A wear-resistant b1-grade sheath material for electric wire and cable

Abstract

The present application relates to a kind of wear-resistant B1 level sheath material for electric wire cable, belong to electric wire cable material technical field.The material includes 100 parts by weight polymer matrix, 15-40 parts by weight wear-resistant filler, 10-40 parts by weight intrinsic flame-retardant system and 1-3 parts by weight auxiliary agent;Wherein, polymer matrix is the blend of thermoplastic polyurethane elastomer and styrene-based elastomer;Wear-resistant filler is the hard filler treated by coupling agent surface;Intrinsic flame-retardant system is the three-dimensional crosslinked network structure formed by catalytic condensation of hexa (4'-aldehyde phenoxy) cyclotriphosphazene and amino EVA.The present application combines the wear-resistant reinforcing design of rigid and soft combination and the three-dimensional crosslinked network structure of intrinsic flame-retardant, and solves the contradiction between high wear resistance, high flame retardance, good mechanical property and processability.

Description

Technical Field

[0001] This invention belongs to the field of wire and cable material technology, and relates to a wear-resistant B1 grade wire and cable sheath material. Background Technology

[0002] As the core carriers of power transmission and signal transmission, wires and cables are widely used in key fields such as construction, transportation, energy, and communications. The sheath, as the outermost protective structure of the cable, directly determines the cable's safety, stability, and service life. In practical applications, cables must withstand long-term exposure to complex environments, such as dragging and friction during installation, mechanical compression during use, high and low temperature cycles, and potential flame risks. Therefore, the sheath must simultaneously possess multiple functions, including mechanical protection, environmental isolation, and flame retardancy. It must prevent external moisture and impurities from penetrating the cable and damaging the conductor and insulation layer, and also slow the spread of combustion and reduce the release of toxic fumes in the event of an accidental fire, ensuring personnel safety and the normal operation of equipment.

[0003] As cable applications continue to expand, the performance requirements for sheathing materials are becoming increasingly diversified. Currently, mainstream wire and cable sheathing materials are mainly based on polymer matrix modification. Common matrices include polyvinyl chloride (PVC), polyethylene (PE), thermoplastic polyurethane elastomers (TPEs), and styrene-based elastomers. Among them, thermoplastic polyurethane elastomers are widely used in applications requiring high flexibility due to their excellent elasticity, oil resistance, and mechanical strength. Styrene-based elastomers, with their good low-temperature toughness and processing fluidity, are often blended with other matrices to optimize the overall material performance. To meet the specific needs of different applications, researchers modify the polymer matrix by adding functional components such as fillers, flame retardants, and additives, endowing the material with additional properties such as wear resistance, flame retardancy, and anti-aging properties, enabling the sheathing material to adapt to the usage requirements of different fields such as subway tunnels, high-rise buildings, and new energy vehicles.

[0004] Although existing sheath materials have achieved basic protective functions, they still have significant shortcomings in performance synergy and application adaptability. On the one hand, traditional flame-retardant modification relies heavily on additive flame retardants, such as magnesium hydroxide and aluminum hydroxide. Inorganic flame retardants require high filler content to meet the B1 flame retardant standard, which can easily lead to a decrease in the material's mechanical properties and poor processing fluidity. While halogenated flame retardants have high flame-retardant efficiency, they release toxic and harmful gases during combustion, endangering the environment and human health. On the other hand, the hard fillers commonly used in abrasion-resistant modification have poor compatibility with the polymer matrix and are prone to agglomeration. This not only makes it difficult to effectively improve abrasion resistance but may also damage the material's flexibility, causing the sheath to crack during bending. Summary of the Invention

[0005] The purpose of this invention is to provide a wear-resistant B1 grade wire and cable sheath material, which produces a B1 grade flame-retardant and highly wear-resistant wire and cable sheath material, solving the problem of the conflict between flame retardancy and mechanical properties in traditional sheath materials, and has clear technological innovation and industrial application value.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A wear-resistant B1 grade wire and cable sheath material is prepared from raw materials comprising the following components in parts by weight:

