A high flame-retardant CAT6A signal transmission cable with ultra-fine wires and its manufacturing method

Abstract

This invention relates to the field of cable sheathing technology, specifically disclosing an ultra-fine wire high flame-retardant CAT6A signal transmission cable and its preparation method. The invention involves wrapping an insulating HDPE composite material around a conductor to form an insulated core wire, then using Kevlar fiber as filler and covering it with polytetrafluoroethylene tape to form the cable core. Finally, a flame-retardant TPE composite material is wrapped around the cable core. The resulting cable exhibits excellent flame-retardant properties, self-extinguishing after being removed from the fire, and superior insulation performance, meeting the needs of the network equipment connection industry. It also possesses signal integrity transmission performance at 15.0m using TIA Patch Cord Cat6A.

Description

Technical Field

[0001] This invention relates to the field of cable sheath technology, specifically to an ultra-fine wire high flame-retardant CAT6A signal transmission cable and its preparation method. Background Technology

[0002] Cables are the carriers of signals. During signal transmission, the conductor—the cable core—plays a primary role. The cable sheath, protecting the cable core, is equally important. The sheath not only prevents corrosion and oxidation of the cable core, but polymer materials, due to their good mechanical properties, insulation performance, and light weight, also have unique advantages in cable sheath applications. However, in practical applications, the polymer materials used as cable sheaths are affected by environmental factors such as electric fields, temperature, and humidity, as well as mechanical stress. Combined with defects such as pores and impurities in the material, they are highly susceptible to partial discharge, leading to a decrease in insulation performance or even insulation breakdown, interfering with the normal transmission of data signals. Therefore, developing flame-retardant cables with good insulation performance is crucial for promoting the development of the network equipment connection industry. Summary of the Invention

[0003] The purpose of this invention is to provide an ultra-fine wire high flame retardant CAT6A signal transmission cable and its preparation method, thereby solving the problems of insufficient insulation and flame retardant performance of traditional signal transmission cables.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0005] A method for manufacturing an ultra-fine, high flame-retardant CAT6A signal transmission cable, specifically comprising:

[0006] Step 1: The insulating HDPE composite material is extruded and wrapped onto the conductor using a core wire extruder to form an insulated core wire;

[0007] Step 2: Twist the two independent insulated core wires together to form a pair of insulated core wires;

[0008] Step 3: Twist the four pairs of insulated core wires together, fill with Kevlar fiber, and then wrap with PTFE tape to form the cable core;

[0009] Step 4: The flame-retardant TPE composite material is extruded onto the cable core through a sheath extruder to form an ultra-fine, high flame-retardant CAT6A signal transmission cable.

[0010] As a limitation of the present invention, the preparation method of the insulating HDPE composite material is as follows:

[0011] p-Hydroxyacetophenone, bromopropene, and acetone were mixed and stirred until completely dissolved. Anhydrous sodium carbonate was added, and the mixture was reacted at room temperature for 10–14 h and then refluxed. After the reaction was completed, distilled water was added to dissolve the unreacted anhydrous sodium carbonate. The mixture was then extracted with dichloromethane, separated, and excess solvent was evaporated to obtain propenyloxyacetophenone.

[0012] High-density polyethylene, maleic anhydride, antioxidant 1010, and benzophenone are mixed evenly and kneaded at 130–150°C for 2–10 minutes. After 2–10 minutes, tripropylene cyanurate, propylene oxyacetophenone, and composite thermally conductive and insulating filler are added, and kneading continues for 10–15 minutes. After kneading, the mixture is vulcanized at 130–150°C and 0.1–1.0 MPa for 5–10 minutes. After vulcanization, the mixture is irradiated under ultraviolet light with a wavelength of 365 nm for 5–15 minutes to crosslink it. After cooling, an insulating HDPE composite material is obtained.

[0013] Under alkaline conditions, the phenolic hydroxyl group of p-hydroxyacetophenone undergoes a substitution reaction with the carbon-bromine bond of bromopropylene to generate propenyloxyacetophenone. The carbonyl group on propenyloxyacetophenone has high electron affinity, which can capture charge carriers and suppress space charge accumulation. The lone pair electrons on the propenyloxy group form weak hydrogen bonds with the carbon-hydrogen bonds of the HDPE chain, uniformly dispersing the trap energy levels. Under ultraviolet irradiation, the propenyl group initiates inter-chain crosslinking of HDPE to form a three-dimensional network structure, which improves the resistance to electrical dendration.

[0014] As a limitation of the present invention, the insulating HDPE composite material comprises, by weight, 35-45 parts high-density polyethylene, 0.35-0.45 parts maleic anhydride, 0.1-0.3 parts antioxidant 1010, 0.5-1.0 parts benzophenone, 0.2-0.5 parts tripropylene cyanurate, 0.1-0.3 parts propylene oxyacetophenone, and 4.0-6.0 parts composite thermally conductive and insulating filler; the mass ratio of p-hydroxyacetophenone to propylene bromide is (9-11):(12-15).

