Ultrafine high-flame-retardant CAT6A signal transmission cable and preparation method thereof

Abstract

The invention relates to the technical field of cable sheaths, and particularly discloses a superfine high-flame-retardant CAT6A signal transmission cable and a preparation method thereof.After a conductor is coated with an insulating HDPE composite material to form an insulating core wire, Kevlar fibers serve as filler and are coated with a polytetrafluoroethylene tape, and a cable core is formed; and finally, the cable core is coated with the flame-retardant TPE composite material, so that the prepared cable is good in flame retardance, can be self-extinguished after being away from fire, is excellent in insulating property, meets the development requirements of the network equipment connection industry, and has the transmission performance of TIA Patch Cord Cat6A 15.0 m signal integrity.

Description

Technical Field

[0001] The present invention relates to the technical field of cable sheaths, and in particular to an ultra-fine high-flame-retardant CAT6A signal transmission cable and a preparation method thereof. Background Art

[0002] Cables are the carriers of signal transmission. The conductors—the cable cores—play a primary role in signal transmission. The cable sheath, which protects the cable core, is equally important. The cable sheath not only protects the cable core from corrosion and oxidation, but polymer materials, due to their excellent mechanical properties, insulation performance, and lightweight weight, offer unique advantages in cable sheathing applications. However, in actual use, polymer sheaths are affected by environmental factors such as electric fields, temperature, and humidity, as well as mechanical stress. Furthermore, defects such as pores and impurities in the material can make them susceptible to partial discharge, which can degrade insulation performance or even lead to insulation breakdown, disrupting the normal transmission of data signals. Therefore, the development of flame-retardant cables with excellent insulation performance plays a crucial role in promoting the development of the network equipment connectivity industry. Summary of the Invention

[0003] The purpose of the present invention is to provide an ultra-fine line highly flame-retardant CAT6A signal transmission cable and a preparation method thereof, so as to solve the problem that the insulation performance and flame retardancy of traditional signal transmission cables are not good enough.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: A method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable, specifically comprising: Step 1: Extruding the insulating HDPE composite material onto the conductor through a core wire extruder to form an insulating core wire; Step 2: Twist two independent insulated core wires together to form a pair of insulated core wires; Step 3: Twist four pairs of insulated core wires together, fill them with Kevlar fiber, and then wrap them with polytetrafluoroethylene tape to form a cable core; Step 4: Extrude the flame-retardant TPE composite material onto the cable core through a sheath extruder to form an extremely fine line highly flame-retardant CAT6A signal transmission cable.

[0005] As a limitation of the present invention, the preparation method of the insulating HDPE composite material is: Mix p-hydroxyacetophenone, allyl bromide, and acetone, stir until completely dissolved, add anhydrous sodium carbonate, react at room temperature for 10 to 14 hours and reflux, add distilled water after the reaction is complete to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, and evaporate the excess solvent to obtain allyloxyacetophenone; High-density polyethylene, maleic anhydride, antioxidant 1010, and benzophenone are uniformly mixed, and kneaded at 130-150° C. for 2-10 minutes. After 2-10 minutes, tripropylene cyanurate, propyleneoxyacetophenone, and composite thermally conductive insulating filler are added, and kneading is continued for 10-15 minutes. After kneading, vulcanization is carried out at 130-150° C. and 0.1-1.0 MPa for 5-10 minutes. After vulcanization, the material is irradiated under ultraviolet light with a wavelength of 365 nm for 5-15 minutes to be cross-linked, and the material is cooled to obtain an insulating HDPE composite material.

[0006] The phenolic hydroxyl group of p-hydroxyacetophenone undergoes a substitution reaction with the carbon-bromine bond of allyl bromide under alkaline conditions to generate allyloxyacetophenone. The carbonyl group on allyloxyacetophenone has a high electron affinity, which can capture carriers and inhibit space charge accumulation; the lone pair of electrons on the allyloxy group forms weak hydrogen bonds with the carbon-hydrogen bonds of the HDPE chain, evenly dispersing the trap energy levels; under ultraviolet light irradiation, the allyl group induces cross-linking between HDPE chains to form a three-dimensional network structure, thereby improving the resistance to electrical dendrite formation.

[0007] As a limitation of the present invention, the insulating HDPE composite material includes, by mass, 35 to 45 parts of high-density polyethylene, 0.35 to 0.45 parts of maleic anhydride, 0.1 to 0.3 parts of antioxidant 1010, 0.5 to 1.0 parts of benzophenone, 0.2 to 0.5 parts of tripropylene cyanurate, 0.1 to 0.3 parts of propenyloxyacetophenone, and 4.0 to 6.0 parts of composite thermally conductive insulating filler; the mass ratio of p-hydroxyacetophenone to allyl bromide is (9 to 11):(12 to 15).

[0008] As a limitation of the present invention, the preparation method of the composite thermally conductive insulating filler is: Alumina hollow spheres are added to hydrochloric acid, ultrasonically treated for 20 to 30 minutes, washed with deionized water, and dried. Boron nitride is added to a mixture of nitric acid and hydrogen peroxide, ultrasonically treated for 40 to 60 minutes, washed with deionized water, and dried. The acid-treated alumina hollow spheres are added to dopamine-Tris buffer, stirred at 25 to 30° C. and 200 to 300 rpm for 1 to 2 hours, and acid-treated boron nitride is added after 1 to 2 hours, and the stirring reaction is continued for 8 to 10 hours. After the reaction is completed, the mixture is filtered, washed with deionized water, and dried at 60 to 70° C. for 3 to 4 hours to obtain a composite thermally conductive insulating filler.

