High-temperature-resistant flame-retardant cable material and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant flame-retardant cable material and a preparation method thereof, and relates to the technical field of cable processing. The method comprises the following steps: firstly, extruding an insulating material on the surface of a conductor material to form an insulating layer with the thickness of 2-3mm to obtain a wire core; wrapping the surface of the wire core with a copper strip in a spiral winding manner to form a shielding layer with the thickness of 0.3-0.5 mm, so as to obtain a cable core material; the high-temperature-resistant flame-retardant cable material is prepared by the following steps: preparing a cable core material, extruding an insulating material on the surface of the cable core material to form a secondary sheath layer with the thickness of 1-2mm, coating a sheath layer material on the surface of the secondary sheath layer, and curing to form an outer sheath layer with the thickness of 0.8-1mm, thereby obtaining the high-temperature-resistant flame-retardant cable material. According to the invention, the secondary sheath layer effectively improves the insulating and flame-retardant capabilities of the cable material; and the solution A and other components in the sheath layer material are introduced, so that the high temperature resistance and flame retardance of the cable are further improved. Therefore, the cable material disclosed by the invention has a wider application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of cable processing, and in particular to a high-temperature resistant and flame-retardant cable material and a preparation method thereof. Background Art

[0002] A cable is an electrical device used to transmit electrical energy, electrical signals, and achieve electromagnetic energy conversion. It consists of four parts: a conductor, an insulation layer, a shielding layer, and a sheathing layer. The conductor is typically made of a highly conductive metal material and carries current, enabling the transmission of electrical energy or signals. The insulation layer, a material with excellent insulating properties, wraps around the conductor to prevent current leakage and short circuits between conductors, ensuring safe and stable power transmission. The shielding layer, typically made of a metal material, primarily reduces interference from the cable's internal electromagnetic field and prevents external electromagnetic fields from affecting the cable's internal signals, thus ensuring signal transmission quality. The sheathing layer, located at the outermost layer of the cable, primarily provides protection. Cables are widely used in the power, industrial, construction, and communications sectors, resulting in an increasing demand for cables and increasingly demanding performance. For example, cables used in electrical instruments and transmission lines for automatic control systems require enhanced resistance to high temperatures, abrasion, aging, and flame retardancy.

[0003] To improve the cable's resistance to high temperatures and aging, patent document CN117894517B provides a high-temperature and aging-resistant cable and its preparation method. The cable comprises a cable sheath and a conductor material encased in the cable sheath. The sheath is sequentially provided with an insulation layer, a high-temperature resistant layer, and an aging-resistant layer, wherein the insulation layer is coated with the high-temperature resistant layer, and the high-temperature resistant layer is coated with the aging-resistant layer. The high-temperature resistant layer is filled with expanded graphite, and the aging-resistant layer is filled with a hydrophobic fiber material. However, the high-temperature resistance, wear resistance, aging resistance, and flame retardancy of cables prepared by these existing methods still need to be improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a high temperature resistant flame retardant cable material and a preparation method thereof, to solve the following technical problems: Existing cables still have problems with high temperature resistance, aging resistance, and flame retardancy.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing a high-temperature resistant flame-retardant cable material comprises the following steps: Step S1: Extruding an insulating material on the surface of the conductor material to form an insulating layer with a thickness of 2-3 mm to obtain a wire core; Step S2: Wrapping a copper tape on the surface of the cable core in a spiral manner to form a shielding layer with a thickness of 0.3-0.5 mm to obtain a cable core material; Step S3: Extruding insulating material on the surface of the cable core material to form a secondary sheath layer with a thickness of 1-2 mm, then coating the surface of the secondary sheath layer with a sheath layer material, and curing it at 90-100°C and 18 MPa for 18-20 hours to form an outer sheath layer with a thickness of 0.8-1 mm to obtain a high temperature resistant and flame retardant cable material.

[0006] Preferably, the method for preparing the insulating material in step S1 is as follows: The polyvinyl chloride resin, bisphenol A epoxy resin and ethylene-vinyl acetate copolymer are kneaded for 5-7 minutes, and then flame retardant, antioxidant 330 and silane coupling agent KH-550 are added and kneaded for 8-10 minutes, and then added to an extruder and extruded into granules to obtain an insulating material; The usage ratio of the polyvinyl chloride resin, bisphenol A epoxy resin, ethylene-vinyl acetate copolymer, flame retardant, antioxidant 330 and silane coupling agent KH-550 is 500-700g:10-20g:200-300g:5-6mL:10-30g:5-10g.