[0015] As a limitation of this invention, the preparation method of the composite thermally conductive and insulating filler is as follows:

[0016] Hollow alumina spheres were added to hydrochloric acid and sonicated for 20–30 min, then washed with deionized water and dried. Boron nitride was added to a mixture of nitric acid and hydrogen peroxide and sonicated for 40–60 min, then washed with deionized water and dried. The acid-treated hollow alumina spheres were added to dopamine-Tris buffer solution and stirred at 25–30 °C and 200–300 rpm for 1–2 h. After 1–2 h, acid-treated boron nitride was added, and the reaction was continued for 8–10 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried at 60–70 °C for 3–4 h to obtain a composite thermally conductive and insulating filler.

[0017] Using dopamine and boron nitride as raw materials, a polydopamine coating layer doped with boron nitride is generated on the surface of hollow alumina spheres. The hollow alumina spheres can reduce the material density while improving the material's toughness and high-temperature resistance. The polydopamine shell ensures the dispersion and adhesion of the filler in the high-density polyethylene matrix. Boron nitride forms a thermally conductive network in the polydopamine shell, ensuring that the material's insulation does not deteriorate while improving the material's thermal conductivity.

[0018] As a limitation of the present invention, the hydrochloric acid has a mass fraction of 3% to 8%, and the mass ratio of alumina hollow spheres to hydrochloric acid is (1 to 2):(5 to 10); the mass fraction of nitric acid in the mixture is 3% to 8%, the mass fraction of hydrogen peroxide is 5% to 10%, and the mass ratio of boron nitride to the mixture 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 alumina hollow spheres, boron nitride, and dopamine-Tris buffer is (5 to 10):1:(90 to 110).

[0019] As a limitation of this invention, the preparation method of the flame-retardant TPE composite material is as follows:

[0020] Polyethylene, polyphenylene sulfide, and compatibilizer masterbatch are mixed at 70-80℃ and 200-300rpm for 3-7 minutes. Then, flame retardant masterbatch, antioxidant 1010, and antioxidant 168 are added, and the mixture is continued for 10-15 minutes. The mixture is then transferred to an internal mixer. Cumene peroxide and triallyl isocyanurate are added to methyl silicone oil, heated to 50-60℃, and stirred continuously for 20-30 minutes to dissolve the mixture. Methyl vinyl silane and the mixture are then added to the internal mixer and kneaded at 160-170℃ for 3-7 minutes. After kneading, the mixture is transferred to a screw extruder for extrusion and granulation. The die head temperature is controlled at 140-150℃ to obtain the flame-retardant TPE composite material.

[0021] Polyethylene is used as the plastic phase, and silicone rubber with good weather resistance and insulation is used as the elastic phase as the matrix of thermoplastic elastomer (TPE). Polyphenylene sulfide is added as a heat-resistant structure to improve the long-term temperature resistance of TPE. Cumene peroxide is the main crosslinking agent and triallyl isocyanurate is the auxiliary crosslinking agent, which helps the silicone rubber in the matrix to crosslink and form a heat-resistant network, thereby improving the temperature resistance and mechanical properties of the composite material. Antioxidant 1010 and antioxidant 168 work synergistically to enhance the weather resistance of the composite material.

[0022] 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).

[0023] The flame-retardant TPE composite material made of aluminum hydroxide and mica exhibits the following characteristics during combustion: aluminum hydroxide decomposes and absorbs heat, releasing water vapor and aluminum oxide. The water vapor captures free radicals generated during combustion; mica sheets block the diffusion of heat and combustible gases; at high temperatures, mica reacts with aluminum oxide to form a dense, high-temperature resistant ceramic layer, which isolates oxygen and combustible gases while maintaining structural integrity and reducing molten dripping. In addition, the silicone rubber in the material burns to generate silicon oxide, which participates in the mica ceramicization reaction and enhances the strength of the combustion residue.

[0024] 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.

[0025] Maleic anhydride grafted with SEBS acts as a compatibilizer. One end of the SEBS chain is compatible with PE, while the other end of the maleic anhydride can combine with the end groups of polyphenylene sulfide, the silanol groups of silicone rubber, and inorganic fillers (flame retardants), reducing the interfacial tension between PE and silicone rubber and improving the dispersibility of polyphenylene sulfide, silicone rubber, and inorganic fillers in TPE materials.

[0026] As a limitation of the present invention, the flame-retardant TPE composite material comprises, by weight, 50-60 parts polyethylene, 17-22 parts polyphenylene sulfide, 15-20 parts compatibilizer masterbatch, 35-40 parts flame retardant masterbatch, 0.3-0.5 parts antioxidant 1010, 0.2-0.5 parts antioxidant 168, 30-40 parts methyl vinyl silane, 0.8-1.2 parts cumene peroxide, and 0.5-1.0 parts triallyl isocyanurate.

[0027] A high flame-retardant CAT6A signal transmission cable with ultra-fine wires and a conductor diameter of 34AWG has signal integrity transmission performance through TIAPatch Cord Cat6A 15.0m.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] To modify high-density polyethylene (HDPE), propenyloxyacetophenone (POA) and maleic anhydride were grafted onto the polyethylene molecular chain. By introducing a double bond group at the para position of POA to form propenyloxyacetophenone, and then grafting it onto HDPE, the propenyloxyacetophenone can absorb high-energy electrons through the interconversion between its keto and enol forms, releasing the energy harmlessly as light and heat, thus protecting the polyethylene macromolecular chain. The grafted polar compound, maleic anhydride, can introduce densely distributed deep traps into the polymer structure. These deep traps capture injected charges, forming a barrier that inhibits further charge injection, thereby suppressing space charge.

