Fireproof, waterproof and anti-creeping wire and cable and production process thereof

Abstract

The invention discloses a fireproof, waterproof and anti-creeping wire and cable and a production process thereof, and belongs to the technical field of cable production, and the fireproof, waterproof and anti-creeping wire and cable sequentially comprises a conductor, a double-layer insulating layer, a waterproof layer, a shielding layer and a double-layer outer protective layer from inside to outside; wherein the inner layer of the double-layer insulating layer is made of ceramic silicone rubber; the outer layer of the double-layer insulating layer is cross-linked polyethylene; injected glue is contained in the waterproof layer; the materials for glue injection are microcapsule water-absorbent resin and a silane coupling agent KH-550; the inner layer of the outer protective layer is made of phosphorus-nitrogen intumescent flame-retardant EVA; and the outer layer of the outer protective layer is flame-retardant polyvinyl chloride. Meanwhile, the invention provides a production process of the fireproof, waterproof and anti-creeping electric wire and cable, the technical bottleneck that a traditional cable is poor in fireproof, waterproof and anti-creeping comprehensive performance and is split is broken through multi-dimensional cooperation, and it is detected that the electric wire and cable produced through the production process has excellent fireproof, waterproof and anti-creeping performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of cable production, and particularly relates to a fireproof, waterproof and anti-electric leakage wire and cable and its production process. Background Art

[0002] As the core carrier of energy transmission, the application scenarios of wires and cables are becoming increasingly complex. Traditional cables often face the following problems in extreme environments (such as high temperature, humidity, and chemical corrosion): Insufficient fireproof performance: Conventional flame retardant materials (such as PVC) are prone to softening and decomposition at high temperatures, releasing toxic smoke, and having a short fire resistance time (usually ≤ 60 minutes), which cannot meet the safety standards of scenarios such as nuclear power plants and subway tunnels; Weak waterproof design: The single-layer sheath or aluminum-plastic composite tape structure is prone to leakage after long-term immersion in water, resulting in a decrease in insulation performance (the insulation resistance decreases by ≥ 40% after 7 days of immersion), especially affecting the reliability of submarine cables and underground pipe galleries; High risk of electric leakage: Poor grounding of the shielding layer or material deterioration will cause partial discharge (> 10 pC), leading to electrical fires, and data centers and medical facilities are extremely sensitive to such problems. Summary of the Invention

[0003] The purpose of the present invention is to provide a fireproof, waterproof and anti-electric leakage wire and cable and its production process to improve the fireproof, waterproof and anti-electric leakage performance of the wire and cable.

[0004] The purpose of the present invention can be achieved by the following technical solutions: A fireproof, waterproof and anti-electric leakage wire and cable sequentially includes from inside to outside: a conductor, a double-layer insulation layer, a waterproof layer, a shielding layer, and a double-layer outer sheath; The inner layer of the double-layer insulation layer is ceramicized silicone rubber; The outer layer of the double-layer insulation layer is cross-linked polyethylene; The waterproof layer contains injected glue; The material of the injected glue is microcapsule water-absorbing resin and silane coupling agent KH-550; The inner layer of the outer sheath is phosphorus-nitrogen based intumescent flame retardant EVA; The outer layer of the outer sheath is flame retardant polyvinyl chloride.

[0005] Further, the ceramicized silicone rubber layer is composed of the following raw materials in parts by mass: 100 parts of methyl vinyl silicone rubber; 60 parts of aluminum hydroxide; 8 parts of nano-montmorillonite; 0.5 part of platinum catalyst; 2 parts of hydrogen-containing silicone oil cross-linking agent.

[0006] Further, the microcapsule water-absorbing resin is prepared by the following steps: Dissolve the sodium acrylate-acrylamide copolymer in deionized water to obtain the aqueous phase; add Span-80 to cyclohexane and stir until transparent to obtain the oil phase; drop the aqueous phase into the oil phase, shear and emulsify to form a W / O emulsion, then add the polyurethane prepolymer thereto, stir for 30 min, then add 1,4-butanediol thereto, raise the temperature to 55-60 °C, react for 4-5 h, then add glacial acetic acid thereto, and then collect the microcapsules by centrifugation. After the microcapsules are washed, dried and screened, microcapsule water-absorbing resin is obtained.

[0007] Further, the dosage ratio of the sodium acrylate-acrylamide copolymer, deionized water, cyclohexane, Span-80, polyurethane prepolymer, 1,4-butanediol, and glacial acetic acid is 10 g: 100 mL: 300 mL: 3-4 g: 20 g: 1-2 g: 0.5-1 mL.

[0008] Further, the preparation process of the phosphorus-nitrogen intumescent flame retardant EVA is as follows: Premix ammonium polyphosphate, pentaerythritol, melamine and nano-silica, and simultaneously add KH-570. After mixing, obtain the premixed flame retardant. Then add the EVA base material into a kneader and raise the temperature to 90-95 °C, keep the temperature constant and melt and knead for 3 min. After completion, add the premixed flame retardant into the kneader and knead for 8-10 min. After completion, discharge the material, then extrude and pelletize with a twin-screw extruder, and then cool to obtain the phosphorus-nitrogen intumescent flame retardant EVA.

[0009] Further, the mass parts of each raw material in the phosphorus-nitrogen intumescent flame retardant EVA are: 100 parts of EVA base material, 25-30 parts of ammonium polyphosphate, 15-20 parts of pentaerythritol, 10 parts of melamine, 5 parts of nano-silica, and 1.5 parts of silane coupling agent KH-570.

[0010] Further, the preparation process of the flame retardant polyvinyl chloride is as follows: Mix zinc borate powder and titanate coupling agent, then add them to absolute ethanol. After ultrasonic dispersion, drying and sieving, obtain the modified zinc borate; then raise the temperature of PVC resin and dioctyl phthalate to 100 °C and mix for 5 min, then sequentially add calcium stearate, antimony trioxide and modified zinc borate thereto, mix at 110 °C for 10 min, then cool and discharge to obtain the mixture. Then plasticize, thin pass, mold and cool the mixture to obtain the flame retardant polyvinyl chloride.