[0007] Preferably, the preparation method of the flame retardant is as follows: Step A1: Potassium hydroxide, dimethyl sulfoxide, and poly(p-phenylene terephthalamide) fiber are sequentially added to deionized water 1 while stirring. After stirring for 4-5 hours, deionized water 2 is added. After further stirring for 2-3 hours, the mixture is washed and filtered. Deionized water 3 is then added and stirred uniformly to obtain an aqueous dispersion. Step A2: adding dopamine solution and Tris buffer to the aqueous dispersion, stirring at 63-65° C. for 8-10 hours, washing, adding deionized water, and stirring evenly to obtain a modified dispersion; Step A3: Concentrated hydrochloric acid, titanium aluminum carbide, lithium fluoride, and black phosphorene are added to deionized water 4 in sequence, and after stirring, centrifugation, separation, washing, centrifugation, and separation are performed in sequence. Then, deionized water 5 is added to disperse the precipitated substrate, and then ultrasonication, centrifugation, and separation are performed. Finally, the modified dispersion is added to the supernatant, and the flame retardant is obtained after stirring evenly.

[0008] Preferably, the usage ratio of deionized water 1, potassium hydroxide, dimethyl sulfoxide, poly(p-phenylene terephthalamide) fiber, deionized water 2, and deionized water 3 in step A1 is 20-50 mL: 1.5-2 g: 480-700 mL: 1.0-1.5 g: 1000-1500 mL: 100 mL.

[0009] Preferably, the ratio of the aqueous dispersion, dopamine solution, Tris buffer, and deionized water in step A2 is 100 mL: 15-22 mL: 200-300 mL: 5 mL; The concentration of the dopamine solution in step A2 is 2 mg / mL; The pH of the Tris buffer in step A2 is 8.5.

[0010] Preferably, the usage ratio of deionized water 4: concentrated hydrochloric acid, titanium aluminum carbide, lithium fluoride, black phosphorene, deionized water 5, and modified dispersion in step A3 is 2.5-4 mL: 0.5-1.5 mL: 0.5-0.8 g: 0.5-0.8 g: 0.3-0.5 g: 5-6 mL: 5 mL; The mass concentration of concentrated hydrochloric acid in step A3 is 36%-38%; The stirring process in step A3 is performed at a speed of 42-45 rpm and for a duration of 18-20 h. The centrifugation speed in step A3 is 4000-4500 rpm, and the centrifugation time is 30-40 min; The duration of the ultrasound in step A3 is 30-40 minutes, the power is 280-300W, and the frequency is 35-40kHz.

[0011] Preferably, the method for preparing the sheath layer material in step S3 is as follows: Step B1: Vanillin and triethylamine were dissolved in ethyl acetate, followed by dropwise addition of phosphorus oxychloride at 0°C for 30-40 minutes, followed by stirring at 20-25°C for 24-26 hours, followed by addition to deionized water, stirring for 2.5-3.5 hours, and then filtering to remove the solution. The white solid was then recrystallized from ethanol and dried at 68-70°C for 24-26 hours to obtain a white solid; Step B2: dissolving the white solid in chloroform to obtain solution A; Step B3: Add chloroform and 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene to a 1000-2000 mL beaker in sequence, stir for 10-20 minutes, then add 1,4-bis(4-aminophenoxy)benzene, stir for 10-20 minutes, then add solution A, ultrasonically stir at 30°C, and then stir at 60-61°C for 50-60 minutes to obtain a sheath layer material.

[0012] Preferably, the usage ratio of vanillin, triethylamine, ethyl acetate, phosphorus oxychloride, and deionized water in step B1 is 45.6-68.4 g: 30.3-45.4 g: 200-300 mL: 15.3-22.9 g: 900-1500 mL.

[0013] Preferably, the mass ratio of the white solid to chloroform in step S2 is 40-60 g:400-600 g.

[0014] Preferably, in step S3, the usage ratio of chloroform, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, and solution A is 300-450 g: 25.6-38.4 g: 17.5-26.2 g: 440-660 g; The ultrasonic stirring in step S3 lasts for 40-50 minutes, has a power of 280-300 W, and a frequency of 25-35 kHz.

[0015] As a further embodiment of the present invention.

[0016] Beneficial effects of the present invention: The present invention provides a high-temperature resistant and flame-retardant cable material and a preparation method thereof. The present invention effectively improves the high-temperature resistance, aging resistance and flame retardancy of the cable material through the following method.

[0017] (1) The black phosphorene contained in the homemade flame retardant of the present invention can form a phosphorus oxide covering layer during the combustion process, isolating the transfer of oxygen and heat; titanium aluminum carbide and lithium fluoride may participate in the reaction and promote the formation of the carbonized layer, thereby effectively suppressing the spread of flames and improving the flame retardant grade of the insulating material.

[0018] Compared to inorganic flame retardants such as sodium hydroxide, components such as black phosphorene in the self-made flame retardant of the present invention may reduce the intensity of the combustion reaction by endothermic reactions and capturing free radicals, thereby reducing the rapid release of heat. They can also be evenly dispersed and have a good bond with the matrix resin, enhancing the rigidity of the material to a certain extent. At the same time, they can undergo chemical reactions at high temperatures to form stable compounds, preventing further breakage and decomposition of the polymer molecular chains, thereby allowing the material to maintain certain performance at higher temperatures. The addition of a specific proportion of flame retardant can also enhance the cross-linking structure of the material and increase the rigidity of the molecular chain, which may increase the heat deformation temperature.