[0009] Dopamine and boron nitride are used as raw materials to generate a coating layer of polydopamine doped with boron nitride on the surface of alumina hollow spheres. The alumina hollow spheres can reduce the density of the material while improving the toughness and high-temperature resistance of the material. The polydopamine shell layer ensures the dispersion and adhesion of the filler in the high-density polyethylene matrix. Boron nitride forms a thermal conductive network in the polydopamine shell layer, ensuring that the insulation of the material is not deteriorated while improving the thermal conductivity of the material.

[0010] As a limitation of the present invention, the mass fraction of the hydrochloric acid is 3% to 8%, the mass ratio of the hollow alumina spheres to the hydrochloric acid is (1 to 2): (5 to 10); the mass fraction of nitric acid in the mixed solution is 3% to 8%, the mass fraction of hydrogen peroxide is 5% to 10%, and the mass ratio of boron nitride to the mixed solution is (1 to 2): (40 to 60); the concentration of dopamine in the dopamine-Tris buffer is 0.1 to 0.3 mg / mL; and the mass ratio of the hollow alumina spheres, boron nitride, and dopamine-Tris buffer is (5 to 10): 1: (90 to 110).

[0011] As a limitation of the present invention, the preparation method of the flame retardant TPE composite material is: Polyethylene, polyphenylene sulfide, and compatibilizer masterbatch are mixed at 70-80°C and 200-300 rpm for 3-7 minutes, and then flame retardant masterbatch, antioxidant 1010, and antioxidant 168 are added. After continuing to mix for 10-15 minutes, the mixture is transferred to an internal mixer. Isopropyl benzene peroxide and triallyl isocyanurate are added to methyl silicone oil, and the mixture is heated to 50-60°C and stirred continuously for 20-30 minutes to dissolve to obtain a mixed solution. Methyl vinyl silane and the mixed solution are added to the internal mixer and mixed at 160-170°C for 3-7 minutes. After the mixing is completed, the mixture is transferred to a screw extruder for extrusion and granulation, and the head temperature is controlled at 140-150°C to obtain a flame-retardant TPE composite material.

[0012] Thermoplastic elastomer (TPE) is composed of polyethylene as the plastic phase and weather-resistant and insulating silicone rubber as the elastic phase. Polyphenylene sulfide is added as a heat-resistant structure to improve the long-term temperature resistance of TPE. Isopropyl benzene peroxide is the main cross-linking agent, and triallyl isocyanurate is the auxiliary cross-linking agent, which helps the silicone rubber in the matrix to cross-link to form a heat-resistant network, thereby improving the temperature resistance and mechanical properties of the composite material. Antioxidants 1010 and 168 work synergistically to enhance the weather resistance of the composite material.

[0013] As a limitation of the present invention, the flame retardant masterbatch is obtained by mixing aluminum hydroxide, mica and EVA wax and then extruding and granulating at 160°C; wherein the mass ratio of aluminum hydroxide, mica and EVA wax is (65-67):(25-28):(5-10).

[0014] Aluminum hydroxide and mica flame-retardant TPE composite materials, when the material burns, aluminum hydroxide decomposes and absorbs heat, releasing water vapor and aluminum oxide. The water vapor captures the free radicals produced during the combustion process; the mica sheet blocks the diffusion of heat and combustible gases; at high temperatures, mica and aluminum oxide react to form a dense, high-temperature resistant ceramic layer, isolating oxygen and combustible gases while maintaining structural integrity and reducing molten dripping. In addition, the silicone rubber in the material burns to form silicon oxide, which participates in the mica ceramic reaction and enhances the strength of the combustion residue.

[0015] As a limitation of the present invention, the compatibilizer masterbatch is obtained by mixing maleic anhydride grafted SEBS and low-density polyethylene, and then extruding and granulating at 180° C.; wherein the mass ratio of maleic anhydride grafted SEBS to low-density polyethylene is (0.7-1.5):1.

[0016] Maleic anhydride grafted SEBS is used as a compatibilizer. The SEBS segment at one end is compatible with PE, and the maleic anhydride at the other end can combine with the end group of polyphenylene sulfide, the silanol group of silicone rubber and the inorganic filler (flame retardant), thereby reducing the interfacial tension between PE and silicone rubber and improving the dispersion of polyphenylene sulfide, silicone rubber and inorganic filler in TPE materials.

[0017] As a limitation of the present invention, the flame retardant TPE composite material includes, by mass, 50 to 60 parts of polyethylene, 17 to 22 parts of polyphenylene sulfide, 15 to 20 parts of compatibilizer masterbatch, 35 to 40 parts of flame retardant masterbatch, 0.3 to 0.5 parts of antioxidant 1010, 0.2 to 0.5 parts of antioxidant 168, 30 to 40 parts of methyl vinyl silane, 0.8 to 1.2 parts of isopropyl peroxide and 0.5 to 1.0 parts of triallyl isocyanurate.

[0018] An ultra-fine wire, highly flame-retardant CAT6A signal transmission cable with a 34AWG conductor diameter and signal integrity transmission performance through the TIAPatch Cord Cat6A 15.0m.

[0019] Compared with the prior art, the present invention has the following beneficial effects: To modify high-density polyethylene, propenyloxyacetophenone and maleic anhydride are grafted onto the polyethylene molecular chain. By introducing a double bond group at the para position of acetophenone to form propenyloxyacetophenone, which is then grafted onto high-density polyethylene, the energy of high-energy electrons can be absorbed through the mutual conversion between the keto form and the enol form of the propenyloxyacetophenone itself, and the energy is released in a harmless manner in the form of light and heat, thereby protecting the polyethylene macromolecular chain; the grafted polar compound maleic anhydride can introduce densely distributed deep traps into the polymer structure. The deep traps capture the injected charges to form a barrier, inhibiting further charge injection, thereby achieving the effect of suppressing space charge.