[0030] Using dopamine and boron nitride as raw materials, a polydopamine coating layer doped with boron nitride is generated on the surface of hollow alumina spheres. The hollow alumina spheres can reduce the material density while improving the material's toughness and high-temperature resistance. The polydopamine shell ensures the dispersion and adhesion of the filler in the high-density polyethylene matrix. Boron nitride forms a thermally conductive network in the polydopamine shell, ensuring that the material's insulation does not deteriorate while improving the material's thermal conductivity.

[0031] Polyethylene is used as the plastic phase, and silicone rubber with good weather resistance and insulation is used as the elastic phase as the matrix of thermoplastic elastomer (TPE). Polyphenylene sulfide is added as a heat-resistant structure to improve the long-term temperature resistance of TPE. A flame retardant composed of aluminum hydroxide and mica is added to retard the flame, and antioxidants 1010 and 168 are added to improve the weather resistance of the composite material. Attached Figure Description

[0032] Figure 1 A cross-sectional view of the finished product of the ultra-fine wire high flame retardant CAT6A signal transmission cable prepared by the preparation method in Example 1 is shown. The conductor in the cable is 34AWG bare stranded copper. The flame retardant TPE sheath layer of the cable is formed by extrusion of flame retardant TPE composite material through a sheath extruder. The HDPE insulation layer of the cable is formed by extrusion of insulating HDPE composite material through a core wire extruder. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Conductor (34AWG bare stranded copper, 19 strands, 0.04±0.003mm), Kevlar fiber (1500D), PTFE tape (7×0.05mm), high-density polyethylene (041-T, 0.96g / cm³). 3 Alumina hollow spheres (particle size: 10 μm, wall thickness 500 nm), dopamine-Tris buffer (pH=8.5, dopamine concentration 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 (sheet 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).

[0035] Example 1: A method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable, specifically as follows:

[0036] Step 1: Mix 10g of p-hydroxyacetophenone, 13.3g of bromopropene and 120g of acetone, stir until completely dissolved, add 40g of anhydrous sodium carbonate, react for 12h and reflux, after 12h add 20g of distilled water to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, evaporate excess solvent to obtain propenyloxyacetophenone;

[0037] Step 2: Add 10g of hollow alumina spheres to 100g of 5% hydrochloric acid, sonicate for 30min, 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, sonicate for 60min, wash with deionized water, and dry. Add the acid-treated hollow alumina spheres to a 2mg / mL dopamine-Tris buffer solution, stir at 25℃ and 200rpm for 2h, add the acid-treated boron nitride, and continue stirring for 10h. After the reaction is complete, filter, wash with deionized water, and dry at 60℃ for 4h to obtain the composite thermally conductive and insulating filler.

[0038] Step 3: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermally conductive and insulating filler, react at 80℃ and 300rpm for 3h, filter after reaction, wash with ethanol and deionized water, dry at 80℃ for 2h to obtain composite thermally conductive and insulating filler;

[0039] Step 4: Place 40g of high-density polyethylene, 0.4g of maleic anhydride, 0.12g of antioxidant 1010, and 0.72g of initiator benzophenone into a torque rheometer and mix at 140℃ for 5 minutes. After 5 minutes, add 0.4g of crosslinking agent tripropylene cyanurate, 0.2g of propylene oxyacetophenone, and 5g of composite thermally conductive and insulating filler, and continue mixing for 10 minutes. After mixing, vulcanize at 140℃ and 0.5MPa for 5 minutes using a flat vulcanizing machine. After vulcanization, irradiate with ultraviolet light at a wavelength of 365nm for 10 minutes to crosslink the material. Cool to obtain an insulating HDPE composite material.

[0040] Step 5: The insulating HDPE composite material is extruded and wrapped onto the conductor using a core wire extruder to form an insulated core wire;

[0041] Step 6: Twist the two independent insulated core wires together to form a pair of insulated core wires;

[0042] Step 7: Twist the four pairs of insulated core wires together, fill with Kevlar fiber, and then wrap with PTFE tape to form the cable core;

[0043] Step 8: Dry low-density polyethylene at 80℃ for 4 hours, polyphenylene sulfide at 150℃ for 3 hours, and aluminum hydroxide and mica at 200℃ for 2 hours. After drying, mix aluminum hydroxide, mica and EVA wax at a mass ratio of 65:30:5 and granulate at 160℃ to obtain flame retardant masterbatch. Mix maleic anhydride grafted SEBS and low-density polyethylene at a mass ratio of 1:1 and granulate at 180℃ to obtain compatibilizer masterbatch.