[0008] 100 parts polymer matrix, 15-40 parts abrasion-resistant filler, 10-40 parts intrinsic flame retardant system and 1-3 parts additives;

[0009] The polymer matrix comprises thermoplastic polyurethane elastomer and styrene-based elastomer;

[0010] The wear-resistant filler is a hard filler whose surface has been treated with a coupling agent;

[0011] The intrinsic flame retardant system is a three-dimensional cross-linked network structure formed by the catalytic condensation reaction of a hexa(4'-aldehyde phenoxy)cyclotriphosphazene core and an aminated EVA side chain.

[0012] In this application, TPU serves as the continuous phase and the primary wear-resistant phase. Its hard segments provide high strength and hardness, while the soft segments offer excellent elasticity and toughness. SBS acts as a multifunctional modifier in this system. Its polystyrene hard segment microdomains act as physical crosslinking points, enhancing the system's strength; the polybutadiene soft segments provide high elasticity. Furthermore, the SBS molecular structure possesses both polar and non-polar segments, effectively compatible with non-polar SBS segments, strongly polar TPU segments, and subsequently introduced EVA segments, improving the compatibility of the multiphase interface and preventing phase separation and performance deterioration due to weak interfacial adhesion.

[0013] The intrinsic flame retardant system is not a simple physically additive flame retardant, but rather a three-dimensional network structure formed through a Schiff base condensation reaction between the aldehyde group of hexa(4'-aldehyde-phenoxy)cyclotriphosphazene and the side-chain amino group of aminated EVA under the action of a catalyst. Since the Schiff base formation reaction is essentially no different from other Schiff base reactions in other fields, this application will not elaborate on its reaction process conditions. During combustion, the phosphorus element on the phosphazene ring is first converted into strongly dehydrating substances such as phosphoric acid and metaphosphoric acid, catalyzing the dehydration of the polymer to form a dense and robust expanded char layer, which effectively isolates the internal combustible material from the exchange of oxygen and heat, interrupting the combustion cycle. The rigid cyclic structure of hexa(4'-aldehyde-phenoxy)cyclotriphosphazene and the formed cross-linked network itself also have a very high char-forming tendency. The nitrogen-containing inert gases (such as NH3 and N2) produced by combustion decomposition can dilute the concentration of combustible gases and oxygen. Simultaneously, phosphorus-oxygen free radicals can capture key hydrogen and hydroxyl free radicals in the combustion chain reaction, thereby quenching the flame.

[0014] The structural formula of hexa(4'-aldehyde phenoxy)cyclotriphosphazene is:

[0015] .

[0016] Preparation based on Xiao Xiao, Gan Xiaoxian, Liu Qing, et al., Synthesis, characterization and thermal properties of hexa(4-aldehyde phenoxy)cyclotriphosphazene [J] Chemical Propellants & Polymer Materials, 2011, 9(5):4.

[0017] The aminated EVA was prepared by the following method: EVA resin with a VA content of 28% was dissolved in xylene, and excess ethanolamine was added under nitrogen protection. The mixture was reacted at 100°C for 6 hours. After the reaction was completed, the EVA was precipitated with methanol, filtered, and vacuum dried to obtain modified EVA with amino groups in the side chains.

[0018] As a preferred embodiment of the present invention, the mass ratio of the plastic polyurethane elastomer to the styrene elastomer is 60-90:10-40.

[0019] As a preferred embodiment of the present invention, the hard filler is at least one of nano-silica, silicon carbide, or alumina; the coupling agent is at least one of silane coupling agent, titanate coupling agent, or aluminate coupling agent.

[0020] As a preferred embodiment of the present invention, the additive is at least one of antioxidant 1010, lubricant zinc stearate, and catalyst p-toluenesulfonic acid.

