Flame resistant cloth wire

Abstract

The application relates to the technical field of cloth electric wires, and discloses a flame-retardant cloth electric wire which comprises a conductor, an insulating layer and a sheath layer arranged from inside to outside in sequence, the sheath layer comprises the following components by weight: linear low-density polyethylene 60-70 parts, ethylene-vinyl acetate copolymer 15-20 parts, a flame retardant 50-60 parts, a compatibilizer 4-6 parts and an auxiliary agent 2-5 parts, the flame retardant comprises the following components by weight: aluminum hydroxide 60-70 parts, aluminum hypophosphite 10-15 parts, zinc borate 6-8 parts, composite modifier A 4-5 parts and composite modifier B 0.8-1 part, and the compositions of the composite modifier A and the composite modifier B are different. Through the technical scheme, the problem of insufficient flame-retardant performance of the cloth electric wire in the related art is solved.

Description

Technical Field

[0001] This invention relates to the field of electrical wiring technology, and more specifically, to a flame-retardant electrical wiring. Background Technology

[0002] Electrical wiring is the basic material for building power distribution and internal power supply of equipment. This type of wiring is used in residential buildings, shopping malls, schools, office buildings and other civil buildings. It is also widely used in electrical equipment such as air conditioners, water heaters, industrial control instruments, distribution cabinets, and small power tools. It is an indispensable basic supporting material for various power environments.

[0003] However, existing technologies for electrical wiring still have shortcomings in terms of flame retardant performance. Current flame retardants mostly use inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide. Inorganic powders have strong surface polarity and require large quantities, resulting in poor compatibility with the matrix and a tendency for agglomeration, weakening flame retardant performance. Insufficiently flame-retardant wiring will rapidly melt, crack, and detach when exposed to open flames, failing to provide oxygen and heat insulation protection for the internal insulation core. Flames can directly penetrate the damaged sheath and continue to burn the inner insulation layer; the flames can spread rapidly along the cable bundle, and the burning process will also produce a large amount of molten drippings that ignite surrounding decorative panels, soft furnishings, and other flammable materials, causing personal injury or economic loss.

[0004] Therefore, it is very necessary to develop a flame-retardant electrical wire. Summary of the Invention

[0005] This invention proposes a flame-retardant electrical wire to solve or alleviate the above-mentioned problems.

[0006] The technical solution of the present invention is as follows: This invention proposes a flame-retardant electrical wire, comprising a conductor, an insulation layer, and a sheath layer arranged sequentially from the inside out. The sheath layer comprises the following raw materials in parts by weight: 60-70 parts of linear low-density polyethylene, 15-20 parts of ethylene-vinyl acetate copolymer, 50-60 parts of flame retardant, 4-6 parts of compatibilizer, and 2-5 parts of additives. The flame retardant comprises the following raw materials in parts by weight: 60-70 parts of aluminum hydroxide, 10-15 parts of aluminum phosphonate, 6-8 parts of zinc borate, 4-5 parts of composite modifier A, and 0.8-1 parts of composite modifier B. The compositions of composite modifier A and composite modifier B are different.

[0007] Preferably, the conductor is made of copper.

[0008] Preferably, the insulating layer is a cross-linked polyethylene insulating layer.

[0009] Preferably, the composite modifier A is composed of a glycidyl ether type epoxy silane coupling agent and stearic acid in a mass ratio of 1~1.5:0.8.

[0010] Preferably, the glycidyl ether type epoxy silane coupling agent includes one or two of 3-glycidylpropyltrimethoxysilane and 3-glycidyl etheroxypropyltriethoxysilane.

[0011] Preferably, the composite modifier B is composed of an alicyclic epoxy silane coupling agent and a vinyl silane coupling agent in a mass ratio of 5 to 8:4.