[0044] Step 9: Mix 50g polyethylene, 17g polyphenylene sulfide, and 16g compatibilizer masterbatch at 80℃ and 300rpm for 5min. Then add 35g flame retardant masterbatch, 0.3g antioxidant 1010, and 0.2g antioxidant 168. Continue mixing for 10min and then transfer to a mixer. Add 0.8g cumene peroxide and 0.5g triallyl isocyanurate to 8g methyl silicone oil. Heat to 50℃ and stir continuously for 30min to dissolve and obtain a mixture. Add 30g methyl vinyl silane and the mixture to the mixer and mix at 160℃ for 5min. After mixing, transfer to a screw extruder for extrusion and granulation. Control the die head temperature at 140℃ to obtain a flame-retardant TPE composite material.

[0045] Step 10: The flame-retardant TPE composite material is extruded onto the cable core through a sheath extruder to form an ultra-fine, high flame-retardant CAT6A signal transmission cable.

[0046] Example 2: A method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable, specifically as follows:

[0047] Step 1: Mix 10g of p-hydroxyacetophenone, 13.3g of bromopropene and 120g of acetone, stir until completely dissolved, add 40g of anhydrous sodium carbonate, react for 12h and reflux, after 12h add 20g of distilled water to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, evaporate excess solvent to obtain propenyloxyacetophenone;

[0048] Step 2: Add 10g of hollow alumina spheres to 100g of 5% hydrochloric acid, sonicate for 30min, 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, sonicate for 60min, wash with deionized water, and dry. Add the acid-treated hollow alumina spheres to a 2mg / mL dopamine-Tris buffer solution, stir at 25℃ and 200rpm for 2h, add the acid-treated boron nitride, and continue stirring for 10h. After the reaction is complete, filter, wash with deionized water, and dry at 60℃ for 4h to obtain the composite thermally conductive and insulating filler.

[0049] Step 3: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermally conductive and insulating filler, react at 80℃ and 300rpm for 3h, filter after reaction, wash with ethanol and deionized water, dry at 80℃ for 2h to obtain composite thermally conductive and insulating filler;

[0050] Step 4: Place 42g of high-density polyethylene, 0.42g of maleic anhydride, 0.2g of antioxidant 1010, and 0.8g of initiator benzophenone into a torque rheometer and mix at 140℃ for 5 minutes. After 5 minutes, add 0.4g of crosslinking agent tripropylene cyanurate, 0.2g of propylene oxyacetophenone, and 5.5g of composite thermally conductive and insulating filler, and continue mixing for 10 minutes. After mixing, vulcanize at 140℃ and 0.5MPa for 5 minutes using a flat vulcanizing machine. After vulcanization, irradiate with ultraviolet light at a wavelength of 365nm for 10 minutes to crosslink the material. Cool to obtain an insulating HDPE composite material.

[0051] Step 5: The insulating HDPE composite material is extruded and wrapped onto the conductor using a core wire extruder to form an insulated core wire;

[0052] Step 6: Twist the two independent insulated core wires together to form a pair of insulated core wires;

[0053] Step 7: Twist the four pairs of insulated core wires together, fill with Kevlar fiber, and then wrap with PTFE tape to form the cable core;

[0054] Step 8: Dry low-density polyethylene at 80℃ for 4 hours, polyphenylene sulfide at 150℃ for 3 hours, and aluminum hydroxide and mica at 200℃ for 2 hours. After drying, mix aluminum hydroxide, mica and EVA wax at a mass ratio of 65:30:5 and granulate at 160℃ to obtain flame retardant masterbatch. Mix maleic anhydride grafted SEBS and low-density polyethylene at a mass ratio of 1:1 and granulate at 180℃ to obtain compatibilizer masterbatch.

[0055] Step 9: Mix 55g polyethylene, 19g polyphenylene sulfide, and 18g compatibilizer masterbatch at 80℃ and 300rpm for 5min. Then add 37g flame retardant masterbatch, 0.3g antioxidant 1010, and 0.2g antioxidant 168. Continue mixing for 10min and then transfer to a mixer. Add 0.8g cumene peroxide and 0.5g triallyl isocyanurate to 8g methyl silicone oil. Heat to 50℃ and stir continuously for 30min to dissolve and obtain a mixture. Add 35g methyl vinyl silane and the mixture to the mixer and mix at 160℃ for 5min. After mixing, transfer to a screw extruder for extrusion and granulation. Control the die head temperature at 140℃ to obtain a flame-retardant TPE composite material.

[0056] Step 10: The flame-retardant TPE composite material is extruded onto the cable core through a sheath extruder to form an ultra-fine, high flame-retardant CAT6A signal transmission cable.

[0057] Example 3: A method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable, specifically as follows:

[0058] Step 1: Mix 10g of p-hydroxyacetophenone, 13.3g of bromopropene and 120g of acetone, stir until completely dissolved, add 40g of anhydrous sodium carbonate, react for 12h and reflux, after 12h add 20g of distilled water to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, evaporate excess solvent to obtain propenyloxyacetophenone;

[0059] Step 2: Add 10g of hollow alumina spheres to 100g of 5% hydrochloric acid, sonicate for 30min, 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, sonicate for 60min, wash with deionized water, and dry. Add the acid-treated hollow alumina spheres to a 2mg / mL dopamine-Tris buffer solution, stir at 25℃ and 200rpm for 2h, add the acid-treated boron nitride, and continue stirring for 10h. After the reaction is complete, filter, wash with deionized water, and dry at 60℃ for 4h to obtain the composite thermally conductive and insulating filler.