[0019] (2) In the preparation process of the sheath material of the present invention, a specific proportion of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene and solution A will form a uniform and dense cross-linked network. Slowly adding a specific amount of trifluoromethyl will give the polymer a certain rigidity, increase the flexibility of the molecular chain, and increase the thermal decomposition temperature of the sheath material, so that the tensile strength and toughness of the material can achieve a better balance. The cross-linked structure of the polymer formed by the reaction of vanillin and phosphorus oxychloride after reacting with the amino compound can effectively prevent the movement and decomposition of the molecular chain at high temperature, thereby improving the thermal stability of the material and giving the material a suitable hardness. When the proportions of the raw materials are appropriate, a cross-linked network is formed. Moreover, at a specific proportion, the components will also produce a synergistic effect, effectively preventing the spread of flames, reducing the heat and smoke generated by combustion, maintaining integrity for a certain period of time, preventing flames and heat from being transferred to the interior of the cable, and improving the flame retardant properties of the sheath material.

[0020] (3) The insulation layer and the secondary sheath layer of the specific thickness of the present invention both play the role of electrical insulation and mechanical protection. Therefore, the design of the two-layer insulation structure of the present invention can provide higher insulation reliability and reduce the damage to the conductor caused by external physical impact, friction, etc., while not affecting heat dissipation; the outer sheath layer has stronger mechanical protection ability, high temperature resistance and flame retardant properties. When a fire occurs, it will form a dense carbon layer after burning, and the large amount of phosphorus and nitrogen elements in the carbon layer can greatly protect the internal structure from being damaged, thereby effectively preventing the spread of flames and reducing fire losses. As the outermost structure of the cable, it is in direct contact with the external environment and can also resist external force damage such as wear, cutting, and puncture, thereby extending the service life of the cable.

[0021] Therefore, the high-temperature resistant and flame-retardant cable material prepared by the present invention has more excellent high-temperature resistance, aging resistance, and flame retardancy, as well as broad application prospects. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0023] The properties and sources of some raw materials in the present invention are as follows: Polyvinyl chloride resin was purchased from Hangzhou Hengquan Technology Development Co., Ltd., CAS: 9005-09-8; bisphenol A epoxy resin was purchased from Jiangsu Congzhong Chemical Co., Ltd., CAS: 25085-99-8; ethylene-vinyl acetate copolymer was purchased from Wuhan Xinxin Jiali Biotechnology Co., Ltd., CAS: 74937-78-8; antioxidant 330 (purity 99%) was purchased from Hubei Guangao Biotechnology Co., Ltd., CAS: 1709-70-2; silane coupling agent KH-550 (purity 99%) was purchased from Hubei Shixing Chemical Co., Ltd., CAS: 919-30-2; poly(p-phenylene terephthalamide) fiber (analytical grade) was produced by DuPont Co., Ltd., USA.