[0012] Preferably, the alicyclic epoxy silane coupling agent is 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, and the vinyl silane coupling agent is composed of vinylphenyl silane coupling agent and vinylbenzylamino silane coupling agent in a mass ratio of 2~2.5:1.

[0013] Preferably, the vinylphenyl silane coupling agent includes one or both of vinylphenyl methyl methoxysilane and diphenyl vinylethoxysilane, and the vinylbenzylaminosilane coupling agent is vinylbenzylaminoethylaminopropyltrimethoxysilane.

[0014] Preferably, the preparation method of the flame retardant includes the following steps: dispersing composite modifier A in a solvent, adding aluminum hydroxide, mixing and drying to obtain modified aluminum hydroxide; dispersing composite modifier B in a solvent, adding aluminum hypophosphite, mixing and drying to obtain modified aluminum hypophosphite; and mixing the modified aluminum hydroxide, the modified aluminum hypophosphite and the zinc borate to obtain the flame retardant.

[0015] Preferably, the aluminum hypophosphite is composed of organic aluminum hypophosphite and inorganic aluminum hypophosphite in a mass ratio of 8 to 10:1, wherein the organic aluminum hypophosphite is diethyl aluminum hypophosphite.

[0016] Preferably, the compatibilizer is maleic anhydride-grafted polyethylene.

[0017] Preferably, the additive is composed of an antioxidant, a lubricant, and an ultraviolet absorber in a mass ratio of 2~3:1.5~2:0.5.

[0018] The working principle and beneficial effects of this invention are as follows: In this invention, aluminum hydroxide, aluminum hypophosphite, and zinc borate are added as the main flame retardant components to the sheath layer of the electrical wire. The composite flame retardant system reduces the amount of aluminum hydroxide used. Aluminum hypophosphite is an organophosphorus flame retardant component that can promote the rapid formation of a continuous and dense char layer at high temperatures. Zinc borate plays a synergistic role in suppressing smoke and preventing dripping. The combination of the three produces a synergistic effect, improving the flame retardant performance of the electrical wire. The addition of two sets of modifiers can reduce the surface polarity of the inorganic powder, improve the interfacial bonding force between the inorganic flame retardant components and the polyethylene matrix, avoid the agglomeration of the powder, and ensure that the flame retardant components are uniformly dispersed inside the sheath substrate without local flame retardant component gaps or accumulation defects. The overall flame retardant performance of the sheath is uniform and stable, thus improving the flame retardant performance of the electrical wire. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will be described through embodiments.

[0021] A specific embodiment of the first aspect of the present invention provides a flame-retardant electrical wire, comprising a conductor, an insulation layer, and a sheath layer arranged sequentially from the inside out. The sheath layer comprises the following raw materials in parts by weight: 60-70 parts of linear low-density polyethylene, 15-20 parts of ethylene-vinyl acetate copolymer, 50-60 parts of flame retardant, 4-6 parts of compatibilizer, and 2-5 parts of additives. The flame retardant comprises the following raw materials in parts by weight: 60-70 parts of aluminum hydroxide, 10-15 parts of aluminum phosphonate, 6-8 parts of zinc borate, 4-5 parts of composite modifier A, and 0.8-1 parts of composite modifier B. The compositions of composite modifier A and composite modifier B are different.

[0022] In this invention, linear low-density polyethylene is used as the main substrate of the sheath, exhibiting excellent mechanical strength and wear resistance. Ethylene-vinyl acetate copolymer improves the flexibility of the matrix and enhances the capacity to hold inorganic powders. Compatibilizers are used to improve the interfacial bonding between the resin matrix and the inorganic flame-retardant powders. Additives are used to optimize extrusion processing performance and material aging resistance. The composite modifiers A and B in the flame retardant have different compositions, allowing for surface modification of various inorganic flame-retardant powders from different dimensions, reducing powder surface polarity and improving the problems of powder agglomeration and uneven dispersion. Aluminum hydroxide is used as the main inorganic endothermic flame-retardant filler, aluminum phosphinate efficiently catalyzes char formation, and zinc borate plays a synergistic role in smoke suppression and anti-dripping. These three types of flame-retardant components work together to synergistically improve the flame-retardant performance of the electrical wire.