[0060] Step 3: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermally conductive and insulating filler, react at 80℃ and 300rpm for 3h, filter after reaction, wash with ethanol and deionized water, dry at 80℃ for 2h to obtain composite thermally conductive and insulating filler;

[0061] Step 4: Place 45g of high-density polyethylene, 0.45g of maleic anhydride, 0.25g of antioxidant 1010, and 0.9g of initiator benzophenone into a torque rheometer and mix at 140℃ for 5 minutes. After 5 minutes, add 0.4g of crosslinking agent tripropylene cyanurate, 0.2g of propylene oxyacetophenone, and 6g of composite thermally conductive and insulating filler, and continue mixing for 10 minutes. After mixing, vulcanize at 140℃ and 0.5MPa for 5 minutes using a flat vulcanizing machine. After vulcanization, irradiate with ultraviolet light at a wavelength of 365nm for 10 minutes to crosslink the material. Cool to obtain an insulating HDPE composite material.

[0062] Step 5: The insulating HDPE composite material is extruded and wrapped onto the conductor using a core wire extruder to form an insulated core wire;

[0063] Step 6: Twist the two independent insulated core wires together to form a pair of insulated core wires;

[0064] Step 7: Twist the four pairs of insulated core wires together, fill with Kevlar fiber, and then wrap with PTFE tape to form the cable core;

[0065] Step 8: Dry low-density polyethylene at 80℃ for 4 hours, polyphenylene sulfide at 150℃ for 3 hours, and aluminum hydroxide and mica at 200℃ for 2 hours. After drying, mix aluminum hydroxide, mica and EVA wax at a mass ratio of 65:30:5 and granulate at 160℃ to obtain flame retardant masterbatch. Mix maleic anhydride grafted SEBS and low-density polyethylene at a mass ratio of 1:1 and granulate at 180℃ to obtain compatibilizer masterbatch.

[0066] Step 9: Mix 60g polyethylene, 22g polyphenylene sulfide, and 20g compatibilizer masterbatch at 80℃ and 300rpm for 5min. Then add 40g flame retardant masterbatch, 0.3g antioxidant 1010, and 0.2g antioxidant 168. Continue mixing for 10min and then transfer to a mixer. Add 0.8g cumene peroxide and 0.5g triallyl isocyanurate to 8g methyl silicone oil. Heat to 50℃ and stir continuously for 30min to dissolve and obtain a mixture. Add 40g methyl vinyl silane and the mixture to the mixer and mix at 160℃ for 5min. After mixing, transfer to a screw extruder for extrusion and granulation. Control the die head temperature at 140℃ to obtain a flame-retardant TPE composite material.

[0067] Step 10: The flame-retardant TPE composite material is extruded onto the cable core through a sheath extruder to form an ultra-fine, high flame-retardant CAT6A signal transmission cable.

[0068] Based on Example 1, the following comparative experiments were conducted, specifically Comparative Example 1, Comparative Example 2, and Comparative Example 3, as described below:

[0069] Comparative Example 1: This comparative example relates to a method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable. The difference from Example 1 is that it does not use propylene-based oxyacetophenone grafted onto high-density polyethylene. Specifically:

[0070] Step 1: Add 10g of hollow alumina spheres to 100g of 5% hydrochloric acid, sonicate for 30min, 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, sonicate for 60min, wash with deionized water, and dry. Add the acid-treated hollow alumina spheres to a 2mg / mL dopamine-Tris buffer solution, stir at 25℃ and 200rpm for 2h, add the acid-treated boron nitride, and continue stirring for 10h. After the reaction is complete, filter, wash with deionized water, and dry at 60℃ for 4h to obtain the composite thermally conductive and insulating filler.

[0071] Step 2: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermally conductive and insulating filler, react at 80℃ and 300rpm for 3h, filter after reaction, wash with ethanol and deionized water, dry at 80℃ for 2h to obtain composite thermally conductive and insulating filler;

[0072] Step 3: Place 40g of high-density polyethylene, 0.4g of maleic anhydride, 0.12g of antioxidant 1010, and 0.72g of initiator benzophenone into a torque rheometer and mix at 140℃ for 5 minutes. After 5 minutes, add 0.4g of crosslinking agent tripropylene cyanurate and 5g of composite thermally conductive and insulating filler, and continue mixing for 10 minutes. After mixing, vulcanize at 140℃ and 0.5MPa for 5 minutes using a flat vulcanizing machine. After vulcanization, irradiate with ultraviolet light at a wavelength of 365nm for 10 minutes to crosslink the material. Cool to obtain an insulating HDPE composite material.

[0073] Step 4: The insulating HDPE composite material is extruded and wrapped onto the conductor using a core wire extruder to form an insulated core wire;

[0074] Step 5: Twist the two independent insulated core wires together to form a pair of insulated core wires;

[0075] Step 6: Twist the four pairs of insulated core wires together, fill with Kevlar fiber, and then wrap with PTFE tape to form the cable core;

[0076] Step 7: Dry low-density polyethylene at 80℃ for 4 hours, polyphenylene sulfide at 150℃ for 3 hours, and aluminum hydroxide and mica at 200℃ 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℃ to obtain 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℃ to obtain compatibilizer masterbatch.