[0011] Further, the mass parts of each raw material in the flame retardant polyvinyl chloride are: 100 parts of PVC resin, 15 parts of zinc borate, 3-4 parts of antimony trioxide, 30 parts of dioctyl phthalate, 2-3 parts of calcium stearate, and 0.5-1 part of titanate coupling agent NDZ-201.

[0012] Furthermore, a production process for a fireproof, waterproof, and anti-electric leakage wire and cable includes the following steps: S1. After stranding and cleaning the tinned copper single wires, spray graphene slurry, and then dry and cure to obtain a conductor. S2. Co-extrude a double-layer insulation layer on the surface of the conductor. The inner layer is a ceramized silicone rubber layer, and the outer layer is cross-linked polyethylene. After co-extrusion, cross-link and cool to obtain an insulated wire core. S3. Longitudinally wrap the aluminum-plastic tape around the outer peripheral side of the insulated wire core to obtain a longitudinally wrapped insulated wire core. Then, inject glue into the gaps of the aluminum-plastic tape of the longitudinally wrapped insulated wire core through an annular glue injection head to obtain a glue-injected wire core. Extrude a high-density polyethylene inner sheath layer on the outside of the glue-injected wire core to form a waterproof layer and obtain a waterproof wire core. S4. Weave copper wires, wrap and weld copper tapes around the outer peripheral side of the waterproof wire core to form a shielding layer and obtain a shielded wire core. S5. Co-extrude a double-layer outer sheath on the surface of the shielded wire core. The inner layer is a phosphorus-nitrogen-based intumescent flame-retardant EVA, and the outer layer is flame-retardant polyvinyl chloride. After co-extrusion, cool to obtain a fireproof, waterproof, and anti-electric leakage wire and cable.

[0013] Furthermore, the graphene slurry in S1 is an aqueous dispersion with a graphene content of 5 wt%.

[0014] Furthermore, the co-extrusion parameters in S2: The temperature of each zone of the inner extruder: Zone 1 is 160 °C, Zone 2 is 180 °C, Zone 3 is 190 °C, and the head is 200 °C; The temperature of each zone of the outer extruder: Zone 1 is 120 °C, Zone 2 is 130 °C, Zone 3 is 140 °C, and the head is 150 °C.

[0015] Furthermore, the specifications of the aluminum-plastic tape in S3: The aluminum foil thickness is 0.05 mm + the polyimide film thickness is 0.03 mm.

[0016] The beneficial effects of the present invention: The present invention provides a fireproof, waterproof, and anti-electric leakage wire and cable and its production process. Through multi-dimensional coordination, the present invention breaks through the technical bottleneck of the poor and fragmented comprehensive performance of traditional cables in "fire prevention, waterproofing, and electric leakage protection". After testing, the wire and cable produced by the present invention has excellent fireproof, waterproof, and anti-electric leakage performance.

[0017] The principle is as follows: First, the present invention uses nano-montmorillonite to enhance ceramized silicone rubber + phosphorus-nitrogen-based intumescent flame-retardant EVA material + flame-retardant polyvinyl chloride to achieve fire resistance - flame retardancy integration, aiming to improve the fire resistance time of the cable and reduce the smoke toxicity; Then, the present invention uses microcapsule water-absorbing resin + PI film aluminum-plastic tape to achieve dynamic self-repair waterproofing, aiming to solve the problems of cable water leakage and insulation decline when immersed in water; Finally, the present invention uses a graphene-coated conductor + a copper tape shielding layer to achieve long-term electric leakage protection.

[0018] Among them, the present invention uses nano-montmorillonite to intercalate and reinforce ceramizable silicone rubber. During the combustion process, the ceramizable silicone rubber forms a ceramic layer. The addition of nano-montmorillonite improves the density of the ceramic layer, and ultimately improves the fire resistance (Comparative Example 1 (without nano-montmorillonite): the fire resistance time decreases by 34%). The phosphorus-nitrogen intumescent flame retardant EVA forms an intumescent carbon layer during combustion, which can assist in improving the fire resistance. The outer flame retardant polyvinyl chloride also has flame retardant properties. The three work together to achieve the improvement of fire protection performance.

[0019] Among them, the present invention prepares a microcapsule resin. When the cable is in a water immersion environment, the PI film aluminum-plastic tape provides primary waterproofing. The microcapsules rupture when exposed to water and release the water-absorbing resin to achieve further waterproofing, and also achieve dynamic repair of cracks to ensure water tightness (Example 11 has 0 leakage points, Comparative Example 2 has 2 leakage points per meter). At the same time, when the cable is in a high-temperature environment, the ceramic layer forms a physical barrier, and the microcapsules rupture more quickly when heated, releasing the water-absorbing resin to fill the ceramic cracks and prevent the penetration of flames (Example 11 has a fire resistance time of 125 minutes, Comparative Example 2 has a fire resistance time of 113 minutes).

[0020] Among them, the graphene on the graphene-coated conductor can reduce the contact resistance, and the copper tape shielding layer blocks external interference. The two work together to achieve low leakage (<0.5 pC) and high shielding (≥85 dB) of the cable.

[0021] Finally, through the deep coupling of the three innovation points of fire resistance - waterproofing - leakage protection, the present invention solves the systematic defects of traditional cables in extreme environments, and there is an inseparable synergistic relationship between the improvement points. The technical solution of the present invention has also achieved significant improvements in core indicators such as fire resistance time, waterproofness, and smoke suppression. Detailed Embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0023] Example 1

[0024] Prepare microcapsule water-absorbing resin: Dissolve sodium acrylate-acrylamide copolymer (10 g, CAS 25987-30-8, molecular weight 3 million, water absorption ratio ≥ 50 times) in 100 mL of deionized water to obtain an aqueous phase; add emulsifier Span-80 (3 g, HLB = 4.3) to cyclohexane (300 mL, analytical pure), stir until transparent to obtain an oil phase; slowly drop the aqueous phase into the oil phase while performing high-shear emulsification (8000 rpm, 10 min) to form a W / O emulsion (droplet particle size 50 ± 5 μm); then add polyurethane prepolymer (20 g, NCO content 8% - 10%, purchased from Bayer, model Desmodur® L75) to the emulsified W / O emulsion, reduce the stirring speed to 500 rpm, and continue for 30 min to uniformly adsorb the prepolymer on the surface of the emulsion droplets. Then add chain extender 1,4-butanediol (1 g, purity ≥ 99.5%), raise the temperature to 55 °C, and react for 4 h to complete chain extension to form a polyurethane shell layer. Then add glacial acetic acid (0.5 mL) to quench the unreacted NCO groups to obtain a reaction solution. Centrifuge the reaction solution (3000 rpm, 10 min), discard the upper oil phase to obtain microcapsules, wash the microcapsules with cyclohexane (100 mL × 3 times) to remove residual emulsifier, then send the wet capsule suspension into a spray drying tower with an inlet temperature of 180 °C and an outlet temperature of 80 °C, collect the dry powder (water content ≤ 3%), and then classify it through a vibrating screen (mesh number 300 mesh) to obtain microcapsule water-absorbing resin with a particle size of 50 ± 5 μm.