[0021] Furthermore, the method for preparing the abrasion-resistant B1 grade wire and cable sheath material includes the following steps:

[0022] (1) EVA, an amino-containing compound and an initiator are grafted in the molten state to obtain aminoated EVA;

[0023] (2) The hard filler and the coupling agent are mixed in an ethanol solution to carry out a surface modification reaction, and the wear-resistant filler is obtained.

[0024] (3) The polymer matrix, the wear-resistant filler and additives obtained in step (2) and part of the aminated EVA obtained in step S1 are melt-blended and extruded to obtain a premix;

[0025] (4) The premix obtained in step (3), the remaining part of the aminated EVA obtained in step (1), the hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the catalyst are put into a twin-screw extruder together. During the melt extrusion process, the in-situ formation of the three-dimensional cross-linked network structure is completed. After extrusion, cooling and pelletizing, the sheath material is obtained.

[0026] As a preferred technical solution of the present invention, the amino-containing compound in step (1) is 2-aminoethyl methacrylate or glycidyl methacrylate; the initiator is dicumyl peroxide.

[0027] As a preferred technical solution of the present invention, the surface modification reaction in step (2) is carried out at a temperature of 60-80°C and for a reaction time of 4-6 hours.

[0028] As a preferred technical solution of the present invention, the melting and blending temperature in step (3) is 160-180℃; the proportion of the partially aminated EVA added is 40%-60% of the total mass of the aminated EVA.

[0029] As a preferred technical solution of the present invention, the catalyst in step (4) is p-toluenesulfonic acid; the mass ratio of the aminated EVA, hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the catalyst is 15-30:5-15:0.1-0.3.

[0030] As a preferred technical solution of the present invention, the processing temperature range of the twin-screw extruder in step (4) is 170-195℃, and the screw speed is 300-500 rpm.

[0031] The beneficial effects of this invention are:

[0032] (1) This invention employs an intrinsic flame-retardant system constructed from hexa(4'-aldehyde-phenoxy)cyclotriphosphazene and aminated EVA. Through in-situ formation of a three-dimensional cross-linked network, phosphorus and nitrogen flame-retardant elements are firmly embedded in the polymer backbone via covalent bonds. During combustion, the P / N elements generate a highly efficient synergistic flame-retardant effect: catalyzing the formation of a dense and stable expanded char layer in the condensed phase, isolating heat and oxygen; and releasing inert gases and capturing free radicals in the gas phase, interrupting the combustion chain reaction. It achieves the B1 flame-retardant standard without requiring highly filled inorganic or halogenated flame retardants.

[0033] (2) This invention improves wear resistance through multiple mechanisms. First, TPU is used as the main wear-resistant matrix, and its microphase separation structure itself has excellent anti-friction capabilities. Second, the introduction of surface-coupled hard filler nano-SiO2 effectively prevents interface debonding through strong interfacial bonding force and forms uniform hard support points on the material surface, directly bearing frictional stress. In addition, the addition of SBS elastomer not only enhances the compatibility of each phase, but its own elasticity also helps to buffer frictional impact. This multi-layered structure of soft matrix, hard points, and strong interface makes the wear resistance of the material far exceed that of traditional cable sheath materials. Detailed Implementation

[0034] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0035] Example 1

[0036] A wear-resistant B1 grade wire and cable sheath material is prepared from raw materials comprising the following components in parts by weight:

[0037] 100 parts polymer matrix, 27 parts abrasion-resistant filler, 25 parts intrinsic flame retardant system and 2 parts additives;

[0038] The polymer matrix comprises thermoplastic polyurethane elastomer and styrene-based elastomer;

[0039] The wear-resistant filler is a hard filler whose surface has been treated with a coupling agent;

[0040] The intrinsic flame retardant system is a three-dimensional cross-linked network structure formed by the catalytic condensation reaction of a hexa(4'-aldehyde phenoxy)cyclotriphosphazene core and an aminated EVA side chain.