[0023] In one embodiment of the present invention, the conductor is made of copper.

[0024] In one embodiment of the present invention, the insulating layer is a cross-linked polyethylene insulating layer.

[0025] In one embodiment of the present invention, the composite modifier A is composed of a glycidyl ether type epoxy silane coupling agent and stearic acid in a mass ratio of 1~1.5:0.8.

[0026] In one embodiment of the present invention, the glycidyl ether type epoxy silane coupling agent includes one or two of 3-glycidylpropyltrimethoxysilane and 3-glycidyl etheroxypropyltriethoxysilane.

[0027] In one embodiment of the present invention, the composite modifier B is composed of an alicyclic epoxy silane coupling agent and a vinyl silane coupling agent in a mass ratio of 5 to 8:4.

[0028] In one embodiment of the present invention, the alicyclic epoxy silane coupling agent is 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, and the vinyl silane coupling agent is composed of vinylphenyl silane coupling agent and vinylbenzylamino silane coupling agent in a mass ratio of 2~2.5:1.

[0029] In one embodiment of the present invention, the vinylphenylsilane coupling agent includes one or two of vinylphenylmethylmethoxysilane and diphenylvinylethoxysilane, preferably vinylphenylmethylmethoxysilane, and the vinylbenzylaminosilane coupling agent is vinylbenzylaminoethylaminopropyltrimethoxysilane.

[0030] In one embodiment of the present invention, the method for preparing the flame retardant includes the following steps: dispersing composite modifier A in a solvent, adding aluminum hydroxide, mixing for 2 hours and then drying to obtain modified aluminum hydroxide; dispersing composite modifier B in a solvent, adding aluminum hypophosphite, mixing for 2 hours and then drying to obtain modified aluminum hypophosphite; mixing modified aluminum hydroxide, modified aluminum hypophosphite and zinc borate to obtain the flame retardant; the solvent is anhydrous ethanol, and the mass ratio of solvent to powder is 3~8:1, for example, it can be 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, preferably 5:1.

[0031] In this invention, composite modifier A is composed of a glycidyl ether type epoxy silane coupling agent and stearic acid. One end of the glycidyl ether type epoxy silane coupling agent carries a siloxane group, which can bond with a large number of hydroxyl groups on the surface of aluminum hydroxide powder. The epoxy active group at the other end of the molecule can generate bonding force with the linear low-density polyethylene and ethylene-vinyl acetate copolymer in the sheath matrix. Stearic acid weakens the strongly polar surface of aluminum hydroxide, reducing the electrostatic adsorption force between powders and preventing the aluminum hydroxide powder from agglomerating. Composite modifier B is composed of... It is a compound of cycloalcoholic epoxy silane coupling agent and vinyl silane coupling agent; compared with glycidyl ether type epoxy silane coupling agent, cycloalcoholic epoxy silane coupling agent has higher chemical stability due to its rigid epoxy structure and is more suitable for the surface of aluminum hypophosphite powder. Vinyl silane coupling agent can generate good compatibility and bonding force with the substrate of the sheath, reduce the micropores inside the sheath, improve the material density, effectively block the inward conduction of oxygen and heat during combustion, strengthen the heat insulation and oxygen barrier flame retardant barrier, and further improve the flame retardant performance of the wire.