[0077] Step 8: Mix 50g polyethylene, 17g polyphenylene sulfide, and 16g compatibilizer masterbatch at 80℃ and 300rpm for 5min. Then add 35g flame retardant masterbatch, 0.3g antioxidant 1010, and 0.2g antioxidant 168. Continue mixing for 10min and then transfer to a mixer. Add 0.8g cumene peroxide and 0.5g triallyl isocyanurate to 8g methyl silicone oil. Heat to 50℃ and stir continuously for 30min to dissolve and obtain a mixture. Add 30g methyl vinyl silane and the mixture to the mixer and mix at 160℃ for 5min. After mixing, transfer to a screw extruder for extrusion and granulation. Control the die head temperature at 140℃ to obtain a flame-retardant TPE composite material.

[0078] Step 9: The flame-retardant TPE composite material is extruded onto the cable core through a sheath extruder to form an ultra-fine, high flame-retardant CAT6A signal transmission cable.

[0079] Comparative Example 2: This comparative example relates to a method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable. The difference from Example 1 is that no flame retardant was added to the TPE composite material during the preparation process. Specifically:

[0080] Step 1: Mix 10g of p-hydroxyacetophenone, 13.3g of bromopropene and 120g of acetone, stir until completely dissolved, add 40g of anhydrous sodium carbonate, react for 12h and reflux, after 12h add 20g of distilled water to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, evaporate excess solvent to obtain propenyloxyacetophenone;

[0081] Step 2: Add 10g of hollow alumina spheres to 100g of 5% hydrochloric acid, sonicate for 30min, 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, sonicate for 60min, wash with deionized water, and dry. Add the acid-treated hollow alumina spheres to a 2mg / mL dopamine-Tris buffer solution, stir at 25℃ and 200rpm for 2h, add the acid-treated boron nitride, and continue stirring for 10h. After the reaction is complete, filter, wash with deionized water, and dry at 60℃ for 4h to obtain the composite thermally conductive and insulating filler.

[0082] Step 3: Mix 0.3g KH-560 silane coupling agent with 99.7g ethanol, stir evenly, adjust pH to 5, hydrolyze at room temperature for 30min, add 10g composite thermally conductive and insulating filler, react at 80℃ and 300rpm for 3h, filter after reaction, wash with ethanol and deionized water, dry at 80℃ for 2h to obtain composite thermally conductive and insulating filler;

[0083] Step 4: Place 40g of high-density polyethylene, 0.4g of maleic anhydride, 0.12g of antioxidant 1010, and 0.72g of initiator benzophenone into a torque rheometer and mix at 140℃ for 5 minutes. After 5 minutes, add 0.4g of crosslinking agent tripropylene cyanurate, 0.2g of propylene oxyacetophenone, and 5g of composite thermally conductive and insulating filler, and continue mixing for 10 minutes. After mixing, vulcanize at 140℃ and 0.5MPa for 5 minutes using a flat vulcanizing machine. After vulcanization, irradiate with ultraviolet light at a wavelength of 365nm for 10 minutes to crosslink the material. Cool to obtain an insulating HDPE composite material.

[0084] Step 5: The insulating HDPE composite material is extruded and wrapped onto the conductor using a core wire extruder to form an insulated core wire;

[0085] Step 6: Twist the two independent insulated core wires together to form a pair of insulated core wires;

[0086] Step 7: Twist the four pairs of insulated core wires together, fill with Kevlar fiber, and then wrap with PTFE tape to form the cable core;

[0087] Step 8: Dry low-density polyethylene at 80℃ for 4 hours, polyphenylene sulfide at 150℃ for 3 hours, and aluminum hydroxide and mica at 200℃ for 2 hours. After drying, mix maleic anhydride-grafted SEBS and low-density polyethylene at a mass ratio of 1:1, and then extrude and granulate at 180℃ to obtain compatibilizer masterbatch.

[0088] Step 9: Mix 50g polyethylene, 17g polyphenylene sulfide, and 16g compatibilizer masterbatch at 80℃ and 300rpm for 5min. Then add 0.3g antioxidant 1010 and 0.2g antioxidant 168, and continue mixing for 10min. Transfer the mixture to a mixer. Add 0.8g cumene peroxide and 0.5g triallyl isocyanurate to 8g methyl silicone oil. Heat to 50℃ and stir continuously for 30min to dissolve and obtain a mixture. Add 30g methyl vinyl silane and the mixture to the mixer and mix at 160℃ for 5min. After mixing, transfer the mixture to a screw extruder for extrusion and granulation. Control the die head temperature at 140℃ to obtain a flame-retardant TPE composite material.

[0089] Step 10: The flame-retardant TPE composite material is extruded onto the cable core through a sheath extruder to form an ultra-fine, high flame-retardant CAT6A signal transmission cable.