[0024] Example 1: A method for preparing a high-temperature resistant flame-retardant cable material is as follows: S1: 1.5 g potassium hydroxide, 480 mL dimethyl sulfoxide, and 1.0 g poly(p-phenylene terephthalamide) fiber were added to 20 mL deionized water while stirring. After stirring for 4 h, 1000 mL deionized water was added. After stirring for another 2 h, the mixture was washed twice and filtered. 100 mL deionized water was then added and stirred to obtain an aqueous dispersion. S2: Add 15 mL of 2 mg / mL dopamine solution and 200 mL of Tris buffer with a pH of 8.5 to 100 mL of aqueous dispersion, stir at 63°C for 8 h, wash with deionized water three times, add 5 mL of deionized water, and stir evenly to obtain a modified dispersion; S3: 0.5 mL of concentrated hydrochloric acid with a mass concentration of 36%, 0.5 g of titanium aluminum carbide, 0.5 g of lithium fluoride, and 0.3 g of black phosphorene were added to 2.5 mL of deionized water in sequence, and the mixture was stirred at 42 rpm for 18 h, followed by centrifugation at a speed of 4000 rpm for 30 min to separate the precipitated substrate, and the separated precipitated substrate was washed with deionized water to a pH of 7, and centrifuged at a speed of 4000 rpm for 30-40 min to separate the precipitated substrate. 5 mL of deionized water was then added to disperse the precipitated substrate, and the mixture was subjected to ultrasonic treatment for 30 min at a power of 280 W and a frequency of 35 kHz at a speed of 4000 rpm to separate the supernatant. Finally, 5 mL of modified dispersion was added to the supernatant, and the mixture was stirred evenly to obtain a flame retardant; S4: 500 g of polyvinyl chloride resin, 10 g of bisphenol A epoxy resin and 200 g of ethylene-vinyl acetate copolymer were kneaded for 5 min, and then 5 mL of flame retardant, 10 g of antioxidant 330 and 5 g of silane coupling agent KH-550 were added and kneaded for 8 min. The mixture was then added to an extruder and extruded into granules to obtain an insulating material. S5: 45.6 g of vanillin and 30.3 g of triethylamine were dissolved in 200 mL of ethyl acetate, and then 15.3 g of phosphorus oxychloride was added dropwise at 0°C for 3 h and reacted for 30 min. The mixture was stirred at 20°C for 24 h, and then added to 900 mL of deionized water and stirred for 2.5 h. The solution was then filtered off and the white solid was recrystallized from ethanol and dried at 68°C for 24 h to obtain a white solid. S6: Dissolve 40 g of the white solid in 400 g of chloroform to obtain solution A; S7: In a 1000 mL beaker, 300 g of chloroform and 25.6 g of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene were added in sequence, and the mixture was stirred for 10 min. Then, 17.5 g of 1,4-bis(4-aminophenoxy)benzene was added, and the mixture was stirred for 10 min. Then, 440 g of solution A was added, and ultrasonic stirring was performed at 30° C. for 40 min, a power of 280 W, and a frequency of 25 kHz, and then stirred at 60° C. for 50 min to obtain a sheath layer material. S8: Extruding an insulating material on the surface of the conductor material to form an insulating layer with a thickness of 2 mm to obtain a wire core; wherein the conductor material is a copper wire bundle formed by twisting five copper wires with a diameter of 1 mm; S9: Wrapping a copper tape on the surface of the wire core in a spiral manner to form a shielding layer with a thickness of 0.3 mm to obtain a cable core material; S10: Extruding an insulating material on the surface of the cable core material to form a secondary sheath layer with a thickness of 1 mm, then coating the surface of the secondary sheath layer with a sheath layer material, and curing it at 90°C and 18 MPa for 18 hours to form an outer sheath layer with a thickness of 0.8 mm, thereby obtaining a high temperature resistant and flame retardant cable material.

[0025] Example 2: A method for preparing a high-temperature resistant flame-retardant cable material is as follows: S1: 1.8 g potassium hydroxide, 590 mL dimethyl sulfoxide, and 1.3 g poly(p-phenylene terephthalamide) fiber were added to 35 mL deionized water while stirring. After stirring for 4.5 h, 1300 mL deionized water was added. After stirring for 2.5 h, the mixture was washed twice and filtered. Then, 100 mL deionized water was added and stirred until uniform to obtain an aqueous dispersion. S2: 19 mL of 2 mg / mL dopamine solution and 250 mL of pH 8.5 Tris buffer were added to 100 mL of aqueous dispersion, stirred at 64°C for 9 h, washed with deionized water four times, and then 5 mL of deionized water was added. The mixture was stirred evenly to obtain a modified dispersion. S3: 1 mL of concentrated hydrochloric acid with a mass concentration of 37%, 0.65 g of titanium aluminum carbide, 0.65 g of lithium fluoride, and 0.4 g of black phosphorene were added to 3.5 mL of deionized water in sequence, and the mixture was stirred at 43 rpm for 19 h, followed by centrifugation at a speed of 4300 rpm for 35 min to separate the precipitated substrate, and the separated precipitated substrate was washed with deionized water to a pH of 7, and centrifuged at a speed of 4300 rpm for 35 min to separate the precipitated substrate. Then, 5.5 mL of deionized water was added to disperse the precipitated substrate, and then the mixture was ultrasonically treated for 35 min at a power of 290 W and a frequency of 38 kHz at a speed of 4300 rpm to separate the supernatant. Finally, 5 mL of modified dispersion was added to the supernatant, and the mixture was stirred evenly to obtain a flame retardant; S4: 600 g of polyvinyl chloride resin, 15 g of bisphenol A epoxy resin and 250 g of ethylene-vinyl acetate copolymer were kneaded for 6 min, and then 5.5 mL of flame retardant, 20 g of antioxidant 330 and 8 g of silane coupling agent KH-550 were added and kneaded for 9 min. The mixture was then added to an extruder and extruded into granules to obtain an insulating material. S5: Dissolve 52 g of vanillin and 37 g of triethylamine in 250 mL of ethyl acetate, then add 19.1 g of phosphorus oxychloride dropwise at 0°C for 3.5 h and react for 35 min. Then, stir and react at 23°C for 25 h. Then, add to 1200 mL of deionized water and stir for 3 h. After that, filter and remove the solution. Then, recrystallize the white solid from ethanol and dry at 69°C for 25 h to obtain a white solid. S6: Dissolve 50 g of the white solid in 500 g of chloroform to obtain solution A; S7: In a 1500 mL beaker, 375 g of chloroform and 32 g of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene were added in sequence, and the mixture was stirred for 15 min. Then, 22 g of 1,4-bis(4-aminophenoxy)benzene was added, and the mixture was stirred for 15 min. Then, 550 g of solution A was added, and ultrasonic stirring was performed at 30°C for 45 min, with a power of 290 W and a frequency of 30 kHz, and then stirred at 60.5°C for 55 min to obtain a sheath layer material. S8: Extruding an insulating material on the surface of the conductor material to form an insulating layer with a thickness of 2.5 mm to obtain a wire core; wherein the conductor material is a copper wire bundle formed by twisting 8 copper wires with a diameter of 1.5 mm; S9: Wrapping a copper tape on the surface of the wire core in a spiral manner to form a shielding layer with a thickness of 0.4 mm to obtain a cable core material; S10: Extruding an insulating material on the surface of the cable core material to form a secondary sheath layer with a thickness of 1.5 mm, then coating the surface of the secondary sheath layer with a sheath layer material, and curing it at 95°C and 18 MPa for 19 hours to form an outer sheath layer with a thickness of 0.9 mm, thereby obtaining a high temperature resistant and flame retardant cable material.