[0032] In this invention, the vinyl silane coupling agent is composed of vinyl phenyl silane coupling agent and vinyl benzylamino silane coupling agent. The vinyl phenyl silane coupling agent contains a rigid aromatic phenyl group, which is not easily thermally decomposed during high-temperature combustion. It can form a rigid carbon skeleton support structure inside the char layer. After the phenyl group is introduced, it can be interspersed in the char layer, improving the overall strength and density of the char layer. The char layer is not easily damaged or detached, and can maintain a protective barrier against open flames and inhibit the flow of molten droplets for a long time, preventing the flame from continuously eroding the cable. Simultaneously, the phenyl group has a certain degree of temperature resistance, reducing the char layer thickness at high temperatures. The problem of fracture failure exists; however, the number of benzene rings should not be too high, otherwise the overall heat resistance rigidity of the system will be too high, which will easily lead to surface cracking and brittle fracture defects. Cracks will become channels for heat and oxygen to penetrate inward. At the same time, a large number of rigid benzene rings will increase the viscosity of the flame retardant extrusion process, destroy the uniformity of the sheath wall thickness, and thus affect the improvement of the flame retardant performance of the wire. The vinylbenzylaminosilane coupling agent contains amino active groups, which are organic nitrogen-containing active groups. This nitrogen component can form a flame retardant system with the phosphorus-based aluminum phosphonate and the boron-based zinc borate in the system, thereby improving the flame retardant performance of the wire.

[0033] In one embodiment of the present invention, aluminum hypophosphite is composed of organic aluminum hypophosphite and inorganic aluminum hypophosphite in a mass ratio of 8 to 10:1, wherein the organic aluminum hypophosphite is diethyl aluminum hypophosphite.

[0034] In this invention, the phosphorus content of organic aluminum hypophosphite is ≥23wt%, and the thermal decomposition temperature is ≥350℃; the phosphorus content of aluminum hypophosphite is ≥40wt%, and the thermal decomposition temperature is ≥280℃. Inorganic aluminum hypophosphite has a low decomposition temperature and can release high-concentration phosphorus-based active components first. Aluminum diethylphosphite has a high decomposition temperature and stronger heat resistance. After the inorganic aluminum hypophosphite is consumed, the organic aluminum hypophosphite continuously and stably releases phosphorus sources, maintains the carbon layer structure for a long time, avoids the high-temperature collapse of the carbon layer, and synergistically improves the flame retardant performance of the electrical wire.

[0035] In one embodiment of the present invention, the compatibilizer is maleic anhydride-grafted polyethylene.

[0036] In this invention, the compatibilizer can enhance the interfacial bonding strength between the matrix material and the flame-retardant powder, making the overall structure of the material more compact. During combustion, it blocks heat and oxygen penetration and, together with the compounded flame-retardant system, forms a complete and stable char layer, thereby improving the flame-retardant performance of the electrical wire.

[0037] In one embodiment of the present invention, the additive is composed of an antioxidant, a lubricant and an ultraviolet absorber in a mass ratio of 2~3:1.5~2:0.5.

[0038] In this invention, the antioxidant includes one or more of antioxidants 1010, 168, and 1076, preferably antioxidant 1010. The antioxidant can inhibit the thermal-oxidative aging and decomposition of the material during high-temperature processing and long-term electrical use, delaying the aging and embrittlement of the sheath, and maintaining the material's stability and flame-retardant properties. The lubricant includes one of polyethylene wax, zinc stearate, and stearic acid, preferably zinc stearate. The lubricant can reduce the extrusion melt viscosity of the material, improve the dispersion effect of inorganic powders, reduce wear on processing equipment, and make the sheath surface smooth and the wall thickness uniform. The ultraviolet absorber includes one of ultraviolet absorbers UV-531, UV-327, and UV-328, preferably UV-531. The ultraviolet absorber can absorb ultraviolet light in outdoor and window-side laying environments, preventing the sheath from aging and cracking due to long-term light exposure, and extending the outdoor service life of the cable.

[0039] In the following examples and comparative examples: Linear low-density polyethylene: Model number DFH-2076; Ethylene-vinyl acetate copolymer: Model EVA 28-6; Maleic anhydride-grafted polyethylene: Type Red is E589; Aluminum hydroxide: average particle size is 800 mesh; Aluminum diethylphosphinate: average particle size is 6 μm; Inorganic aluminum hypophosphite: average particle size is 6μm.