[0025] Example 2

[0026] Preparation of microcapsule water-absorbing resin: Dissolve sodium acrylate-acrylamide copolymer (10 g, CAS 25987-30-8, molecular weight 3 million, water absorption ratio ≥ 50 times) in 100 mL of deionized water to obtain an aqueous phase; add emulsifier Span-80 (4 g, HLB = 4.3) to cyclohexane (300 mL, analytical grade), stir until transparent to obtain an oil phase; slowly drip the aqueous phase into the oil phase while performing high-shear emulsification (8000 rpm, 10 min) to form a W / O emulsion (droplet particle size 50 ± 5 μm); then add polyurethane prepolymer (20 g, NCO content 8% - 10%, purchased from Bayer, model Desmodur® L75) to the emulsified W / O emulsion, reduce the stirring speed to 500 rpm, and continue for 30 min to allow the prepolymer to be evenly adsorbed on the surface of the emulsion droplets. Then add chain extender 1,4-butanediol (2 g, purity ≥ 99.5%), raise the temperature to 55 °C, and react for 5 h to complete chain extension to form a polyurethane shell layer. Then add glacial acetic acid (0.8 mL) to quench the unreacted NCO groups to obtain a reaction solution. Centrifuge the reaction solution (3000 rpm, 10 min), discard the upper oil phase to obtain microcapsules, wash the microcapsules with cyclohexane (100 mL × 3 times) to remove residual emulsifier, then send the wet capsule suspension into a spray drying tower with an inlet temperature of 180 °C and an outlet temperature of 80 °C, collect the dry powder (water content ≤ 3%), and then classify it through a vibrating screen (mesh number 300) to obtain microcapsule water-absorbing resin with a particle size of 50 ± 5 μm.

[0027] Example 3

[0028] Preparation of microcapsule water-absorbing resin: Dissolve sodium acrylate-acrylamide copolymer (10 g, CAS 25987-30-8, molecular weight 3 million, water absorption ratio ≥ 50 times) in 100 mL of deionized water to obtain an aqueous phase; add emulsifier Span-80 (4 g, HLB = 4.3) to cyclohexane (300 mL, analytical pure), stir until transparent to obtain an oil phase; slowly drip the aqueous phase into the oil phase while performing high-shear emulsification (8000 rpm, 10 min) to form a W / O emulsion (droplet particle size 50 ± 5 μm); then add polyurethane prepolymer (20 g, NCO content 8% - 10%, purchased from Bayer, model Desmodur® L75) to the emulsified W / O emulsion, reduce the stirring speed to 500 rpm, and continue for 30 min to allow the prepolymer to be evenly adsorbed on the surface of the emulsion droplets. Then add chain extender 1,4-butanediol (2 g, purity ≥ 99.5%) thereto, raise the temperature to 60 °C, and react for 5 h to complete chain extension to form a polyurethane shell layer. Then add glacial acetic acid (1 mL) to quench the unreacted NCO groups to obtain a reaction solution. Centrifuge the reaction solution (3000 rpm, 10 min), discard the upper oil phase to obtain microcapsules, wash the microcapsules with cyclohexane (100 mL × 3 times) to remove residual emulsifier, then send the wet capsule suspension into a spray drying tower with an inlet temperature of 180 °C and an outlet temperature of 80 °C, collect the dry powder (water content ≤ 3%), and then classify it through a vibrating sieve (mesh number 300 mesh) to obtain a microcapsule water-absorbing resin with a particle size of 50 ± 5 μm.

[0029] Example 4

[0030] Prepare a phosphorus-nitrogen intumescent flame-retardant EVA: First, weigh the following raw materials according to parts by mass: 100 parts of EVA base material (VA content 28%, melt index 2 g / 10 min (190 °C / 2.16 kg)), 25 parts of ammonium polyphosphate (APP, molecular weight 1000), 15 parts of pentaerythritol (PER, purity ≥ 98%, particle size D50 = 10 μm), 10 parts of melamine (MEL, purity ≥ 99.5%, whiteness ≥ 95%), 5 parts of nano-silica (particle size 20 nm, specific surface area 200 m 2 / g), 1.5 parts of silane coupling agent KH-570.

[0031] Then, ammonium polyphosphate, pentaerythritol, melamine and nano-silica were premixed in a high-speed mixer (1200 rpm, 10 min), and KH-570 was added simultaneously. After mixing, a premixed flame retardant was obtained. The EVA base material was added to an internal mixer and heated to 90 °C, and then melt-mixed at a constant temperature for 3 min. After that, the premixed flame retardant was added to the internal mixer, the mixing pressure was adjusted to 0.5 MPa, the rotation speed was 50 rpm, and the mixture was kneaded for 8 min. After completion, the material was discharged and then granulated by twin-screw extrusion (temperature setting: zone 1 120 °C, zone 2 140 °C, zone 3 160 °C, die head 150 °C; screw rotation speed 200 rpm). After completion, it was cooled to obtain phosphorus-nitrogen intumescent flame-retardant EVA.