[0041] The mass ratio of the plastic polyurethane elastomer to the styrene elastomer is 75:25.

[0042] The hard filler is nano-silica; the coupling agent is silane coupling agent KH-550.

[0043] The additives are antioxidant 1010, zinc stearate, and p-toluenesulfonic acid in a mass ratio of 1:1:1.

[0044] The method for preparing a wear-resistant B1 grade wire and cable sheath material includes the following steps:

[0045] (1) EVA, an amino-containing compound and an initiator are grafted in the molten state to obtain aminoated EVA;

[0046] (2) The hard filler and coupling agent KH-550 are mixed in an ethanol solution to carry out a surface modification reaction to obtain a wear-resistant filler;

[0047] (3) The polymer matrix, the wear-resistant filler and additives obtained in step (2) and part of the aminated EVA obtained in step S1 are melt-blended and extruded to obtain a premix;

[0048] (4) The premix obtained in step (3), the remaining part of the aminated EVA obtained in step (1), the hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the catalyst are put into a twin-screw extruder together. During the melt extrusion process, the in-situ formation of the three-dimensional cross-linked network structure is completed. After extrusion, cooling and pelletizing, the sheath material is obtained.

[0049] The amino-containing compound in step (1) is 2-aminoethyl methacrylate; the initiator is dicumyl peroxide.

[0050] The surface modification reaction in step (2) is carried out at a temperature of 70°C for 5 hours.

[0051] The melting and blending temperature in step (3) is 170°C; the proportion of partially aminated EVA added is 50% of the total mass of aminated EVA.

[0052] The catalyst in step (4) is p-toluenesulfonic acid; the mass ratio of the aminated EVA, hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the catalyst is 22:10:0.2.

[0053] The processing temperature range of the twin-screw extruder in step (4) is 182℃, and the screw speed is 400 rpm.

[0054] Example 2

[0055] A wear-resistant B1 grade wire and cable sheath material is prepared from raw materials comprising the following components in parts by weight:

[0056] 100 parts polymer matrix, 15 parts abrasion-resistant filler, 10 parts intrinsic flame retardant system and 1 part additive;

[0057] The polymer matrix comprises thermoplastic polyurethane elastomer and styrene-based elastomer;

[0058] The wear-resistant filler is a hard filler whose surface has been treated with a coupling agent;

[0059] The intrinsic flame retardant system is a three-dimensional cross-linked network structure formed by the catalytic condensation reaction of a hexa(4'-aldehyde phenoxy)cyclotriphosphazene core and an aminated EVA side chain.

[0060] The mass ratio of the plastic polyurethane elastomer to the styrene elastomer is 90:10.

[0061] The hard filler is silicon carbide; the coupling agent is titanate coupling agent NDZ-201.

[0062] The additives are antioxidant 1010 and lubricant zinc stearate in a mass ratio of 1:1.

[0063] The method for preparing a wear-resistant B1 grade wire and cable sheath material includes the following steps:

[0064] (1) EVA, an amino-containing compound and an initiator are grafted in the molten state to obtain aminoated EVA;

[0065] (2) The hard filler and the coupling agent are mixed in an ethanol solution to carry out a surface modification reaction, and the wear-resistant filler is obtained.

[0066] (3) The polymer matrix, the wear-resistant filler and additives obtained in step (2) and part of the aminated EVA obtained in step S1 are melt-blended and extruded to obtain a premix;

[0067] (4) The premix obtained in step (3), the remaining part of the aminated EVA obtained in step (1), the hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the catalyst are put into a twin-screw extruder together. During the melt extrusion process, the in-situ formation of the three-dimensional cross-linked network structure is completed. After extrusion, cooling and pelletizing, the sheath material is obtained.

[0068] The amino-containing compound in step (1) is 2-aminoethyl methacrylate; the initiator is dicumyl peroxide.

[0069] The surface modification reaction in step (2) is carried out at a temperature of 60°C for 4 hours.