[0040] Example 1 A method for preparing flame-retardant electrical wire includes the following steps: S1. Extruding a cross-linked polyethylene insulation layer over a copper conductor yields a semi-finished product; S2. Mix 60 parts of linear low-density polyethylene, 15 parts of ethylene-vinyl acetate copolymer, 50 parts of flame retardant, 4 parts of maleic anhydride grafted polyethylene, and 2 parts of additives evenly, and extrude the mixture onto the outside of the semi-finished product to obtain flame-retardant fabric wire. The additives consist of antioxidant 1010, zinc stearate, and ultraviolet absorber UV-531 in a mass ratio of 2:1.5:0.5. The preparation method of the flame retardant includes the following steps: 4 parts of composite modifier A are dispersed in 300 parts of anhydrous ethanol, 60 parts of aluminum hydroxide are added, and after mixing for 2 hours, the mixture is dried to obtain composite aluminum hydroxide; 1 part of composite modifier B is dispersed in 75 parts of solvent, 15 parts of aluminum hypophosphite are added, and after mixing for 2 hours, the mixture is dried to obtain composite aluminum hypophosphite; the composite aluminum hydroxide, composite aluminum hypophosphite and 6 parts of zinc borate are mixed to obtain the flame retardant. Composite modifier A is composed of 3-glycidylpropyltrimethoxysilane and stearic acid in a mass ratio of 1:0.8; Composite modifier B is composed of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane and vinylsilane coupling agent in a mass ratio of 5:4, wherein the vinylsilane coupling agent is vinylphenylmethylmethoxysilane. Aluminum hypophosphite is aluminum diethylphosphinate.

[0041] Example 2 A method for preparing flame-retardant electrical wire includes the following steps: S1. Extruding a cross-linked polyethylene insulation layer over a copper conductor yields a semi-finished product; S2. Mix 65 parts of linear low-density polyethylene, 18 parts of ethylene-vinyl acetate copolymer, 55 parts of flame retardant, 5 parts of maleic anhydride grafted polyethylene, and 4 parts of additives evenly, and extrude the mixture onto the outside of the semi-finished product to obtain flame-retardant fabric wire. The additives consist of antioxidant 1010, zinc stearate, and ultraviolet absorber UV-531 in a mass ratio of 2.5:1.8:0.5. The preparation method of the flame retardant includes the following steps: 4.5 parts of composite modifier A are dispersed in 325 parts of anhydrous ethanol, 65 parts of aluminum hydroxide are added, and after mixing for 2 hours, the mixture is dried to obtain composite aluminum hydroxide; 0.9 parts of composite modifier B are dispersed in 70 parts of solvent, 12 parts of aluminum hypophosphite are added, and after mixing for 2 hours, the mixture is dried to obtain composite aluminum hypophosphite; the composite aluminum hydroxide, composite aluminum hypophosphite and 6 parts of zinc borate are mixed to obtain the flame retardant. Composite modifier A is composed of 3-glycidylpropyltrimethoxysilane and stearic acid in a mass ratio of 1.2:0.8; Composite modifier B is composed of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane and vinylsilane coupling agent in a mass ratio of 6:4, wherein the vinylsilane coupling agent is vinylphenylmethylmethoxysilane. Aluminum hypophosphite is aluminum diethylphosphinate.