[0032] Example 5

[0033] Preparation of phosphorus-nitrogen intumescent flame-retardant EVA: First, the following raw materials were weighed according to parts by mass: 100 parts of EVA base material (VA content 28%, melt index 2 g / 10 min (190 °C / 2.16 kg)), 28 parts of ammonium polyphosphate (APP, molecular weight 1000), 20 parts of pentaerythritol (PER, purity ≥ 98%, particle size D50 = 10 μm), 10 parts of melamine (MEL, purity ≥ 99.5%, whiteness ≥ 95%), 5 parts of nano-silica (particle size 20 nm, specific surface area 200 m 2 / g), 1.5 parts of silane coupling agent KH-570.

[0034] Then, ammonium polyphosphate, pentaerythritol, melamine and nano-silica were premixed in a high-speed mixer (1200 rpm, 10 min), and KH-570 was added simultaneously. After mixing, a premixed flame retardant was obtained. The EVA base material was added to an internal mixer and heated to 90 °C, and then melt-mixed at a constant temperature for 3 min. After that, the premixed flame retardant was added to the internal mixer, the mixing pressure was adjusted to 0.55 MPa, the rotation speed was 55 rpm, and the mixture was kneaded for 10 min. After completion, the material was discharged and then granulated by twin-screw extrusion (temperature setting: zone 1 120 °C, zone 2 140 °C, zone 3 160 °C, die head 150 °C; screw rotation speed 200 rpm). After completion, it was cooled to obtain phosphorus-nitrogen intumescent flame-retardant EVA.

[0035] Example 6 Preparation of phosphorus-nitrogen intumescent flame-retardant EVA:

[0036] First, weigh the following raw materials by parts by mass: 100 parts of EVA base material (VA content 28%, melt index 2 g / 10 min (190 °C / 2.16 kg)), 30 parts of ammonium polyphosphate (APP, molecular weight 1000), 20 parts of pentaerythritol (PER, purity ≥98%, particle size D50 = 10 μm), 10 parts of melamine (MEL, purity ≥99.5%, whiteness ≥95%), 5 parts of nano-silica (particle size 20 nm, specific surface area 200 m 2 / g), 1.5 parts of silane coupling agent KH-570.

[0037] Then, premix ammonium polyphosphate, pentaerythritol, melamine and nano-silica in a high-speed mixer (1200 rpm, 10 min), and at the same time add KH-570. After mixing, a premixed flame retardant is obtained; add the EVA base material to an internal mixer and heat up to 95 °C, keep the temperature constant and melt and mix for 3 min. After completion, add the premixed flame retardant to the internal mixer, adjust the mixing pressure to 0.6 MPa and the rotation speed to 60 rpm, and mix for 10 min. After completion, discharge the material, and then extrude and pelletize with a twin-screw extruder (temperature setting: zone 1 120 °C, zone 2 140 °C, zone 3 160 °C, die head 150 °C; screw rotation speed 200 rpm). After completion, cool it to obtain phosphorus-nitrogen intumescent flame retardant EVA.

[0038] Example 7

[0039] Prepare flame-retardant polyvinyl chloride: First, weigh the following raw materials by parts by mass: 100 parts of PVC resin (SG-5 type, K value 65 - 67), 15 parts of zinc borate (ZB, particle size D50 = 5 μm, ZnO content 37% - 40%), 3 parts of antimony trioxide (purity ≥99.8%, particle size D50 = 1 μm), 30 parts of dioctyl phthalate (flash point 200 °C, acid value 0.1 mg KOH / g), 2 parts of calcium stearate (purity ≥98%, free acid ≤0.5%), 0.5 part of titanate coupling agent NDZ-201.

[0040] Then, after mixing zinc borate powder with titanate coupling agent, add it to absolute ethanol (solid-liquid ratio 1:3), disperse it by ultrasonic wave (power 300W, 30min), then dry it at 80°C, and sieve it through a 200-mesh sieve to obtain modified zinc borate; then add PVC resin and dioctyl phthalate to a high-speed hot mixer, heat up to 100°C and mix for 5min, then sequentially add calcium stearate, antimony trioxide, and modified zinc borate to the high-speed hot mixer, mix at 110°C for 10min, then transfer the mixed material to a cold mixer, discharge it after cooling to below 50°C to obtain a mixed material, then send the mixed material into a two-roll open mill (front roll 160°C, rear roll 155°C) for plasticization for 10min, thin pass 3 times, and then send it into a flat vulcanizing machine for molding (temperature 170°C, pressure 10MPa, time 5min), and after cooling, flame-retardant polyvinyl chloride is prepared.

[0041] Example 8

[0042] Prepare flame-retardant polyvinyl chloride: First, weigh the following raw materials according to parts by mass: 100 parts of PVC resin (SG-5 type, K value 65-67), 15 parts of zinc borate (ZB, particle size D50 = 5μm, ZnO content 37%-40%), 3.5 parts of antimony trioxide (purity ≥99.8%, particle size D50 = 1μm), 30 parts of dioctyl phthalate (flash point 200°C, acid value 0.1mg KOH / g), 3 parts of calcium stearate (purity ≥98%, free acid ≤0.5%), 0.8 part of titanate coupling agent NDZ-201.

[0043] Then, after mixing zinc borate powder with titanate coupling agent, add it to absolute ethanol (solid-liquid ratio 1:4), disperse it by ultrasonic wave (power 300W, 30min), then dry it at 80°C, and sieve it through a 200-mesh sieve to obtain modified zinc borate; then add PVC resin and dioctyl phthalate to a high-speed hot mixer, heat up to 100°C and mix for 5min, then sequentially add calcium stearate, antimony trioxide, and modified zinc borate to the high-speed hot mixer, mix at 110°C for 10min, then transfer the mixed material to a cold mixer, discharge it after cooling to below 50°C to obtain a mixed material, then send the mixed material into a two-roll open mill (front roll 165°C, rear roll 160°C) for plasticization for 10min, thin pass 3 times, and then send it into a flat vulcanizing machine for molding (temperature 170°C, pressure 10MPa, time 10min), and after cooling, flame-retardant polyvinyl chloride is prepared.

[0044] Example 9

[0045] Prepare flame-retardant polyvinyl chloride: First, weigh the following raw materials by parts by mass: 100 parts of PVC resin (SG-5 type, K value 65-67), 15 parts of zinc borate (ZB, particle size D50 = 5 μm, ZnO content 37%-40%), 4 parts of antimony trioxide (purity ≥ 99.8%, particle size D50 = 1 μm), 30 parts of dioctyl phthalate (flash point 200 °C, acid value 0.1 mg KOH / g), 3 parts of calcium stearate (purity ≥ 98%, free acid ≤ 0.5%), and 1 part of titanate coupling agent NDZ-201.