[0020] Dopamine and boron nitride are used as raw materials to generate a coating layer of polydopamine doped with boron nitride on the surface of alumina hollow spheres. The alumina hollow spheres can reduce the density of the material while improving the toughness and high-temperature resistance of the material. The polydopamine shell layer ensures the dispersion and adhesion of the filler in the high-density polyethylene matrix. Boron nitride forms a thermal conductive network in the polydopamine shell layer, ensuring that the insulation of the material is not deteriorated while improving the thermal conductivity of the material.

[0021] The thermoplastic elastomer (TPE) is composed of polyethylene as the plastic phase and weather-resistant and insulating silicone rubber as the elastic phase. Polyphenylene sulfide is added as a heat-resistant structure to improve the long-term temperature resistance of TPE. Flame retardants composed of aluminum hydroxide and mica are added for flame retardancy. Antioxidants 1010 and 168 are added to improve the weather resistance of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a cross-sectional view of a finished product of an ultra-fine wire highly flame-retardant CAT6A signal transmission cable prepared by the preparation method in Example 1, wherein the conductor in the cable is 34AWG bare stranded copper, the flame-retardant TPE sheath layer of the cable is formed by extruding a flame-retardant TPE composite material through a sheath extruder, and the HDPE insulation layer of the cable is formed by extruding an insulating HDPE composite material through a core wire extruder. DETAILED DESCRIPTION

[0023] 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 some embodiments of the present invention, not all embodiments. 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.

[0024] Conductor (34AWG bare stranded copper, 19 strands, 0.04±0.003mm), Kevlar fiber (1500D), polytetrafluoroethylene tape (7×0.05mm), high-density polyethylene (041-T, 0.96g / cm 3 ), hollow alumina spheres (particle size: 10 μm, wall thickness 500 nm), dopamine-Tris buffer (pH = 8.5, dopamine concentration of 2 mg / mL), antioxidant 1010 (purity: 98%), antioxidant 168 (purity: 98%), low-density polyethylene (MFI = 4.0 g / 10 min), aluminum hydroxide (particle size: 2 ± 1 μm), mica (flake size: 10 ± 5 μm, thickness 0.5-1 μm), EVA wax (VA content: 13%-15%, viscosity CPS@140: 100-200 Pa·s), maleic anhydride grafted SEBS (styrene: 29%, diblock: <1%, MFI = 10.0 g / 10 min).

[0025] Example 1: A method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable, specifically comprising: Step 1: Mix 10 g of p-hydroxyacetophenone, 13.3 g of allyl bromide, and 120 g of acetone, stir until completely dissolved, add 40 g of anhydrous sodium carbonate, react for 12 hours and reflux, add 20 g of distilled water after 12 hours to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, and evaporate the excess solvent to obtain allyloxyacetophenone; Step 2: 10 g of hollow alumina spheres were added to 100 g of 5% hydrochloric acid, ultrasonically treated for 30 min, washed with deionized water, and dried. 2 g of boron nitride was added to a mixture of 30 g of 8% nitric acid and 30 g of 10% hydrogen peroxide, ultrasonically treated for 60 min, washed with deionized water, and dried. The acid-treated hollow alumina spheres were added to a dopamine-Tris buffer solution with a concentration of 2 mg / mL, stirred at 25 ° C and 200 rpm for 2 h, and then the acid-treated boron nitride was added after 2 h. The stirring reaction continued for 10 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried at 60 ° C for 4 h to obtain a composite thermally conductive insulating filler. Step 3: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust the pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermal conductive insulating filler, react at 80°C, 300rpm for 3h, filter after the reaction is completed, wash with ethanol and deionized water, and dry at 80°C for 2h to obtain a composite thermal conductive insulating filler; Step 4: 40g high-density polyethylene, 0.4g maleic anhydride, 0.12g antioxidant 1010, and 0.72g initiator benzophenone were placed in a torque rheometer and mixed at 140°C for 5 minutes. After 5 minutes, 0.4g of a cross-linking agent tripropylene cyanurate, 0.2g of propyleneoxyacetophenone, and 5g of a composite thermally conductive insulating filler were added and mixing continued for 10 minutes. After mixing, vulcanization was performed on a flat vulcanizer at 140°C and 0.5MPa for 5 minutes. After vulcanization, the composite was irradiated under ultraviolet light with a wavelength of 365nm for 10 minutes to crosslink it and cooled to obtain an insulating HDPE composite material; Step 5: Extruding the insulating HDPE composite material onto the conductor through a core wire extruder to form an insulating core wire; Step 6: Twist the two independent insulated core wires together to form a pair of insulated core wires; Step 7: Twist four pairs of insulated core wires together, fill them with Kevlar fiber, and then wrap them with polytetrafluoroethylene tape to form the cable core; Step 8: Dry low-density polyethylene at 80°C for 4 hours, dry polyphenylene sulfide at 150°C for 3 hours, and dry aluminum hydroxide and mica at 200°C for 2 hours. After drying, mix aluminum hydroxide, mica and EVA wax at a mass ratio of 65:30:5, and extrude and granulate at 160°C to obtain a flame retardant masterbatch. Mix maleic anhydride grafted SEBS and low-density polyethylene at a mass ratio of 1:1, and extrude and granulate at 180°C to obtain a compatibilizer masterbatch. Step 9: After mixing 50g of polyethylene, 17g of polyphenylene sulfide, and 16g of compatibilizer masterbatch at 80°C and 300rpm for 5min, 35g of flame retardant masterbatch, 0.3g of antioxidant 1010, and 0.2g of antioxidant 168 were added, and the mixture was transferred to an internal mixer after continuing to mix for 10min. 0.8g of isopropyl peroxide and 0.5g of triallyl isocyanurate were added to 8g of methyl silicone oil, and the mixture was heated to 50°C and stirred continuously for 30min to dissolve to obtain a mixed solution. 30g of methyl vinyl silane and the mixed solution were added to the internal mixer, and the mixture was mixed at 160°C for 5min. After the mixing was completed, the mixture was transferred to a screw extruder for extrusion and granulation, and the head temperature was controlled at 140°C to obtain a flame retardant TPE composite material. Step 10: Extrude the flame-retardant TPE composite material onto the cable core through a sheath extruder to form an extremely fine line highly flame-retardant CAT6A signal transmission cable.