[0042] Example 3 A method for preparing flame-retardant electrical wire includes the following steps: S1. Extruding a cross-linked polyethylene insulation layer over a copper conductor yields a semi-finished product; S2. Mix 70 parts of linear low-density polyethylene, 20 parts of ethylene-vinyl acetate copolymer, 60 parts of flame retardant, 6 parts of maleic anhydride grafted polyethylene, and 5 parts of additives evenly, and extrude the mixture onto the outside of the semi-finished product to obtain flame-retardant fabric wire. The additives consist of antioxidant 1010, zinc stearate, and ultraviolet absorber UV-531 in a mass ratio of 3:2:0.5. The preparation method of the flame retardant includes the following steps: 5 parts of composite modifier A are dispersed in 350 parts of anhydrous ethanol, 70 parts of aluminum hydroxide are added, and after mixing for 2 hours, the mixture is dried to obtain composite aluminum hydroxide; 0.8 parts of composite modifier B are dispersed in 50 parts of solvent, 10 parts of aluminum hypophosphite are added, and after mixing for 2 hours, the mixture is dried to obtain composite aluminum hypophosphite; the composite aluminum hydroxide, composite aluminum hypophosphite and 6 parts of zinc borate are mixed to obtain the flame retardant. Composite modifier A is composed of 3-glycidylpropyltrimethoxysilane and stearic acid in a mass ratio of 1.5:0.8; Composite modifier B is composed of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane and vinylsilane coupling agent in a mass ratio of 8:4, wherein the vinylsilane coupling agent is vinylphenylmethylmethoxysilane. Aluminum hypophosphite is aluminum diethylphosphinate.

[0043] Example 4 The difference between Example 4 and Example 2 is that the vinyl silane coupling agent is diphenylvinylethoxysilane.

[0044] Example 5 The difference between Example 5 and Example 2 is that the vinyl silane coupling agent is methyl vinyl dimethoxysilane.

[0045] Example 6 The difference between Example 6 and Example 2 is that the vinyl silane coupling agent is vinylbenzylaminoethylaminopropyltrimethoxysilane.

[0046] Example 7 The difference between Example 7 and Example 2 is that the vinyl silane coupling agent is composed of vinylphenyl methyl methoxysilane and vinylbenzylaminoethylaminopropyltrimethoxysilane in a mass ratio of 2:1.

[0047] Example 8 The difference between Example 8 and Example 2 is that the vinyl silane coupling agent is composed of vinylphenyl methyl methoxysilane and vinylbenzylaminoethylaminopropyltrimethoxysilane in a mass ratio of 2.5:1.

[0048] Example 9 The difference between Example 9 and Example 8 is that the aluminum hypophosphite is inorganic aluminum hypophosphite.

[0049] Example 10 The difference between Example 10 and Example 8 is that the aluminum hypophosphite is composed of aluminum diethylphosphite and inorganic aluminum hypophosphite in a mass ratio of 8:1.

[0050] Example 11 The difference between Example 11 and Example 8 is that the aluminum hypophosphite is composed of aluminum diethylphosphite and inorganic aluminum hypophosphite in a mass ratio of 10:1.

[0051] Comparative Example 1 Compared with Example 2, Comparative Example 1 differs in that the composite modifier B is composed of 3-glycidylpropyltrimethoxysilane and stearic acid in a mass ratio of 1.2:0.8.

[0052] Comparative Example 2 Compared with Example 2, Comparative Example 2 differs in that the composite modifier A is composed of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane and vinylsilane coupling agent in a mass ratio of 6:4, and the vinylsilane coupling agent is vinylphenylmethylmethoxysilane.

[0053] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that the composite modifier A is 3-glycidylpropyltrimethoxysilane.

[0054] Comparative Example 4 Compared with Example 2, Comparative Example 4 differs in that the composite modifier B is 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane.

[0055] Experimental Example 1 The sheathing layers of the flame-retardant electrical wires prepared in Examples 1-11 and Comparative Examples 1-4 were tested for oxygen index according to the test method specified in GB / T 2406.2-2009 "Determination of flammability by oxygen index method for plastics - Part 2: Room temperature test"; wherein the sample shape was a type IV sample, the sample size was 100mm×6mm×3mm, and the ignition method was method A.