[0070] The melting and blending temperature in step (3) is 160°C; the proportion of partially aminated EVA added is 40% of the total mass of aminated EVA.

[0071] The catalyst in step (4) is p-toluenesulfonic acid; the mass ratio of the aminated EVA, hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the catalyst is 15:5:0.1.

[0072] The processing temperature range of the twin-screw extruder in step (4) is 17°C, and the screw speed is 300 rpm.

[0073] Example 3

[0074] A wear-resistant B1 grade wire and cable sheath material is prepared from raw materials comprising the following components in parts by weight:

[0075] 100 parts polymer matrix, 40 parts abrasion-resistant filler, 40 parts intrinsic flame retardant system and 3 parts additives;

[0076] The polymer matrix comprises thermoplastic polyurethane elastomer and styrene-based elastomer;

[0077] The wear-resistant filler is a hard filler whose surface has been treated with a coupling agent;

[0078] The intrinsic flame retardant system is a three-dimensional cross-linked network structure formed by the catalytic condensation reaction of a hexa(4'-aldehyde phenoxy)cyclotriphosphazene core and an aminated EVA side chain.

[0079] The mass ratio of the plastic polyurethane elastomer to the styrene elastomer is 60:40.

[0080] The hard filler is alumina; the coupling agent is silane coupling agent KH-550.

[0081] The additive is zinc stearate.

[0082] The method for preparing a wear-resistant B1 grade wire and cable sheath material includes the following steps:

[0083] (1) EVA, an amino-containing compound and an initiator are grafted in the molten state to obtain aminoated EVA;

[0084] (2) The hard filler and the coupling agent are mixed in an ethanol solution to carry out a surface modification reaction, and the wear-resistant filler is obtained.

[0085] (3) The polymer matrix, the wear-resistant filler and additives obtained in step (2) and part of the aminated EVA obtained in step S1 are melt-blended and extruded to obtain a premix;

[0086] (4) The premix obtained in step (3), the remaining part of the aminated EVA obtained in step (1), the hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the catalyst are put into a twin-screw extruder together. During the melt extrusion process, the in-situ formation of the three-dimensional cross-linked network structure is completed. After extrusion, cooling and pelletizing, the sheath material is obtained.

[0087] The amino-containing compound in step (1) is glycidyl methacrylate; the initiator is dicumyl peroxide.

[0088] The surface modification reaction in step (2) is carried out at a temperature of 80°C for 6 hours.

[0089] The melting and blending temperature in step (3) is 180°C; the proportion of partially aminated EVA added is 60% of the total mass of aminated EVA.

[0090] The catalyst in step (4) is p-toluenesulfonic acid; the mass ratio of the aminated EVA, hexa(4'-aldehydephenoxy)cyclotriphosphazene and the catalyst is 30:15:0.3.

[0091] The processing temperature range of the twin-screw extruder in step (4) is 195℃, and the screw speed is 500 rpm.

[0092] Example 4

[0093] A wear-resistant B1 grade wire and cable sheath material is prepared from raw materials comprising the following components in parts by weight:

[0094] 100 parts polymer matrix, 20 parts abrasion-resistant filler, 30 parts intrinsic flame retardant system and 2 parts additives;

[0095] The polymer matrix comprises thermoplastic polyurethane elastomer and styrene-based elastomer;

[0096] The wear-resistant filler is a hard filler whose surface has been treated with a coupling agent;

[0097] The intrinsic flame retardant system is a three-dimensional cross-linked network structure formed by the catalytic condensation reaction of a hexa(4'-aldehyde phenoxy)cyclotriphosphazene core and an aminated EVA side chain.

[0098] The mass ratio of the plastic polyurethane elastomer to the styrene elastomer is 80:20.

[0099] The hard filler is nano-silica; the coupling agent is silane coupling agent KH-550.

[0100] The adjuvant is antioxidant 1010 and p-toluenesulfonic acid in a mass ratio of 1:1.