[0026] Example 2: A method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable, specifically comprising: Step 1: Mix 10 g of p-hydroxyacetophenone, 13.3 g of allyl bromide, and 120 g of acetone, stir until completely dissolved, add 40 g of anhydrous sodium carbonate, react for 12 hours and reflux, add 20 g of distilled water after 12 hours to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, and evaporate the excess solvent to obtain allyloxyacetophenone; Step 2: 10 g of hollow alumina spheres were added to 100 g of 5% hydrochloric acid, ultrasonically treated for 30 min, washed with deionized water, and dried. 2 g of boron nitride was added to a mixture of 30 g of 8% nitric acid and 30 g of 10% hydrogen peroxide, ultrasonically treated for 60 min, washed with deionized water, and dried. The acid-treated hollow alumina spheres were added to a dopamine-Tris buffer solution with a concentration of 2 mg / mL, stirred at 25 ° C and 200 rpm for 2 h, and then the acid-treated boron nitride was added after 2 h. The stirring reaction continued for 10 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried at 60 ° C for 4 h to obtain a composite thermally conductive insulating filler. Step 3: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust the pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermal conductive insulating filler, react at 80°C, 300rpm for 3h, filter after the reaction is completed, wash with ethanol and deionized water, and dry at 80°C for 2h to obtain a composite thermal conductive insulating filler; Step 4: 42g of high-density polyethylene, 0.42g of maleic anhydride, 0.2g of antioxidant 1010, and 0.8g of initiator benzophenone were placed in a torque rheometer and mixed at 140°C for 5 minutes. After 5 minutes, 0.4g of a cross-linking agent tripropylene cyanurate, 0.2g of propyleneoxyacetophenone, and 5.5g of a composite thermally conductive insulating filler were added and mixing continued for 10 minutes. After mixing, vulcanization was performed on a flat vulcanizer at 140°C and 0.5MPa for 5 minutes. After vulcanization, the mixture was irradiated under ultraviolet light with a wavelength of 365nm for 10 minutes to crosslink it and cooled to obtain an insulating HDPE composite material; Step 5: Extruding the insulating HDPE composite material onto the conductor through a core wire extruder to form an insulating core wire; Step 6: Twist the two independent insulated core wires together to form a pair of insulated core wires; Step 7: Twist four pairs of insulated core wires together, fill them with Kevlar fiber, and then wrap them with polytetrafluoroethylene tape to form the cable core; Step 8: Dry low-density polyethylene at 80°C for 4 hours, dry polyphenylene sulfide at 150°C for 3 hours, and dry aluminum hydroxide and mica at 200°C for 2 hours. After drying, mix aluminum hydroxide, mica and EVA wax at a mass ratio of 65:30:5, and extrude and granulate at 160°C to obtain a flame retardant masterbatch. Mix maleic anhydride grafted SEBS and low-density polyethylene at a mass ratio of 1:1, and extrude and granulate at 180°C to obtain a compatibilizer masterbatch. Step 9: After mixing 55g of polyethylene, 19g of polyphenylene sulfide, and 18g of compatibilizer masterbatch at 80°C and 300rpm for 5min, 37g of flame retardant masterbatch, 0.3g of antioxidant 1010, and 0.2g of antioxidant 168 were added, and the mixture was transferred to an internal mixer after continuing to mix for 10min. 0.8g of isopropyl peroxide and 0.5g of triallyl isocyanurate were added to 8g of methyl silicone oil, and the mixture was heated to 50°C and stirred continuously for 30min to dissolve to obtain a mixed solution. 35g of methyl vinyl silane and the mixed solution were added to the internal mixer, and the mixture was mixed at 160°C for 5min. After the mixing was completed, the mixture was transferred to a screw extruder for extrusion and granulation, and the head temperature was controlled at 140°C to obtain a flame retardant TPE composite material. Step 10: Extrude the flame-retardant TPE composite material onto the cable core through a sheath extruder to form an extremely fine line highly flame-retardant CAT6A signal transmission cable.