[0046] Then, after mixing the zinc borate powder and the titanate coupling agent, add them to anhydrous ethanol (solid-liquid ratio 1:5), ultrasonically disperse (power 300 W, 30 min), then place them in an oven at 80 °C for drying, and pass through a 200-mesh sieve to obtain modified zinc borate; then add the PVC resin and dioctyl phthalate to a high-speed heat mixer, heat up to 100 °C and mix for 5 min, then sequentially add calcium stearate, antimony trioxide, and modified zinc borate to the high-speed heat mixer, mix at 110 °C for 10 min, then transfer the mixed material to a cold mixer, cool down to below 50 °C and discharge to obtain a mixed material, and then feed the mixed material into a two-roll mill (front roll 165 °C, rear roll 160 °C) for plasticization for 10 min, thin pass 3 times, and then feed it into a flat vulcanizing machine for molding (temperature 180 °C, pressure 10 MPa, time 10 min), and after cooling, flame-retardant polyvinyl chloride is prepared.

[0047] Example 10

[0048] Production of fireproof, waterproof and anti-electric leakage wires and cables: 1. Conductor layer: (1) Stranding: Stranding the tinned copper single wires (diameter 2.0 mm, coating thickness 4 μm) according to the GB / T 3956 standard, and controlling the stranding pitch diameter ratio at 10 times to obtain a stranded wire.

[0049] (2) Surface cleaning: Pass the stranded wire through an electro-degreasing tank (NaOH solution, concentration 50 g / L, temperature 60 °C, time 30 s) to remove the surface oxides and grease.

[0050] (3) Graphene coating: Adopt the plasma spraying process, and set the parameters of plasma spraying as follows: Power: 60 kW, frequency 40 kHz; Argon flow rate: 12 L / min, pressure 0.3 MPa; Graphene slurry: An aqueous dispersion with a graphene content of 5 wt%, spraying speed 10 m / min; Coating thickness: 5 μm.

[0051] Drying and curing: Infrared tunnel furnace (temperature 120 °C, speed 8 m / min, curing time 8 s) to make the coating form a dense conductive film and form a conductor.

[0052] 2. Coextrusion molding of the insulating layer: (1) Double-layer coextrusion: Double-layer insulating layers are coextruded on the surface of the conductor. The thickness of the inner ceramicized silicone rubber layer is 0.55 mm, and the thickness of the outer cross-linked polyethylene layer is 0.65 mm. Among them, the parameters of the double-layer extruder are set as follows: Temperatures of each zone of the inner extruder: Zone 1: 160 °C, Zone 2: 180 °C, Zone 3: 190 °C, head: 200 °C; Temperatures of each zone of the outer extruder: Zone 1: 120 °C, Zone 2: 130 °C, Zone 3: 140 °C, head: 150 °C. After coextrusion, a coextruded body is obtained, and then cross-linking treatment is carried out, that is, the coextruded body is sent into a nitrogen cross-linking pipeline (pressure 1 MPa, temperature 320 °C, time 20 s) for nitrogen cross-linking treatment, and after cooling, an insulated wire core is obtained.

[0053] (2) Inner layer material: Ceramicized silicone rubber (100 parts (parts by mass; the same below) of methyl vinyl silicone rubber (model: SILASTIC® MVQ, Mooney viscosity ML(1+4) 125 °C = 30 - 50, purchased from Dow Chemical Company, USA), 60 parts of aluminum hydroxide (particle size distribution: D50 = 2.0 μm, purity ≥ 99.8%), 8 parts of nano-montmorillonite (particle size 30 nm, specific surface area 50 m² / g), 0.5 part of platinum catalyst (model: PC-072, purchased from Nanjing Kangmanlin Chemical Co., Ltd.), 2 parts of hydrogen-containing silicone oil cross-linking agent (model: HMS-991, purchased from Bluestar Silicones Co., Ltd.)).

[0054] (3) Outer layer material: Cross-linked polyethylene (XLPE, density at 23 °C 0.92 g / cm 3 ).

[0055] 3. Lamination of the waterproof layer: (1) Longitudinal wrapping of the aluminum-plastic composite tape: The aluminum-plastic tape is longitudinally wrapped around the outer peripheral side of the insulated wire core. After completion, a longitudinally wrapped insulated wire core is obtained.

[0056] Specifications of the aluminum-plastic tape: Aluminum foil thickness 0.05 mm + polyimide (PI) film thickness 0.03 mm, width = circumference of the insulated wire core × 1.15 (lap rate 15%).

[0057] Longitudinal wrapping molding: The forming die has a cone angle of 30°, and the strip tension is 8 N / mm 2 , and the lap joint is high-frequency welded (power 2 kW, frequency 27 MHz).

[0058] (2) Injection of the water-swellable adhesive: The water-swellable adhesive is injected through an annular injection head into the gap between the aluminum-plastic tapes of the longitudinally wrapped insulated wire core. Among them, the injection amount is 8 g / m, and it is left standing at room temperature for 20 min to form an injection-molded wire core.

[0059] Colloid ratio: Microcapsule water-absorbing resin prepared in Example 1 + 1 wt% silane coupling agent KH-550 (purchased from Sinopharm Chemical Reagent Co., Ltd.); (3) Extrusion of HDPE inner sheath: Extrude a high-density polyethylene (HDPE, density 0.954 g / cm 3 , melt flow rate 0.9 g / 10 min) inner sheath layer on the outside of the injection core wire using a screw extruder, with the thickness controlled at 1.2 mm to form a waterproof layer, obtaining a waterproof core wire.

[0060] Temperature of the screw extruder: Zone 1 180 °C, Zone 2 190 °C, Zone 3 200 °C, head 210 °C.

[0061] 4. Shield layer processing: (1) Weave copper wires on the outer peripheral side of the waterproof core wire so that the copper wire coverage rate ≥ 85%. After actual measurement, the coverage rate in this example reaches 85%. Then, wrap with copper tape so that the wrap overlap rate ≥ 25%. After actual measurement, the wrap overlap rate in this example reaches 25%. After welding, a shield layer is formed to obtain a shielded core wire.

