3 is relatively low, indicating that the wear resistance of the TPE sheath materials of the present application is good.

[0056] Specifically combined with Example 1 and Comparative Examples 1 to 5, the difference from Example 1 is that in Comparative Example 1, tetraethylene pentamine, chitosan, and lignin are replaced by hydrogenated styrene-ethylene-butadiene-styrene copolymer in equal amounts, in Comparative Example 2, tetraethylene pentamine is replaced by triethylenetetramine in equal amounts, in Comparative Examples 3 and 4, chitosan and lignin are interchanged, and in Comparative Example 5, lignin is replaced by polystyrene in equal amounts, while the comprehensive properties of Example 1 are good. It can be seen that the combination of tetraethylene pentamine, chitosan, and lignin has a particularity and plays an important role in improving the flame retardant properties and wear resistance of TPE sheath materials.

[0057] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A TPE sheath material for a charging cable, characterized in that: The invention comprises the following raw materials in percentage by weight: 15% to 20% of polypropylene, 10% to 15% of ethylene propylene diene rubber, 40% to 50% of hydrogenated styrene-ethylene-butadiene-styrene copolymer, 9% to 14% of cyclohexane oil, 5% to 10% of polyolefin elastomer, 1% to 3% of black masterbatch, 0.5% to 2% of tetraethylene pentamine, 1% to 3% of chitosan and 2% to 5% of lignin.

2. A TPE sheath material for a charging cable according to claim 1, characterized in that: The polypropylene is homopolymer polypropylene.

3. The TPE sheath material for a charging cable according to claim 1, characterized in that: The polyolefin elastomer is an ethylene-octene copolymer grafted with maleic anhydride copolymer.

4. The TPE sheath material for a charging cable according to claim 1, characterized in that: It also includes 0.1%~1% antioxidant.

5. The TPE sheath material for a charging cable according to claim 1, characterized in that: The antioxidant is antioxidant 1035.

6. The TPE sheath material for a charging cable according to claim 1, characterized in that: The viscosity index of the naphthenic oil is ≥80.

7. A method for preparing a TPE sheath material for a charging cable according to any one of claims 1 to 6, characterized in that: The steps include: Step 1: Drying the hydrogenated styrene-ethylene-butadiene-styrene copolymer in a vacuum dryer at a temperature between 60 and 70° C. until the moisture content is less than 50 ppm; Step 2: Add the raw materials into a twin-screw extruder, melt blend and extrude at 160-170°C to obtain a TPE sheath material for a charging cable.

8. The method for preparing a TPE sheath material for a charging cable according to claim 7, characterized in that: The screw speed during the melt blending process in step 2 is 200-400 rpm.

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