[0027] Example 3: A method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable, specifically comprising: Step 1: Mix 10 g of p-hydroxyacetophenone, 13.3 g of allyl bromide, and 120 g of acetone, stir until completely dissolved, add 40 g of anhydrous sodium carbonate, react for 12 hours and reflux, add 20 g of distilled water after 12 hours to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, and evaporate the excess solvent to obtain allyloxyacetophenone; Step 2: 10 g of hollow alumina spheres were added to 100 g of 5% hydrochloric acid, ultrasonically treated for 30 min, washed with deionized water, and dried. 2 g of boron nitride was added to a mixture of 30 g of 8% nitric acid and 30 g of 10% hydrogen peroxide, ultrasonically treated for 60 min, washed with deionized water, and dried. The acid-treated hollow alumina spheres were added to a dopamine-Tris buffer solution with a concentration of 2 mg / mL, stirred at 25 ° C and 200 rpm for 2 h, and then the acid-treated boron nitride was added after 2 h. The stirring reaction continued for 10 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried at 60 ° C for 4 h to obtain a composite thermally conductive insulating filler. Step 3: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust the pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermal conductive insulating filler, react at 80°C, 300rpm for 3h, filter after the reaction is completed, wash with ethanol and deionized water, and dry at 80°C for 2h to obtain a composite thermal conductive insulating filler; Step 4: 45g of high-density polyethylene, 0.45g of maleic anhydride, 0.25g of antioxidant 1010, and 0.9g of initiator benzophenone were placed in a torque rheometer and mixed at 140°C for 5min. After 5min, 0.4g of co-crosslinking agent tripropylene cyanurate, 0.2g of propyleneoxyacetophenone, and 6g of composite thermal conductive insulating filler were added and mixing was continued for 10min. After mixing, vulcanization was performed on a flat vulcanizer at 140°C and 0.5MPa for 5min. After vulcanization, the composite was irradiated under ultraviolet light with a wavelength of 365nm for 10min to crosslink it and cooled to obtain an insulating HDPE composite material; Step 5: Extruding the insulating HDPE composite material onto the conductor through a core wire extruder to form an insulating core wire; Step 6: Twist the two independent insulated core wires together to form a pair of insulated core wires; Step 7: Twist four pairs of insulated core wires together, fill them with Kevlar fiber, and then wrap them with polytetrafluoroethylene tape to form the cable core; Step 8: Dry low-density polyethylene at 80°C for 4 hours, dry polyphenylene sulfide at 150°C for 3 hours, and dry aluminum hydroxide and mica at 200°C for 2 hours. After drying, mix aluminum hydroxide, mica and EVA wax at a mass ratio of 65:30:5, and extrude and granulate at 160°C to obtain a flame retardant masterbatch. Mix maleic anhydride grafted SEBS and low-density polyethylene at a mass ratio of 1:1, and extrude and granulate at 180°C to obtain a compatibilizer masterbatch. Step 9: After mixing 60g of polyethylene, 22g of polyphenylene sulfide, and 20g of compatibilizer masterbatch at 80°C and 300rpm for 5min, 40g of flame retardant masterbatch, 0.3g of antioxidant 1010, and 0.2g of antioxidant 168 were added, and the mixture was transferred to an internal mixer after continuing to mix for 10min. 0.8g of isopropyl peroxide and 0.5g of triallyl isocyanurate were added to 8g of methyl silicone oil, and the mixture was heated to 50°C and stirred continuously for 30min to dissolve to obtain a mixed solution. 40g of methyl vinyl silane and the mixed solution were added to the internal mixer, and the mixture was mixed at 160°C for 5min. After the mixing was completed, the mixture was transferred to a screw extruder for extrusion and granulation, and the head temperature was controlled at 140°C to obtain a flame retardant TPE composite material. Step 10: Extrude the flame-retardant TPE composite material onto the cable core through a sheath extruder to form an extremely fine line highly flame-retardant CAT6A signal transmission cable.

[0028] Based on Example 1, control experiments were conducted, specifically Comparative Example 1, Comparative Example 2 and Comparative Example 3, as described below: Comparative Example 1: This comparative example relates to a method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable. The difference from Example 1 is that high-density polyethylene is not grafted with propenyloxyacetophenone. Specifically: Step 1: Add 10g of hollow alumina balls to 100g of 5% hydrochloric acid, ultrasonically treat for 30 minutes, wash with deionized water, and dry. Add 2g of boron nitride to a mixture of 30g of 8% nitric acid and 30g of 10% hydrogen peroxide, ultrasonically treat for 60 minutes, wash with deionized water, and dry. Add the acid-treated hollow alumina balls to a dopamine-Tris buffer with a concentration of 2mg / mL, stir and react at 25°C and 200rpm for 2h, add the acid-treated boron nitride after 2h, continue stirring and reacting for 10h, filter after the reaction is completed, wash with deionized water, and dry at 60°C for 4h to obtain a composite thermally conductive insulating filler; Step 2: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust the pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermal conductive insulating filler, react at 80°C, 300rpm for 3h, filter after the reaction is complete, wash with ethanol and deionized water, and dry at 80°C for 2h to obtain a composite thermal conductive insulating filler; Step 3: 40g of high-density polyethylene, 0.4g of maleic anhydride, 0.12g of antioxidant 1010, and 0.72g of initiator benzophenone were placed in a torque rheometer and mixed at 140°C for 5 minutes. After 5 minutes, 0.4g of co-crosslinking agent tripropylene cyanurate and 5g of composite thermal conductive insulating filler were added and mixing was continued for 10 minutes. After mixing, vulcanization was performed on a flat vulcanizer at 140°C and 0.5MPa for 5 minutes. After vulcanization, the composite was irradiated under ultraviolet light with a wavelength of 365nm for 10 minutes to crosslink it and cooled to obtain an insulating HDPE composite material; Step 4: Extruding the insulating HDPE composite material onto the conductor through a core wire extruder to form an insulating core wire; Step 5: Twist the two independent insulated core wires together to form a pair of insulated core wires; Step 6: Twist four pairs of insulated core wires together, fill them with Kevlar fiber, and then wrap them with polytetrafluoroethylene tape to form the cable core; Step 7: Dry the low-density polyethylene at 80°C for 4 hours, dry the polyphenylene sulfide at 150°C for 3 hours, and dry the aluminum hydroxide and mica at 200°C for 2 hours. After drying, mix the aluminum hydroxide, mica and EVA wax in a mass ratio of 65:30:5, and extrude and granulate at 160°C to obtain a flame retardant masterbatch. Mix the maleic anhydride-grafted SEBS and low-density polyethylene in a mass ratio of 1:1, and extrude and granulate at 180°C to obtain a compatibilizer masterbatch. Step 8: After mixing 50g of polyethylene, 17g of polyphenylene sulfide, and 16g of compatibilizer masterbatch at 80°C and 300rpm for 5min, 35g of flame retardant masterbatch, 0.3g of antioxidant 1010, and 0.2g of antioxidant 168 were added, and the mixture was transferred to an internal mixer after continuing to mix for 10min. 0.8g of isopropyl peroxide and 0.5g of triallyl isocyanurate were added to 8g of methyl silicone oil, and the mixture was heated to 50°C and stirred continuously for 30min to dissolve to obtain a mixed solution. 30g of methyl vinyl silane and the mixed solution were added to the internal mixer, and the mixture was mixed at 160°C for 5min. After the mixing was completed, the mixture was transferred to a screw extruder for extrusion and granulation, and the head temperature was controlled at 140°C to obtain a flame retardant TPE composite material. Step 9: Extrude the flame-retardant TPE composite material onto the cable core through a sheath extruder to form an extremely fine line highly flame-retardant CAT6A signal transmission cable.