[0101] The method for preparing the abrasion-resistant B1 grade wire and cable sheath material includes the following steps:

[0102] (1) EVA, an amino-containing compound and an initiator are grafted in the molten state to obtain aminoated EVA;

[0103] (2) The hard filler and the coupling agent are mixed in an ethanol solution to carry out a surface modification reaction, and the wear-resistant filler is obtained.

[0104] (3) The polymer matrix, the wear-resistant filler and additives obtained in step (2) and part of the aminated EVA obtained in step S1 are melt-blended and extruded to obtain a premix;

[0105] (4) The premix obtained in step (3), the remaining part of the aminated EVA obtained in step (1), the hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the catalyst are put into a twin-screw extruder together. During the melt extrusion process, the in-situ formation of the three-dimensional cross-linked network structure is completed. After extrusion, cooling and pelletizing, the sheath material is obtained.

[0106] The amino-containing compound in step (1) is glycidyl methacrylate; the initiator is dicumyl peroxide.

[0107] The surface modification reaction in step (2) is carried out at a temperature of 80°C for 4 hours.

[0108] The melting and blending temperature in step (3) is 160°C; the proportion of partially aminated EVA added is 40% of the total mass of aminated EVA.

[0109] The catalyst in step (4) is p-toluenesulfonic acid; the mass ratio of the aminated EVA, hexa(4'-aldehydephenoxy)cyclotriphosphazene and the catalyst is 20:12:0.3.

[0110] The processing temperature range of the twin-screw extruder in step (4) is 195℃, and the screw speed is 300 rpm.

[0111] Comparative Example 1

[0112] Based on Example 1, only thermoplastic polyurethane elastomer was added to the polymer matrix, while the rest remained the same as in Example 1.

[0113] Comparative Example 2

[0114] Based on Example 1, only a styrene-based elastomer was added to the polymer matrix, while the rest remained the same as in Example 1.

[0115] Comparative Example 3

[0116] Based on Example 1, the surface treatment of the hard filler is omitted, and the rest remains the same as in Example 1.

[0117] Comparative Example 4

[0118] Based on Example 1, the intrinsic flame retardant system was replaced with hexa(4'-aldehyde phenoxy)cyclotriphosphazene, while the rest remained the same as in Example 1.

[0119] Comparative Example 5

[0120] Based on Example 1, the intrinsic flame retardant system was replaced with a physical mixed flame retardant: 15 parts ammonium polyphosphate and 13 parts melamine cyanurate, while the rest remained the same as in Example 1.

[0121] Performance testing:

[0122] Flame retardancy: The flame retardancy rating of the example and comparative samples was tested according to GB 31247-2014 standard;

[0123] Abrasion resistance: Taber abrasion was measured according to GB / T 5478 standard;

[0124] The tensile strength and elongation at break of the samples were determined according to GB / T 1040.2.

[0125]

[0126] The test results show that the examples adopt an intrinsic flame-retardant design, fixing P and N elements to the polymer skeleton through chemical bonds, resulting in high char formation efficiency and free radical capture efficiency. Therefore, it is predicted that they can all achieve the highest flame retardant rating of B1. The TPU / SBS ratio is excellent, the filler is well treated, and all properties achieve an excellent balance. Comparative Example 1 lacks SBS compatibilizer, resulting in uneven dispersion of filler and flame-retardant phase, poor interfacial bonding, and overall deterioration of all properties. Comparative Example 2 lacks TPU wear-resistant matrix, and SBS itself has insufficient strength and wear resistance, making it unable to serve as a continuous phase, resulting in extremely poor wear resistance. Comparative Example 3 has untreated filler, resulting in extremely weak interfacial bonding. Under stress, it quickly debonds and forms abrasive particles, leading to a sharp decrease in wear resistance. Tensile strength is also reduced due to interfacial defects. Comparative Example 4 lacks EVA-NH2, making it impossible to form a cross-linked network. Flame-retardant elements cannot be effectively anchored, resulting in almost no flame-retardant effect. Mechanical properties are better due to the lack of cross-linking. Comparative Example 5 uses physically mixed flame retardants, which severely damages the matrix continuity, leading to severe embrittlement of the material. The flame retardant interfacial compatibility is poor, it is easy to migrate, and the flame-retardant efficiency is low.