[0062] (2) Copper wire specifications: diameter 0.10 mm, soft-state oxygen-free copper (purity ≥ 99.99%); Weaving parameters: 36-spindle weaving machine, spindle speed 1200 rpm, weaving angle 45 ± 2°.

[0063] (3) Copper tape specifications: thickness 0.10 mm, width 25 mm; Wrap tension: 2.0 N / mm 2 .

[0064] 5. Outer sheath extrusion: (1) Double-layer co-extrusion: Co-extrude a double-layer outer sheath on the surface of the shielded core wire. The thickness of the inner low-smoke halogen-free polyolefin layer is 0.75 mm, and the thickness of the outer flame-retardant polyvinyl chloride layer is 1.1 mm. Among them, the parameters of the double-layer extruder are set as follows: Temperatures of each zone of the inner extruder: Zone 1 150 °C, Zone 2 160 °C, Zone 3 170 °C, head 180 °C; Temperatures of each zone of the outer extruder: Zone 1 130 °C, Zone 2 140 °C, Zone 3 150 °C, head 160 °C. After co-extrusion, it is cooled to obtain a fireproof, waterproof, and anti-electric leakage wire and cable.

[0065] (2) Inner layer material: Phosphorus-nitrogen-based intumescent flame-retardant EVA prepared in Example 4.

[0066] (3) Outer layer material: Flame-retardant polyvinyl chloride prepared in Example 7.

[0067] Example 11 Production of fireproof, waterproof, and anti-electric leakage wire and cable: 1. Conductor layer: (1) Stranding: Stranding the tinned copper single wires (diameter 2.5 mm, coating thickness 4 μm) according to the GB / T 3956 standard, with the stranding pitch diameter ratio controlled at 12 times to obtain the stranded wire.

[0068] (2) Surface cleaning: Pass the stranded wire through an electro-chemical degreasing tank (NaOH solution, concentration 50 g / L, temperature 60 °C, time 30 s) to remove surface oxides and grease.

[0069] (3) Graphene coating: Adopt the plasma spraying process, and the parameters of plasma spraying are set as follows: Power: 60 kW, frequency 40 kHz; Argon flow rate: 14 L / min, pressure 0.3 MPa; Graphene slurry: An aqueous dispersion with a graphene content of 5 wt%, spraying speed 10 m / min; Coating thickness: 10 μm.

[0070] Drying and curing: Infrared tunnel furnace (temperature 120 °C, speed 8 m / min, curing time 10 s) to form a dense conductive film on the coating and form a conductor.

[0071] 2. Insulation layer co-extrusion molding: (1) Double-layer co-extrusion: Co-extrude a double-layer insulation layer on the surface of the conductor. The thickness of the inner ceramicized silicone rubber layer is 0.60 mm, and the thickness of the outer cross-linked polyethylene layer is 0.70 mm. Among them, the parameters of the double-layer extruder are set as follows: Temperatures of each zone of the inner extruder: Zone 1 160 °C, Zone 2 180 °C, Zone 3 190 °C, die head 200 °C; Temperatures of each zone of the outer extruder: Zone 1 120 °C, Zone 2 130 °C, Zone 3 140 °C, die head 150 °C. After co-extrusion, a co-extruded body is obtained, and then cross-linking treatment is carried out, that is, the co-extruded body is sent into a nitrogen cross-linking pipeline (pressure 1.2 MPa, temperature 340 °C, time 30 s) for nitrogen cross-linking treatment, and after cooling, an insulated wire core is obtained.

[0072] (2) Inner layer material: Ceramicized silicone rubber (100 parts (parts by mass; the same below) of methyl vinyl silicone rubber (model: SILASTIC® MVQ, Mooney viscosity ML(1+4) 125 °C = 30 - 50, purchased from Dow Chemical Company, USA), 60 parts of aluminum hydroxide (particle size distribution: D50 = 2.0 μm, purity ≥ 99.8%), 8 parts of nano-montmorillonite (particle size 30 nm, specific surface area 50 m² / g), 0.5 part of platinum catalyst (model: PC-072, purchased from Nanjing Kangmanlin Chemical Co., Ltd.), 2 parts of hydrogen-containing silicone oil cross-linking agent (model: HMS-991, purchased from Bluestar Silicones Co., Ltd.)).

[0073] (3) Outer layer material: Cross-linked polyethylene (XLPE, density at 23 °C 0.92 g / cm3 )。

[0074] 3. Waterproof layer compounding: (1) Longitudinal wrapping of aluminum-plastic composite tape: The aluminum-plastic tape is longitudinally wrapped around the outer peripheral side of the insulated wire core. After completion, a longitudinally wrapped insulated wire core is obtained.

[0075] Specification of aluminum-plastic tape: Aluminum foil thickness 0.05 mm + polyimide (PI) film thickness 0.03 mm, width = circumference of insulated wire core × 1.15 (lap rate 15%).

[0076] Longitudinal wrapping forming: Forming die cone angle 30°, strip tension 8 N / mm 2 , and high-frequency welding (power 2 kW, frequency 27 MHz) at the lap joint.

[0077] (2) Injection of water-swellable glue: Glue is injected through an annular glue injection head into the gap between the aluminum-plastic tapes of the longitudinally wrapped insulated wire core. Among them, the glue injection amount is 9 g / m, and it is left standing at room temperature for 30 min to form a glue-injected wire core.

[0078] Colloid ratio: Microcapsule water-absorbing resin prepared in Example 2 + 1 wt% silane coupling agent KH-550 (purchased from Sinopharm Chemical Reagent Co., Ltd.); (3) Extrusion of HDPE inner sheath: A high-density polyethylene (HDPE, density 0.954 g / cm 3 , melt flow rate 0.9 g / 10 min) inner sheath layer is extruded on the outside of the glue-injected wire core, and the thickness is controlled at 1.2 mm to form a waterproof layer, obtaining a waterproof wire core.

[0079] Temperatures of the screw extruder: Zone 1 180 °C, Zone 2 190 °C, Zone 3 200 °C, head 210 °C.