[0029] Comparative Example 2: This comparative example relates to a method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable. The difference from Example 1 is that no flame retardant is added to the TPE composite material during the preparation process. Specifically: Step 1: Mix 10 g of p-hydroxyacetophenone, 13.3 g of allyl bromide, and 120 g of acetone, stir until completely dissolved, add 40 g of anhydrous sodium carbonate, react for 12 hours and reflux, add 20 g of distilled water after 12 hours to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, and evaporate the excess solvent to obtain allyloxyacetophenone; Step 2: 10 g of hollow alumina spheres were added to 100 g of 5% hydrochloric acid, ultrasonically treated for 30 min, washed with deionized water, and dried. 2 g of boron nitride was added to a mixture of 30 g of 8% nitric acid and 30 g of 10% hydrogen peroxide, ultrasonically treated for 60 min, washed with deionized water, and dried. The acid-treated hollow alumina spheres were added to a dopamine-Tris buffer solution with a concentration of 2 mg / mL, stirred at 25 ° C and 200 rpm for 2 h, and then the acid-treated boron nitride was added after 2 h. The stirring reaction continued for 10 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried at 60 ° C for 4 h to obtain a composite thermally conductive insulating filler. Step 3: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust the pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermal conductive insulating filler, react at 80°C, 300rpm for 3h, filter after the reaction is completed, wash with ethanol and deionized water, and dry at 80°C for 2h to obtain a composite thermal conductive insulating filler; Step 4: 40g high-density polyethylene, 0.4g maleic anhydride, 0.12g antioxidant 1010, and 0.72g initiator benzophenone were placed in a torque rheometer and mixed at 140°C for 5 minutes. After 5 minutes, 0.4g of a cross-linking agent tripropylene cyanurate, 0.2g of propyleneoxyacetophenone, and 5g of a composite thermally conductive insulating filler were added and mixing continued for 10 minutes. After mixing, vulcanization was performed on a flat vulcanizer at 140°C and 0.5MPa for 5 minutes. After vulcanization, the composite was irradiated under ultraviolet light with a wavelength of 365nm for 10 minutes to crosslink it and cooled to obtain an insulating HDPE composite material; Step 5: Extruding the insulating HDPE composite material onto the conductor through a core wire extruder to form an insulating core wire; Step 6: Twist the two independent insulated core wires together to form a pair of insulated core wires; Step 7: Twist four pairs of insulated core wires together, fill them with Kevlar fiber, and then wrap them with polytetrafluoroethylene tape to form the cable core; Step 8: Dry the low-density polyethylene at 80°C for 4 hours, dry the polyphenylene sulfide at 150°C for 3 hours, and dry the aluminum hydroxide and mica at 200°C for 2 hours. After drying, mix the maleic anhydride-grafted SEBS and low-density polyethylene in a mass ratio of 1:1, and extrude and granulate at 180°C to obtain a compatibilizer masterbatch; Step 9: After mixing 50g of polyethylene, 17g of polyphenylene sulfide, and 16g of compatibilizer masterbatch at 80°C and 300rpm for 5min, 0.3g of antioxidant 1010 and 0.2g of antioxidant 168 were added, and the mixture was transferred to an internal mixer after continuing to mix for 10min. 0.8g of isopropyl peroxide and 0.5g of triallyl isocyanurate were added to 8g of methyl silicone oil, and the mixture was heated to 50°C and stirred continuously for 30min to dissolve to obtain a mixed solution. 30g of methyl vinyl silane and the mixed solution were added to the internal mixer, and the mixture was mixed at 160°C for 5min. After the mixing was completed, the mixture was transferred to a screw extruder for extrusion and granulation, and the head temperature was controlled at 140°C to obtain a flame retardant TPE composite material. Step 10: Extrude the flame-retardant TPE composite material onto the cable core through a sheath extruder to form an extremely fine line highly flame-retardant CAT6A signal transmission cable.