[0026] Example 3: A method for preparing a high-temperature resistant flame-retardant cable material is as follows: S1: 2 g of potassium hydroxide, 700 mL of dimethyl sulfoxide, and 1.5 g of poly(p-phenylene terephthalamide) fiber were added to 50 mL of deionized water while stirring. After stirring for 5 h, 1500 mL of deionized water was added. After stirring for 3 h, the mixture was washed three times and filtered. Then, 100 mL of deionized water was added and stirred until uniform to obtain an aqueous dispersion. S2: Add 22 mL of 2 mg / mL dopamine solution and 300 mL of Tris buffer with a pH of 8.5 to 100 mL of aqueous dispersion, stir at 65°C for 10 h, wash with deionized water five times, add 5 mL of deionized water, and stir evenly to obtain a modified dispersion; S3: 1.5 mL of 38% concentrated hydrochloric acid, 0.8 g of titanium aluminum carbide, 0.8 g of lithium fluoride, and 0.5 g of black phosphorene were added to 4 mL of deionized water in sequence, and the mixture was stirred at 45 rpm for 20 h, followed by centrifugation at 4500 rpm for 40 min to separate the precipitated substrate, and the separated precipitated substrate was washed with deionized water to a pH of 7, and centrifuged at 4500 rpm for 40 min to separate the precipitated substrate. 6 mL of deionized water was then added to disperse the precipitated substrate, and the mixture was ultrasonically treated for 40 min at a power of 300 W and a frequency of 40 kHz at a speed of 4500 rpm to separate the supernatant. Finally, 5 mL of modified dispersion was added to the supernatant, and the mixture was stirred evenly to obtain a flame retardant. S4: 700 g of polyvinyl chloride resin, 20 g of bisphenol A epoxy resin and 300 g of ethylene-vinyl acetate copolymer were kneaded for 7 minutes, and then 6 mL of flame retardant, 30 g of antioxidant 330 and 10 g of silane coupling agent KH-550 were added and kneaded for 10 minutes. The mixture was then added to an extruder and extruded into granules to obtain an insulating material. S5: 68.4 g of vanillin and 45.4 g of triethylamine were dissolved in 300 mL of ethyl acetate, and then 22.9 g of phosphorus oxychloride was added dropwise at 0°C for 4 h and reacted for 40 min. The mixture was stirred at 25°C for 26 h, and then added to 1500 mL of deionized water and stirred for 3.5 h. The solution was then filtered off and the white solid was recrystallized from ethanol and dried at 70°C for 26 h to obtain a white solid. S6: Dissolve 60 g of the white solid in 600 g of chloroform to obtain solution A; S7: In a 2000 mL beaker, 450 g of chloroform and 38.4 g of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene were added in sequence, and the mixture was stirred for 20 min. Then, 26.2 g of 1,4-bis(4-aminophenoxy)benzene was added, and the mixture was stirred for 20 min. Then, 660 g of solution A was added. Ultrasonic stirring was performed at 30° C. for 50 min, a power of 300 W, and a frequency of 35 kHz, and then the mixture was stirred at 61° C. for 60 min to obtain a sheath layer material. S8: Extruding an insulating material on the surface of the conductor material to form an insulating layer with a thickness of 3 mm to obtain a wire core; wherein the conductor material is a copper wire bundle formed by twisting 10 copper wires with a diameter of 5 mm; S9: Wrapping a copper tape on the surface of the wire core in a spiral manner to form a shielding layer with a thickness of 0.5 mm to obtain a cable core material; S10: Extruding an insulating material on the surface of the cable core material to form a secondary sheath layer with a thickness of 2 mm, then coating the surface of the secondary sheath layer with a sheath layer material, and curing it at 100°C and 18 MPa for 20 hours to form an outer sheath layer with a thickness of 1 mm, thereby obtaining a high temperature resistant and flame retardant cable material.