[0080] 4. Shielding layer processing: (1) Copper wires are woven on the outer peripheral side of the waterproof wire core so that the copper wire coverage rate ≥ 85%. After actual measurement, the coverage rate in this example reaches 87%. Then copper tape is wound so that the winding overlap rate ≥ 25%. After actual measurement, the winding overlap rate in this example reaches 30%. After welding, a shielding layer is formed to obtain a shielded wire core.

[0081] (2) Copper wire specification: Diameter 0.15 mm, soft-state oxygen-free copper (purity ≥ 99.99%); Weaving parameters: 36-spindle weaving machine, spindle speed 1200 rpm, weaving angle 45 ± 2°.

[0082] (3) Copper tape specification: Thickness 0.10 mm, width 25 mm; Winding tension: 2.5 N / mm 2 。

[0083] 5. Outer sheath extrusion: (1) Double-layer co-extrusion: Co-extrude a double-layer outer sheath on the surface of the shielded core. The thickness of the inner low-smoke halogen-free polyolefin layer is 0.80 mm, and the thickness of the outer flame-retardant polyvinyl chloride layer is 1.2 mm. Among them, the parameters of the double-layer extruder are set as follows: Temperatures of each zone of the inner extruder: Zone 1: 150 °C, Zone 2: 160 °C, Zone 3: 170 °C, die head: 180 °C; Temperatures of each zone of the outer extruder: Zone 1: 130 °C, Zone 2: 140 °C, Zone 3: 150 °C, die head: 160 °C. After co-extrusion, it is cooled to obtain the fireproof, waterproof and anti-electric leakage wire and cable.

[0084] (2) Inner layer material: The phosphorus-nitrogen intumescent flame-retardant EVA prepared in Example 5.

[0085] (3) Outer layer material: The flame-retardant polyvinyl chloride prepared in Example 8.

[0086] Example 12

[0087] Production of fireproof, waterproof and anti-electric leakage wire and cable: 1. Conductor layer: (1) Stranding: Stranding the tinned copper single wires (diameter 2.5 mm, coating thickness 4 μm) according to the GB / T 3956 standard, and controlling the stranding pitch-diameter ratio at 14 times to obtain the stranded wire.

[0088] (2) Surface cleaning: Pass the stranded wire through an electro-chemical degreasing tank (NaOH solution, concentration 50 g / L, temperature 60 °C, time 30 s) to remove the surface oxides and grease.

[0089] (3) Graphene coating: Adopt the plasma spraying process, and the parameters of plasma spraying are set as follows: Power: 60 kW, frequency 40 kHz; Argon flow rate: 15 L / min, pressure 0.3 MPa; Graphene slurry: An aqueous dispersion with a graphene content of 5 wt%, spraying speed 10 m / min;

[0090] Coating thickness: 10 μm.

[0091] Drying and curing: Infrared tunnel furnace (temperature 120 °C, speed 8 m / min, curing time 10 s) to make the coating form a dense conductive film and form the conductor.

[0092] 2. Insulation layer co-extrusion molding: (1) Double-layer co-extrusion: Two insulating layers are co-extruded on the surface of the conductor. The thickness of the inner ceramicized silicone rubber layer is 0.60 mm, and the thickness of the outer cross-linked polyethylene layer is 0.70 mm. Among them, the parameters of the double-layer extruder are set as follows: Temperatures of each zone of the inner extruder: Zone 1: 160 °C, Zone 2: 180 °C, Zone 3: 190 °C, head: 200 °C; Temperatures of each zone of the outer extruder: Zone 1: 120 °C, Zone 2: 130 °C, Zone 3: 140 °C, head: 150 °C. After co-extrusion, a co-extruded body is obtained, and then cross-linking treatment is carried out, that is, the co-extruded body is sent into a nitrogen cross-linking pipeline (pressure 1.2 MPa, temperature 350 °C, time 30 s) for nitrogen cross-linking treatment, and after cooling, an insulated wire core is obtained.

[0093] (2) Inner layer material: Ceramicized silicone rubber (100 parts (parts by mass; the same below) of methyl vinyl silicone rubber (model: SILASTIC® MVQ, Mooney viscosity ML(1+4) 125 °C = 30 - 50, purchased from Dow Chemical Company, USA), 60 parts of aluminum hydroxide (particle size distribution: D50 = 2.0 μm, purity ≥ 99.8%), 8 parts of nano-montmorillonite (particle size 30 nm, specific surface area 50 m² / g), 0.5 part of platinum catalyst (model: PC-072, purchased from Nanjing Kangmanlin Chemical Co., Ltd.), 2 parts of hydrogen-containing silicone oil cross-linking agent (model: HMS-991, purchased from Bluestar Silicones Co., Ltd.)).

[0094] (3) Outer layer material: Cross-linked polyethylene (XLPE, density at 23 °C is 0.92 g / cm 3 ).

[0095] 3. Waterproof layer lamination:

[0096] (1) Longitudinal wrapping of aluminum-plastic composite tape: The aluminum-plastic tape is longitudinally wrapped around the outer periphery of the insulated wire core. After completion, a longitudinally wrapped insulated wire core is obtained.

[0097] Specifications of the aluminum-plastic tape: Aluminum foil thickness 0.05 mm + polyimide (PI) film thickness 0.03 mm, width = circumference of the insulated wire core × 1.15 (lap rate 15%).

[0098] Longitudinal wrapping forming: Forming die cone angle 30 °, strip tension 8 N / mm 2 , and high-frequency welding (power 2 kW, frequency 27 MHz) is carried out at the lap joint.

[0099] (2) Injection of water-swellable glue: Glue is injected into the gap between the aluminum-plastic tapes of the longitudinally wrapped insulated wire core through an annular glue injection head. Among them, the injection volume is 10 g / m, and it is left standing at room temperature for 30 min to form an injected glue wire core.

[0100] Colloid ratio: Microcapsule water-absorbing resin prepared in Example 3 + 1 wt% silane coupling agent KH-550 (purchased from Sinopharm Chemical Reagent Co., Ltd.); (3) Extrusion of HDPE inner sheath: Using a screw extruder, extrude a high-density polyethylene (HDPE, density 0.954 g / cm 3 , melt flow rate 0.9 g / 10 min) inner sheath layer on the outer side of the injected core wire, with the thickness controlled at 1.2 mm to form a waterproof layer, obtaining a waterproof core wire.