[0056] The test results are shown in Table 1: Table 1 Performance test results of Examples 1-11 and Comparative Examples 1-4

[0057] As shown in Table 1, when the flame retardant in the sheath layer of the electrical wire includes composite modifier A and composite modifier B, and their compositions are different, it helps to improve the flame retardant performance of the electrical wire. When composite modifier A is composed of glycidyl ether type epoxy silane coupling agent and stearic acid, and composite modifier B is composed of alicyclic epoxy silane coupling agent and vinyl silane coupling agent, the resulting electrical wire has a better flame retardant effect. When aluminum phosphinate is composed of organic aluminum phosphinate and inorganic aluminum phosphinate, it can further improve the flame retardant performance of the electrical wire.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flame-retardant electrical wire, comprising a conductor, an insulation layer, and a sheath layer arranged sequentially from the inside out, characterized in that, The sheath layer comprises the following raw materials in parts by weight: 60-70 parts of linear low-density polyethylene, 15-20 parts of ethylene-vinyl acetate copolymer, 50-60 parts of flame retardant, 4-6 parts of compatibilizer, and 2-5 parts of additives. The flame retardant comprises the following raw materials in parts by weight: 60-70 parts of aluminum hydroxide, 10-15 parts of aluminum phosphonate, 6-8 parts of zinc borate, 4-5 parts of composite modifier A, and 0.8-1 parts of composite modifier B. The composite modifier A and the composite modifier B have different compositions.

2. The flame-retardant electrical wire according to claim 1, characterized in that, The conductor is made of copper.

3. The flame-retardant electrical wire according to claim 1, characterized in that, The insulation layer is a cross-linked polyethylene insulation layer.

4. The flame-retardant electrical wire according to claim 1, characterized in that, The composite modifier A is composed of a glycidyl ether type epoxy silane coupling agent and stearic acid in a mass ratio of 1~1.5:0.8; the glycidyl ether type epoxy silane coupling agent includes one or two of 3-glycidylpropyltrimethoxysilane and 3-glycidyl etheroxypropyltriethoxysilane.

5. The flame-retardant electrical wire according to claim 1, characterized in that, The composite modifier B is composed of an alicyclic epoxy silane coupling agent and a vinyl silane coupling agent in a mass ratio of 5~8:

4.

6. The flame-retardant electrical wire according to claim 5, characterized in that, The alicyclic epoxy silane coupling agent is 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, and the vinyl silane coupling agent is composed of vinylphenyl silane coupling agent and vinylbenzylamino silane coupling agent in a mass ratio of 2~2.5:

1.

7. The flame-retardant electrical wire according to claim 6, characterized in that, The vinylphenyl silane coupling agent includes one or both of vinylphenyl methyl methoxysilane and diphenyl vinylethoxysilane, and the vinylbenzylaminosilane coupling agent is vinylbenzylaminoethylaminopropyltrimethoxysilane.

8. The flame-retardant electrical wire according to claim 1, characterized in that, The preparation method of the flame retardant includes the following steps: dispersing composite modifier A in a solvent, adding aluminum hydroxide, mixing and drying to obtain modified aluminum hydroxide; dispersing composite modifier B in a solvent, adding aluminum hypophosphite, mixing and drying to obtain modified aluminum hypophosphite; and mixing the modified aluminum hydroxide, the modified aluminum hypophosphite and the zinc borate to obtain the flame retardant.

9. The flame-retardant electrical wire according to claim 1, characterized in that, The aluminum hypophosphite is composed of organic aluminum hypophosphite and inorganic aluminum hypophosphite in a mass ratio of 8 to 10:1, wherein the organic aluminum hypophosphite is diethyl aluminum hypophosphite.

10. A flame-retardant electrical wire according to claim 1, characterized in that, The compatibilizer is maleic anhydride-grafted polyethylene. The additives consist of antioxidants, lubricants, and ultraviolet absorbers in a mass ratio of 2~3:1.5~2:0.5.

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