[0090] Comparative Example 3: This comparative example relates to a method for preparing an ultra-fine wire high flame-retardant CAT6A signal transmission cable. The difference from Example 1 is that no composite thermally conductive insulating filler is added. Specifically:

[0091] Step 1: Mix 10g of p-hydroxyacetophenone, 13.3g of bromopropene and 120g of acetone, stir until completely dissolved, add 40g of anhydrous sodium carbonate, react for 12h and reflux, after 12h add 20g of distilled water to dissolve the unreacted anhydrous sodium carbonate, extract with dichloromethane, separate, evaporate excess solvent to obtain propenyloxyacetophenone;

[0092] Step 2: Place 40g of high-density polyethylene, 0.4g of maleic anhydride, 0.12g of antioxidant 1010, and 0.72g of initiator benzophenone into a torque rheometer and mix at 140℃ for 5 minutes. After 5 minutes, add 0.4g of crosslinking agent tripropylene cyanurate and 0.2g of propylene oxyacetophenone and continue mixing for 10 minutes. After mixing, vulcanize at 140℃ and 0.5MPa for 5 minutes using a flat vulcanizing machine. After vulcanization, irradiate with ultraviolet light at a wavelength of 365nm for 10 minutes to crosslink the material. Cool to obtain an insulating HDPE composite material.

[0093] Step 3: The insulating HDPE composite material is extruded and wrapped onto the conductor using a core wire extruder to form an insulated core wire;

[0094] Step 4: Twist the two independent insulated core wires together to form a pair of insulated core wires;

[0095] Step 5: Twist the four pairs of insulated core wires together, fill with Kevlar fiber, and then wrap with PTFE tape to form the cable core;

[0096] Step 6: Dry low-density polyethylene at 80℃ for 4 hours, polyphenylene sulfide at 150℃ for 3 hours, and aluminum hydroxide and mica at 200℃ for 2 hours. After drying, mix aluminum hydroxide, mica and EVA wax at a mass ratio of 65:30:5 and granulate at 160℃ to obtain flame retardant masterbatch. Mix maleic anhydride grafted SEBS and low-density polyethylene at a mass ratio of 1:1 and granulate at 180℃ to obtain compatibilizer masterbatch.

[0097] Step 7: Mix 50g polyethylene, 17g polyphenylene sulfide, and 16g compatibilizer masterbatch at 80℃ and 300rpm for 5min. Then add 35g flame retardant masterbatch, 0.3g antioxidant 1010, and 0.2g antioxidant 168. Continue mixing for 10min and then transfer to a mixer. Add 0.8g cumene peroxide and 0.5g triallyl isocyanurate to 8g methyl silicone oil. Heat to 50℃ and stir continuously for 30min to dissolve and obtain a mixture. Add 30g methyl vinyl silane and the mixture to the mixer and mix at 160℃ for 5min. After mixing, transfer to a screw extruder for extrusion and granulation. Control the die head temperature at 140℃ to obtain a flame-retardant TPE composite material.

[0098] Step 8: The flame-retardant TPE composite material is extruded onto the cable core through a sheath extruder to form an ultra-fine, high flame-retardant CAT6A signal transmission cable.

[0099] Testing experiment:

[0100] Extremely fine, high flame-retardant CAT6A signal transmission cable samples were prepared according to the preparation methods in Examples 1, 2, 3, Comparative Examples 1, 2, and 3, respectively.

[0101] Flame retardant performance test: The flame retardant performance of the cable was tested according to the VW-1 test standard (Sec9.4) in "Test Methods for Wires and Cables" (UL2556-2021). Three 24-inch (610 mm) long samples were cut from each of the ultra-fine high flame retardant CAT6A signal transmission cable samples. The samples were placed at room temperature (25℃) for 6 hours and straightened. After the straightening treatment, the samples were vertically installed in the test chamber, with the top of the sample 6 inches (153 mm) from the top of the chamber and the bottom of the sample 12 inches (305 mm) from the cotton layer. The Bunsen burner flame was adjusted to the standard height (125 mm) and the inner flame height (40 ± 2 mm). The tip of the inner flame was aligned with the lower part of the sample, and the flame was in contact with the sample for 15 seconds and removed for 15 seconds. A total of 5 contact combustions were carried out, and the maximum value of the afterflame burning time of the sample in a single contact was recorded. max， The height L of the char layer after combustion is measured to determine the VW-1 flame retardant rating of the sample. The VW-1 flame retardant rating standard is as follows:

[0102] Afterflame time: The afterflame burning time of the sample is ≤60 seconds after each flame is removed;

[0103] Burn damage range: charred / carbonized area of ​​the indicator flag ≤25% (smoke ash or removable scorch marks are not included);

[0104] Ignition properties of dripping material: Burning dripping material (particles or droplets) must not ignite the cotton wadding at the bottom (carbonization of the cotton wadding without open flame is acceptable);

[0105] Additional failure criteria (failure occurs if any of these occur): Spontaneous combustion time after a single burn > 60 seconds; dripping material ignites the cotton layer; indicator flag burns > 25%.

[0106] Insulation performance test:

[0107] Dielectric performance testing: The prepared cable sample is cut open from the middle, the conductor inside the cable sample is removed, and it is pressed into a strip. A circular sample with a diameter of 50 mm is taken from the strip. The test is carried out according to 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 sample is measured with a thickness gauge, and then the sample is placed in a dielectric constant tester to measure the dielectric constant (ε) and dielectric loss (tanδ) of the sample.