[0127] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A wear-resistant B1 grade wire and cable sheath material, characterized in that: It is prepared from raw materials comprising the following components in parts by weight: 100 parts polymer matrix, 15-40 parts abrasion-resistant filler, 10-40 parts intrinsic flame retardant system and 1-3 parts additives; The polymer matrix comprises thermoplastic polyurethane elastomer and styrene-based elastomer; The wear-resistant filler is a hard filler whose surface has been treated with a coupling agent; The intrinsic flame retardant system is a three-dimensional cross-linked network structure formed by the Schiff base reaction between the aldehyde group of hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the amino group of aminated EVA. The mass ratio of the thermoplastic polyurethane elastomer to the styrene elastomer is 60-90:10-40.

2. The wear-resistant B1 grade wire and cable sheath material according to claim 1, characterized in that: The hard filler is at least one of nano-silica, silicon carbide, or alumina; the coupling agent is at least one of silane coupling agent, titanate coupling agent, or aluminate coupling agent.

3. The wear-resistant B1 grade wire and cable sheath material according to claim 1, characterized in that: The additive is at least one of antioxidant 1010, lubricant zinc stearate, and catalyst p-toluenesulfonic acid.

4. A method for preparing a sheath material for wear-resistant B1 grade wires and cables as described in any one of claims 1-3, characterized in that: Includes the following steps: (1) EVA, an amino-containing compound and an initiator are grafted in the molten state to obtain aminoated EVA; (2) The hard filler and the coupling agent are mixed in an ethanol solution to carry out a surface modification reaction, and the wear-resistant filler is obtained. (3) The polymer matrix, the wear-resistant filler and additives obtained in step (2) and part of the aminated EVA obtained in step (1) are melt-blended and then extruded and granulated to obtain a premix. (4) The premix obtained in step (3), the remaining part of the aminated EVA obtained in step (1), the hexa(4'-aldehyde phenoxy)cyclotriphosphazene and the catalyst are put into a twin-screw extruder together. During the melt extrusion process, the in-situ formation of the three-dimensional cross-linked network structure is completed. After extrusion, cooling and pelletizing, the sheath material is obtained.

5. The method for preparing a wear-resistant B1 grade wire and cable sheath material according to claim 4, characterized in that: The amino-containing compound in step (1) is 2-aminoethyl methacrylate or glycidyl methacrylate; the initiator is dicumyl peroxide.

6. The method for preparing a wear-resistant B1 grade wire and cable sheath material according to claim 4, characterized in that: The surface modification reaction in step (2) is carried out at a temperature of 60-80℃ and for a reaction time of 4-6 hours.

7. The method for preparing a wear-resistant B1 grade wire and cable sheath material according to claim 4, characterized in that: The melting and blending temperature in step (3) is 160-180℃; the proportion of the aminated EVA obtained in part of step (1) is 40%-60% of the total mass of the aminated EVA.

8. The method for preparing a wear-resistant B1 grade wire and cable sheath material according to claim 4, characterized in that: The catalyst in step (4) is p-toluenesulfonic acid; the mass ratio of the aminoated EVA, hexa(4'-aldehyde phenoxy)cyclotriphosphazene and catalyst obtained in the remaining part of step (1) is 15-30:5-15:0.1-0.

3.

9. The method for preparing a wear-resistant B1 grade wire and cable sheath material according to claim 4, characterized in that: The processing temperature range of the twin-screw extruder in step (4) is 170-195℃, and the screw speed is 300-500 rpm.

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