[0027] Comparative Example 1: Compared with Example 1, this comparative example only replaces the "0.5g titanium aluminum carbide, 0.5g lithium fluoride, 0.3g black phosphorene" added during the preparation of the flame retardant with "0.65g titanium aluminum carbide, 0.65g lithium fluoride". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a high-temperature resistant flame-retardant cable material is obtained.

[0028] Comparative Example 2: Compared with Example 1, this comparative example only replaces the "5 mL flame retardant" added during the preparation of the insulating material with "3 g sodium hydroxide", and the remaining steps and parameters are the same. This comparative example will not be repeated, and finally a high-temperature resistant flame-retardant cable material is obtained.

[0029] Comparative Example 3: Compared with Example 1, this comparative example only replaces the step of "kneading 500g of polyvinyl chloride resin, 10g of bisphenol A epoxy resin and 200g of ethylene-vinyl acetate copolymer for 5min, and then adding 5mL of flame retardant, 10g of antioxidant 330, and 5g of silane coupling agent KH-550 and mixing for 8min" in the preparation process of the insulating material with "kneading 200g of polyvinyl chloride resin, 10g of bisphenol A epoxy resin and 500g of ethylene-vinyl acetate copolymer for 5min, and then adding 5mL of flame retardant, 10g of antioxidant 330, and 5g of silane coupling agent KH-550 and mixing for 8min". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a high temperature resistant flame retardant cable material is obtained.

[0030] Comparative Example 4: Compared with Example 1, this comparative example only replaces the "300g chloroform, 25.6g of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, stirring for 10min, adding 17.5g of 1,4-bis(4-aminophenoxy)benzene, stirring for 10min and then adding 440g of solution A" in the preparation process of the sheath layer material with "300g chloroform, 25.6g of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, stirring for 10min, adding 17.5g of 1,4-bis(4-aminophenoxy)benzene, stirring for 10min and then adding 110g of solution A". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a high temperature resistant flame retardant cable material is obtained.

[0031] Comparative Example 5: Compared with Example 1, this comparative example only replaces the "300g chloroform, 25.6g of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, stirring for 10min, adding 17.5g of 1,4-bis(4-aminophenoxy)benzene, stirring for 10min and then adding 440g of solution A" in the preparation process of the sheath layer material with "300g chloroform, 17.5g of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, stirring for 10min, adding 25.6g of 1,4-bis(4-aminophenoxy)benzene, stirring for 10min and then adding 440g of solution A". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, a high temperature resistant flame retardant cable material is obtained.

[0032] Comparative Example 6: Compared with Example 1, this comparative example only replaces the "extruding insulating material on the surface of the cable core material to form a secondary sheath layer with a thickness of 1 mm, and then coating the sheath layer material on the surface of the secondary sheath layer, and curing it at 90°C and 18 MPa for 18 hours to form an outer sheath layer with a thickness of 0.8 mm" in the preparation process of the high-temperature resistant flame-retardant cable material in S10 with "coating the sheath layer material on the surface of the cable core material, and curing it at 90°C and 18 MPa for 18 hours to form an outer sheath layer with a thickness of 1.8 mm" in S10. The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, the high-temperature resistant flame-retardant cable material is obtained.

[0033] Comparative Example 7: Compared with Example 1, this comparative example only replaces the step of "extruding insulating material on the surface of the cable core material to form a secondary sheath layer with a thickness of 1 mm, then coating the sheath layer material on the surface of the secondary sheath layer, and curing at 90°C and 18 MPa for 18 hours to form a sheath layer with a thickness of 0.8 mm" in the preparation process of the high-temperature resistant flame-retardant cable material of S10 with "extruding insulating material on the surface of the cable core material to form a secondary sheath layer with a thickness of 1.8 mm". The remaining steps and parameters are the same and will not be repeated in this comparative example. Finally, the high-temperature resistant flame-retardant cable material is obtained.

[0034] Performance testing: Determination of high temperature resistance: With reference to GB / T19216.21-2003 "Electric Cable and Optical Cable Line Integrity Burning Test" standard, the rated voltage was set to 0.6 / 1KV, and the high temperature resistance of the high temperature resistant flame retardant cable materials prepared in Examples 1 to 3 and Comparative Examples 1 to 7 were measured respectively. The time (h) during which the cable materials remained intact at 950°C was recorded. The test results are shown in Table 1.

[0035] Determination of limiting oxygen index: The high temperature resistant flame retardant cable materials prepared in Examples 1 to 3 and Comparative Examples 1 to 7 were tested for limiting oxygen index (%). The test results are shown in Table 1.