[0030] Comparative Example 3: This comparative example relates to a method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable. The difference from Example 1 is that no composite thermally conductive insulating filler is added. Specifically, Step 1: Mix 10 g of p-hydroxyacetophenone, 13.3 g of allyl bromide, and 120 g of acetone, stir until completely dissolved, add 40 g of anhydrous sodium carbonate, react for 12 hours and reflux, add 20 g of distilled water after 12 hours to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, and evaporate the excess solvent to obtain allyloxyacetophenone; Step 2: 40g of high-density polyethylene, 0.4g of maleic anhydride, 0.12g of antioxidant 1010, and 0.72g of initiator benzophenone were placed in a torque rheometer and mixed at 140°C for 5 minutes. After 5 minutes, 0.4g of co-crosslinking agent tripropylene cyanurate and 0.2g of propyleneoxyacetophenone were added and mixing was continued for 10 minutes. After mixing, vulcanization was performed on a flat vulcanizer at 140°C and 0.5MPa for 5 minutes. After vulcanization, the composite was irradiated under ultraviolet light with a wavelength of 365nm for 10 minutes to crosslink it, and cooled to obtain an insulating HDPE composite material; Step 3: Extruding the insulating HDPE composite material onto the conductor through a core wire extruder to form an insulating core wire; Step 4: Twist the two independent insulated core wires together to form a pair of insulated core wires; Step 5: Twist four pairs of insulated core wires together, fill them with Kevlar fiber, and then wrap them with polytetrafluoroethylene tape to form the cable core; Step 6: Dry the low-density polyethylene at 80°C for 4 hours, dry the polyphenylene sulfide at 150°C for 3 hours, and dry the aluminum hydroxide and mica at 200°C for 2 hours. After drying, mix the aluminum hydroxide, mica and EVA wax in a mass ratio of 65:30:5, and extrude and granulate at 160°C to obtain a flame retardant masterbatch. Mix the maleic anhydride-grafted SEBS and low-density polyethylene in a mass ratio of 1:1, and extrude and granulate at 180°C to obtain a compatibilizer masterbatch. Step 7: After mixing 50g of polyethylene, 17g of polyphenylene sulfide, and 16g of compatibilizer masterbatch at 80°C and 300rpm for 5min, 35g of flame retardant masterbatch, 0.3g of antioxidant 1010, and 0.2g of antioxidant 168 were added, and the mixture was transferred to an internal mixer after continuing to mix for 10min. 0.8g of isopropyl peroxide and 0.5g of triallyl isocyanurate were added to 8g of methyl silicone oil, and the mixture was heated to 50°C and stirred continuously for 30min to dissolve to obtain a mixed solution. 30g of methyl vinyl silane and the mixed solution were added to the internal mixer, and the mixture was mixed at 160°C for 5min. After the mixing was completed, the mixture was transferred to a screw extruder for extrusion and granulation, and the head temperature was controlled at 140°C to obtain a flame retardant TPE composite material. Step 8: Extrude the flame-retardant TPE composite material onto the cable core through a sheath extruder to form an extremely fine line highly flame-retardant CAT6A signal transmission cable.

[0031] Detection experiment: Ultra-fine line highly flame-retardant CAT6A signal transmission cable samples were prepared according to the preparation methods in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3, respectively.

[0032] Flame retardant performance test: The flame retardant performance of the cable is tested in accordance with the VW-1 test standard (Sec9.4) in the "Test Methods for Wires and Cables" (UL2556-2021). Three 24-inch (610mm) long specimens are cut from each ultra-fine high-flame retardant CAT6A signal transmission cable sample. The specimens are placed at room temperature (25°C) for 6 hours and straightened. After the treatment, the specimens are installed vertically in the test box, with the top of the specimen 6 inches (153mm) from the top of the box and the bottom of the specimen 12 inches (305mm) from the cotton layer. The flame of the Bunsen burner is adjusted to the standard height (125mm) and the inner flame height (40±2mm). The tip of the inner flame of the flame is aligned with the lower part of the specimen. The flame contacts the specimen for 15 seconds and then moves away for 15 seconds. A total of 5 contact combustions are performed, and the maximum value of the single afterflame burning time of the specimen, t, is recorded. max， Measure the height L of the char layer after the sample is burned to determine the VW-1 flame retardant grade standard of the sample. The VW-1 flame retardant grade standard is as follows: Afterflame time: After each flame is removed, the afterflame burning time of the sample is ≤ 60 seconds; Burnt area: The burnt / carbonized area of ​​the indicator flag is ≤ 25% (soot or erasable scorch marks are not included); Ignition of dripping materials: Burning dripping materials (particles or droplets) must not ignite the cotton wool at the bottom (carbonization of cotton wool without open flame is acceptable); Additional failure judgment (failure occurs if any of the following occurs): the self-ignition time after a single combustion is greater than 60 seconds; the dripping material ignites the cotton layer; the indicator flag is burned by more than 25%.

[0033] Insulation performance test: Dielectric performance test: The prepared cable sample is split in the middle, and after removing the conductor from the cable sample, it is pressed into a spline. A circular specimen with a diameter of 50 mm is taken from the spline. The test is carried out in accordance with the "Recommended method for measuring the permittivity and dielectric loss factor of electrical insulating materials at power frequency, audio frequency and high frequency (including meter wave wavelength)" (GB / T 1409-2006). First, the thickness of the specimen is measured with a thickness gauge, and then the specimen is placed in a dielectric constant tester to measure the dielectric constant (ε) and dielectric loss (tanδ) of the specimen.

[0034] Volume resistivity test: Split the prepared cable sample in the middle, take out the conductor from the cable sample, press it into a strip, take a 80mm×80mm square sample from the strip, and conduct the test according to the "Test method for determination of insulation resistance of solid insulating materials" (GB / T 10064-2006). First, measure the thickness of the sample with a thickness gauge, then put the sample into the volume resistivity tester, and measure the volume resistivity (ρ V ).

[0035] Conclusion: It can be seen from the test data that compared with Comparative Examples 1-3, the ultra-fine line high flame retardant CAT6A signal transmission cable sample prepared by the preparation method of Example 1 has a shorter self-extinguishing time, a smaller carbonization height, and better flame retardant performance. All samples in the experiment reached the VW-1 flame retardant grade. In addition, compared with Comparative Example 1, Comparative Example 2, and Comparative Example 3, the ultra-fine line high flame retardant CAT6A signal transmission cable sample prepared by the preparation method of Example 1 has a small dielectric constant and dielectric loss, a large volume resistivity, and good insulation performance. The ultra-fine line high flame retardant CAT6A signal transmission cable prepared by the present invention has good flame retardant and insulation properties, meeting the needs of the development of the network equipment connection industry.

[0036] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable, characterized by: Specifically: Step 1: Extruding the insulating HDPE composite material onto the conductor through a core wire extruder to form an insulating core wire; Step 2: Twist two independent insulated core wires together to form a pair of insulated core wires; Step 3: Twist four pairs of insulated core wires together, fill them with Kevlar fiber, and then wrap them with polytetrafluoroethylene tape to form a cable core; Step 4: Extrude the flame-retardant TPE composite material onto the cable core through a sheath extruder to form an extremely fine line highly flame-retardant CAT6A signal transmission cable.