[0108] Volume resistivity test: The prepared cable sample is cut in half lengthwise, the conductor is removed, and the sample is pressed into a strip. An 80mm × 80mm square specimen is taken from the strip. The test is conducted according to the "Test Method for Determination of Insulation Resistance of Solid Insulating Materials" (GB / T 10064-2006). First, the thickness of the specimen is measured using a thickness gauge. Then, the specimen is placed in a volume resistivity tester to measure the volume resistivity (ρ). V ).

[0109]

[0110] Conclusion: The experimental data shows that, compared with Comparative Examples 1-3, the ultra-fine wire high flame-retardant CAT6A signal transmission cable samples prepared by the method of Example 1 have shorter self-extinguishing time, lower carbonization height, and better flame-retardant performance. All samples achieved the VW-1 flame-retardant rating in the experiment. Furthermore, compared with Comparative Examples 1, 2, and 3, the ultra-fine wire high flame-retardant CAT6A signal transmission cable samples prepared by the method of Example 1 have lower dielectric constant and dielectric loss, higher volume resistivity, and better insulation performance. The ultra-fine wire high flame-retardant CAT6A signal transmission cable prepared by this invention has good flame-retardant and insulation properties, meeting the needs of the network equipment connection industry.

[0111] 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 implemented 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 exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable, characterized in that: Specifically: Step 1: The insulating HDPE composite material is extruded and wrapped onto the conductor using a core wire extruder to form an insulated core wire; Step 2: Twist the two independent insulated core wires together to form a pair of insulated core wires; Step 3: Twist the four pairs of insulated core wires together, fill with Kevlar fiber, and then wrap with PTFE tape to form the cable core; Step 4: The flame-retardant TPE composite material is extruded onto the cable core through a sheath extruder to form an ultra-fine, high flame-retardant CAT6A signal transmission cable. The preparation method of the insulating HDPE composite material is as follows: p-Hydroxyacetophenone, bromopropene, and acetone were mixed and stirred until completely dissolved. Anhydrous sodium carbonate was added, and the mixture was reacted at room temperature for 10–14 h and then refluxed. After the reaction was completed, distilled water was added to dissolve the unreacted anhydrous sodium carbonate. The mixture was then extracted with dichloromethane, separated, and excess solvent was evaporated to obtain propenyloxyacetophenone. High-density polyethylene, maleic anhydride, antioxidant 1010, and benzophenone are mixed evenly and kneaded at 130-150℃ for 2-10 minutes. After 2-10 minutes, tripropylene cyanurate, propylene oxyacetophenone, and composite thermally conductive and insulating filler are added, and kneading is continued for 10-15 minutes. After kneading, the mixture is vulcanized at 130-150℃ and 0.1-1.0MPa for 5-10 minutes. After vulcanization, the mixture is irradiated under ultraviolet light with a wavelength of 365nm for 5-15 minutes to crosslink it. After cooling, an insulating HDPE composite material is obtained. The preparation method of the flame-retardant TPE composite material is as follows: Polyethylene, polyphenylene sulfide, and compatibilizer masterbatch are mixed at 70-80℃ and 200-300rpm for 3-7 minutes. Then, flame retardant masterbatch, antioxidant 1010, and antioxidant 168 are added, and the mixture is continued for 10-15 minutes. The mixture is then transferred to an internal mixer. Cumene peroxide and triallyl isocyanurate are added to methyl silicone oil, heated to 50-60℃, and stirred continuously for 20-30 minutes to dissolve the mixture. Methyl vinyl silane and the mixture are then added to the internal mixer and kneaded at 160-170℃ for 3-7 minutes. After kneading, the mixture is transferred to a screw extruder for extrusion and granulation. The die head temperature is controlled at 140-150℃ to obtain the flame-retardant TPE composite material.

2. The method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable according to claim 1, characterized in that: By weight, the insulating HDPE composite material includes 35-45 parts high-density polyethylene, 0.35-0.45 parts maleic anhydride, 0.1-0.3 parts antioxidant 1010, 0.5-1.0 parts benzophenone, 0.2-0.5 parts tripropylene cyanurate, 0.1-0.3 parts propylene oxyacetophenone, and 4.0-6.0 parts composite thermally conductive and insulating filler; the mass ratio of p-hydroxyacetophenone to propylene bromide is (9-11):(12-15).

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

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

5. The method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable according to claim 1, 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).

6. The method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable according to claim 1, 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.

7. The method for preparing an ultra-fine, high flame-retardant CAT6A signal transmission cable according to claim 1, characterized in that: By weight, the flame-retardant TPE composite material comprises 50-60 parts polyethylene, 17-22 parts polyphenylene sulfide, 15-20 parts compatibilizer masterbatch, 35-40 parts flame retardant masterbatch, 0.3-0.5 parts antioxidant 1010, 0.2-0.5 parts antioxidant 168, 30-40 parts methyl vinyl silane, 0.8-1.2 parts cumene peroxide, and 0.5-1.0 parts triallyl isocyanurate.

8. The ultra-fine, high flame-retardant CAT6A signal transmission cable prepared by the method according to any one of claims 1-7, characterized in that: The cable has a conductor diameter of 34AWG and possesses signal integrity transmission performance through TIA Patch Cord Cat6A 15.0m.

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