[0036] Determination of aging resistance: With reference to GB / T2951.12-2008 "General test methods for insulation and sheathing materials of electric cables and optical cables - Part 12: General test methods - Thermal aging test", the high-temperature resistant flame-retardant cable materials prepared in Examples 1 to 3 and Comparative Examples 1 to 7 were tested for aging resistance. The tensile strength retention rate and elongation at break retention rate (%) of the cable materials after aging at 150°C for 480 hours were recorded. The test results are shown in Table 1.

[0037] Table 1: Performance test results of Examples 1-3 and Comparative Examples 1-7 Data Analysis: As can be seen from Table 1, the high-temperature resistant flame-retardant cable material prepared by the present invention has high high-temperature resistance, limiting oxygen index, tensile strength retention rate after thermal aging, and elongation at break retention rate after thermal aging, that is, the present invention has excellent high-temperature resistance, flame retardancy and aging resistance.

[0038] This may be due to: (1) The black phosphorene contained in the homemade flame retardant of the present invention can form a phosphorus oxide covering layer during the combustion process, isolating the transfer of oxygen and heat; titanium aluminum carbide and lithium fluoride may participate in the reaction and promote the formation of the carbonized layer, thereby effectively suppressing the spread of flames and improving the flame retardant grade of the insulating material.

[0039] Compared to inorganic flame retardants such as sodium hydroxide, components such as black phosphorene in the self-made flame retardant of the present invention may reduce the intensity of the combustion reaction by endothermic reactions and capturing free radicals, thereby reducing the rapid release of heat. They can also be evenly dispersed and have a good bond with the matrix resin, enhancing the rigidity of the material to a certain extent. At the same time, they can undergo chemical reactions at high temperatures to form stable compounds, preventing further breakage and decomposition of the polymer molecular chains, thereby allowing the material to maintain certain performance at higher temperatures. The addition of a specific proportion of flame retardant can also enhance the cross-linking structure of the material and increase the rigidity of the molecular chain, which may increase the heat deformation temperature.

[0040] (2) In the preparation process of the sheath material of the present invention, a specific proportion of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene and solution A will form a uniform and dense cross-linked network. Slowly adding a specific amount of trifluoromethyl will give the polymer a certain rigidity, increase the flexibility of the molecular chain, and increase the thermal decomposition temperature of the sheath material, so that the tensile strength and toughness of the material can achieve a better balance. The cross-linked structure of the polymer formed by the reaction of vanillin and phosphorus oxychloride after reacting with the amino compound can effectively prevent the movement and decomposition of the molecular chain at high temperature, thereby improving the thermal stability of the material and giving the material a suitable hardness. When the proportions of the raw materials are appropriate, a cross-linked network is formed. Moreover, at a specific proportion, the components will also produce a synergistic effect, effectively preventing the spread of flames, reducing the heat and smoke generated by combustion, maintaining integrity for a certain period of time, preventing flames and heat from being transferred to the interior of the cable, and improving the flame retardant properties of the sheath material.

[0041] (3) The insulation layer and the secondary sheath layer of the specific thickness of the present invention both play the role of electrical insulation and mechanical protection. Therefore, the design of the two-layer insulation structure of the present invention can provide higher insulation reliability and reduce the damage to the conductor caused by external physical impact, friction, etc., while not affecting heat dissipation; the outer sheath layer has stronger mechanical protection ability, high temperature resistance and flame retardant properties. When a fire occurs, it will form a dense carbon layer after burning, and the large amount of phosphorus and nitrogen elements in the carbon layer can greatly protect the internal structure from being damaged, thereby effectively preventing the spread of flames and reducing fire losses. As the outermost structure of the cable, it is in direct contact with the external environment and can also resist external force damage such as wear, cutting, and puncture, thereby extending the service life of the cable.

[0042] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a high temperature resistant flame retardant cable material, characterized in that: The following steps are involved: Step S1: Extruding an insulating material on the surface of the conductor material to form an insulating layer with a thickness of 2-3 mm to obtain a wire core; Step S2: Wrapping a copper tape on the surface of the cable core in a spiral manner to form a shielding layer with a thickness of 0.3-0.5 mm to obtain a cable core material; Step S3: Extruding insulating material on the surface of the cable core material to form a secondary sheath layer with a thickness of 1-2 mm, then coating the surface of the secondary sheath layer with a sheath layer material, and curing it at 90-100°C and 18 MPa for 18-20 hours to form an outer sheath layer with a thickness of 0.8-1 mm to obtain a high temperature resistant and flame retardant cable material.

2. The method for preparing a high temperature resistant flame retardant cable material according to claim 1, characterized in that: The method for preparing the insulating material in step S1 is as follows: The polyvinyl chloride resin, bisphenol A epoxy resin and ethylene-vinyl acetate copolymer are kneaded for 5-7 minutes, and then flame retardant, antioxidant 330 and silane coupling agent KH-550 are added and kneaded for 8-10 minutes, and then added to the extruder and extruded into granules to obtain the insulating material; The usage ratio of the polyvinyl chloride resin, bisphenol A epoxy resin, ethylene-vinyl acetate copolymer, flame retardant, antioxidant 330 and silane coupling agent KH-550 is 500-700g:10-20g:200-300g:5-6mL:10-30g:5-10g.