2. The method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable according to claim 1, characterized in that: The preparation method of insulating HDPE composite material is as follows: Mix p-hydroxyacetophenone, allyl bromide, and acetone, stir until completely dissolved, add anhydrous sodium carbonate, react at room temperature for 10 to 14 hours and reflux, add distilled water after the reaction is complete to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, and evaporate the excess solvent to obtain allyloxyacetophenone; High-density polyethylene, maleic anhydride, antioxidant 1010, and benzophenone are uniformly mixed, and kneaded at 130-150° C. for 2-10 minutes. After 2-10 minutes, tripropylene cyanurate and propenyloxyacetophenone are added, and kneading is continued for 10-15 minutes. After the kneading is completed, vulcanization is carried out at 130-150° C. and 0.1-1.0 MPa for 5-10 minutes. After the vulcanization is completed, the material is irradiated under ultraviolet light with a wavelength of 365 nm for 5-15 minutes to be cross-linked, and the material is cooled to obtain an insulating HDPE composite material.

3. The method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable according to claim 2, characterized in that: Calculated by mass, the insulating HDPE composite material includes 35 to 45 parts of high-density polyethylene, 0.35 to 0.45 parts of maleic anhydride, 0.1 to 0.3 parts of antioxidant 1010, 0.5 to 1.0 parts of benzophenone, 0.2 to 0.5 parts of tripropylene cyanurate, 0.1 to 0.3 parts of propyleneoxyacetophenone, and 4.0 to 6.0 parts of composite thermally conductive insulating filler; the mass ratio of p-hydroxyacetophenone to allyl bromide is (9 to 11):(12 to 15).

4. The method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable according to claim 2, characterized in that: The preparation method of the composite thermal conductive insulating filler is as follows: Alumina hollow spheres are added to hydrochloric acid, ultrasonically treated for 20 to 30 minutes, washed with deionized water, and dried. Boron nitride is added to a mixture of nitric acid and hydrogen peroxide, ultrasonically treated for 40 to 60 minutes, washed with deionized water, and dried. The acid-treated alumina hollow spheres are added to dopamine-Tris buffer, stirred at 25 to 30° C. and 200 to 300 rpm for 1 to 2 hours, and acid-treated boron nitride is added after 1 to 2 hours, and the stirring reaction is continued for 8 to 10 hours. After the reaction is completed, the mixture is filtered, washed with deionized water, and dried at 60 to 70° C. for 3 to 4 hours to obtain a composite thermally conductive insulating filler.

5. The method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable according to claim 4, characterized in that: The mass fraction of hydrochloric acid is 3% to 8%, the mass ratio of hollow alumina spheres to hydrochloric acid is (1 to 2):(5 to 10); the mass fraction of nitric acid in the mixed solution is 3% to 8%, the mass fraction of hydrogen peroxide is 5% to 10%, and the mass ratio of boron nitride to the mixed solution is (1 to 2):(40 to 60); the concentration of dopamine in the dopamine-Tris buffer solution is 0.1 to 0.3 mg / mL; and the mass ratio of hollow alumina spheres, boron nitride, and dopamine-Tris buffer solution is (5 to 10):1:(90 to 110).

6. The method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable according to claim 1, characterized in that: The preparation method of the flame retardant TPE composite material is as follows: Polyethylene, polyphenylene sulfide, and compatibilizer masterbatch are mixed at 70-80°C and 200-300 rpm for 3-7 minutes, and then flame retardant masterbatch, antioxidant 1010, and antioxidant 168 are added. After continuing to mix for 10-15 minutes, the mixture is transferred to an internal mixer. Isopropyl benzene peroxide and triallyl isocyanurate are added to methyl silicone oil, and the mixture is heated to 50-60°C and stirred continuously for 20-30 minutes to dissolve to obtain a mixed solution. Methyl vinyl silane and the mixed solution are added to the internal mixer and mixed at 160-170°C for 3-7 minutes. After the mixing is completed, the mixture is transferred to a screw extruder for extrusion and granulation, and the head temperature is controlled at 140-150°C to obtain a flame-retardant TPE composite material.

7. The method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable according to claim 6, characterized in that: The flame retardant masterbatch is obtained by mixing aluminum hydroxide, mica and EVA wax and then extruding and granulating at 160°C; wherein the mass ratio of aluminum hydroxide, mica and EVA wax is (65-67):(25-28):(5-10).

8. The method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable according to claim 6, characterized in that: The compatibilizer masterbatch is obtained by mixing maleic anhydride grafted SEBS and low-density polyethylene and then extruding and granulating at 180° C. wherein the mass ratio of maleic anhydride grafted SEBS to low-density polyethylene is (0.7-1.5):

1.

9. The method for preparing an ultra-fine line highly flame-retardant CAT6A signal transmission cable according to claim 6, characterized in that: The flame-retardant TPE composite material includes, by mass, 50 to 60 parts of polyethylene, 17 to 22 parts of polyphenylene sulfide, 15 to 20 parts of compatibilizer masterbatch, 35 to 40 parts of flame retardant masterbatch, 0.3 to 0.5 parts of antioxidant 1010, 0.2 to 0.5 parts of antioxidant 168, 30 to 40 parts of methyl vinyl silane, 0.8 to 1.2 parts of isopropyl benzene peroxide and 0.5 to 1.0 parts of triallyl isocyanurate.

10. An ultra-fine line highly flame-retardant CAT6A signal transmission cable, characterized by: The cable conductor diameter is 34AWG and has signal integrity transmission performance through TIA Patch Cord Cat6A 15.0m.

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