3. The method for preparing a high temperature resistant flame retardant cable material according to claim 2, characterized in that: The preparation method of the flame retardant is as follows: Step A1: Potassium hydroxide, dimethyl sulfoxide, and poly(p-phenylene terephthalamide) fiber are sequentially added to deionized water 1 while stirring. After stirring for 4-5 hours, deionized water 2 is added. After further stirring for 2-3 hours, the mixture is washed and filtered. Deionized water 3 is then added and stirred uniformly to obtain an aqueous dispersion. Step A2: adding dopamine solution and Tris buffer to the aqueous dispersion, stirring at 63-65° C. for 8-10 hours, washing, adding deionized water, and stirring evenly to obtain a modified dispersion; Step A3: Concentrated hydrochloric acid, titanium aluminum carbide, lithium fluoride, and black phosphorene are added to deionized water 4 in sequence, and after stirring, centrifugation, separation, washing, centrifugation, and separation are performed in sequence. Then, deionized water 5 is added, and ultrasonication, centrifugation, and separation are performed. Finally, the modified dispersion is added to the supernatant, and the flame retardant is obtained after stirring evenly.

4. The method for preparing a high temperature resistant flame retardant cable material according to claim 3, characterized in that: The usage ratio of deionized water 1, potassium hydroxide, dimethyl sulfoxide, poly(p-phenylene terephthalamide) fiber, deionized water 2, and deionized water 3 in step A1 is 20-50 mL: 1.5-2 g: 480-700 mL: 1.0-1.5 g: 1000-1500 mL: 100 mL.

5. The method for preparing a high temperature resistant flame retardant cable material according to claim 3, characterized in that: The ratio of the aqueous dispersion, dopamine solution, Tris buffer, and deionized water in step A2 is 100 mL: 15-22 mL: 200-300 mL: 5 mL; The concentration of the dopamine solution in step A2 is 2 mg / mL; The pH of the Tris buffer in step A2 is 8.

5.

6. The method for preparing a high temperature resistant flame retardant cable material according to claim 3, characterized in that: The usage ratio of deionized water 4: concentrated hydrochloric acid, titanium aluminum carbide, lithium fluoride, black phosphorene, deionized water 5, and modified dispersion in step A3 is 2.5-4 mL: 0.5-1.5 mL: 0.5-0.8 g: 0.5-0.8 g: 0.3-0.5 g: 5-6 mL: 5 mL; The mass concentration of concentrated hydrochloric acid in step A3 is 36%-38%; The stirring process in step A3 is performed at a speed of 42-45 rpm and for a duration of 18-20 h. The centrifugation speed in step A3 is 4000-4500 rpm, and the centrifugation time is 30-40 min; The duration of the ultrasound in step A3 is 30-40 minutes, the power is 280-300W, and the frequency is 35-40kHz.

7. The method for preparing a high temperature resistant flame retardant cable material according to claim 1, characterized in that: The preparation method of the sheath layer material in step S3 is as follows: Step B1: Vanillin and triethylamine were dissolved in ethyl acetate, followed by dropwise addition of phosphorus oxychloride at 0°C for 30-40 minutes, followed by stirring at 20-25°C for 24-26 hours, followed by addition to deionized water, stirring for 2.5-3.5 hours, and then filtering to remove the solution. The white solid was then recrystallized from ethanol and dried at 68-70°C for 24-26 hours to obtain a white solid; Step B2: dissolving the white solid in chloroform to obtain solution A; Step B3: Add chloroform and 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene to a 1000-2000 mL beaker in sequence, stir for 10-20 minutes, then add 1,4-bis(4-aminophenoxy)benzene, stir for 10-20 minutes, then add solution A, ultrasonically stir at 30°C, and then stir at 60-61°C for 50-60 minutes to obtain a sheath layer material.

8. The method for preparing a high temperature resistant flame retardant cable material according to claim 7, characterized in that: In step B1, the usage ratio of vanillin, triethylamine, ethyl acetate, phosphorus oxychloride, and deionized water is 45.6-68.4 g: 30.3-45.4 g: 200-300 mL: 15.3-22.9 g: 900-1500 mL.

9. The method for preparing a high temperature resistant flame retardant cable material according to claim 7, characterized in that: The mass ratio of the white solid to chloroform in step S2 is 40-60 g:400-600 g.

10. The method for preparing a high temperature resistant flame retardant cable material according to claim 7, characterized in that: In step S3, the usage ratio of chloroform, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, and solution A is 300-450 g: 25.6-38.4 g: 17.5-26.2 g: 440-660 g; The ultrasonic stirring in step S3 lasts for 40-50 minutes, has a power of 280-300 W, and a frequency of 25-35 kHz.

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