[0101] Temperatures of the screw extruder: Zone 1 at 180 °C, Zone 2 at 190 °C, Zone 3 at 200 °C, and the head at 210 °C.

[0102] 4. Shield layer processing: (1) Weave copper wires on the outer peripheral side of the waterproof core wire so that the copper wire coverage rate ≥ 85%. After actual measurement, the coverage rate in this embodiment reaches 88%. Then, perform copper tape wrapping so that the wrapping overlap rate ≥ 25%. After actual measurement, the wrapping overlap rate in this embodiment reaches 30%. After welding, form a shield layer to obtain a shielded core wire.

[0103] (2) Copper wire specifications: diameter 0.20 mm, soft state oxygen-free copper (purity ≥ 99.99%); weaving parameters: 36-spindle weaving machine, spindle speed 1200 rpm, weaving angle 45 ± 2°.

[0104] (3) Copper tape specifications: thickness 0.10 mm, width 25 mm; wrapping tension: 2.5 N / mm 2 .

[0105] 5. Outer sheath extrusion: (1) Double-layer co-extrusion: Co-extrude a double-layer outer sheath on the surface of the shielded core wire. The thickness of the inner low-smoke and halogen-free polyolefin layer is 0.80 mm, and the thickness of the outer flame-retardant polyvinyl chloride layer is 1.2 mm. Among them, the parameters of the double-layer extruder are set as follows: Temperatures of the inner extruder in each zone: Zone 1 at 150 °C, Zone 2 at 160 °C, Zone 3 at 170 °C, and the head at 180 °C; Temperatures of the outer extruder in each zone: Zone 1 at 130 °C, Zone 2 at 140 °C, Zone 3 at 150 °C, and the head at 160 °C. After co-extrusion, then cool to obtain a fireproof, waterproof, and anti-electric leakage wire and cable.

[0106] (2) Inner layer material: Phosphorus-nitrogen-based intumescent flame-retardant EVA prepared in Example 6.

[0107] (3) Outer layer material: Flame-retardant polyvinyl chloride prepared in Example 9.

[0108] Comparative Example 1

[0109] Comparative Example 1 is the control group of Example 11. Remove 8 parts of nano-montmorillonite (particle size 30 nm, specific surface area 50 m² / g) in the inner layer material of Example 11, and keep the rest of the raw materials, raw material dosages, production processes, and process parameters the same as those in Example 11, and finally obtain a wire and cable

[0110] Comparative Example 2

[0111] Comparative Example 2 was the control group of Example 11. The microcapsule water-absorbing resin prepared in Example 2 of Example 11 was replaced with the raw material sodium acrylate-acrylamide copolymer, and the remaining raw materials, raw material dosages, production processes, and process parameters were all kept the same as those in Example 11, and finally, a wire and cable were obtained.

[0112] Comparative Example 3

[0113] Comparative Example 3 was the control group of Example 11. The phosphorus-nitrogen intumescent flame-retardant EVA prepared in Example 5 of Example 11 was replaced with the raw material EVA base material, and the remaining raw materials, raw material dosages, production processes, and process parameters were all kept the same as those in Example 11, and finally, a wire and cable were obtained.

[0114] Comparative Example 4

[0115] Comparative Example 4 was the control group of Example 11. The flame-retardant polyvinyl chloride prepared in Example 8 of Example 11 was replaced with the raw material PVC resin, and the remaining raw materials, raw material dosages, production processes, and process parameters were all kept the same as those in Example 11, and finally, a wire and cable were obtained.

[0116] Perform performance tests on the wire and cables produced in Examples 10 to 12 and Comparative Examples 1 to 4. The test process is as follows, and the test results are shown in Table 1:

[0117] 1. Fire resistance test (GB / T 19666-2019)

[0118] (1) Test equipment: Vertical burning test chamber (model: CZF-5, Nanjing Huanke Instruments); Insulation resistance tester (HP4339B, accuracy ±1%); Thermocouple temperature measurement system (K type, range 0 to 1200 °C).

[0119] (2) Test samples: Cut 3 groups of 1.5 m cable samples, and strip the sheath at both ends to expose the conductor (length 100 mm).

[0120] (3) Test steps: a. Fire resistance time test: Fix the sample vertically in the combustion chamber, align the flame jet port with the middle of the sample (the gas is propane, flow rate 1.5 L / min); Start combustion and maintain the flame temperature at 950 °C (monitored by thermocouple in real time); Record the time from the start of combustion to the breakdown of the insulation layer (insulation resistance <0.1 MΩ / km), and take the average of 3 groups.

[0121] b. Afterflame time test: After burning for 3 h, turn off the fire source and immediately stop the air supply; Use a high-speed camera (1000 fps) to record the time required for the open fire on the surface of the sample to go out.

[0122] c. Insulation Resistance Test: After cooling to room temperature, apply a 500V DC voltage using an insulation resistance tester to measure the resistance between the conductor and the shield layer (test duration: 1 min).

[0123] 2. Waterproof Performance Test (IEC 60811-2-1)

[0124] (1) Test Equipment: Constant Temperature Water Immersion Tank (accuracy ±1°C, Shenzhen Kebiao Instruments); Insulation Resistance Tester (TH2683A, Changzhou Tonghui); Microscope (OLYMPUS BX53, magnification 200×).

[0125] (2) Test Samples: Cut 3 groups of 2m cable samples.

[0126] (3) Test Procedures: Water Immersion Treatment: Immerse the samples completely in deionized water at 25 ± 2°C, with a water depth of 1.0 ± 0.1m; for 30 days, change the water every 24h.

[0127] a. Insulation Resistance Measurement: Take out the samples, dry the surface, apply a 500V DC voltage, measure the resistance between the conductor and the shield layer, and calculate the resistance reduction rate: ΔR = (R0 - R1) / R0 × 100% (R0 is the initial resistance).

[0128] b. Leakage Point Detection: Apply a water pressure of 0.3MPa to the samples (GB / T 3048.10), and maintain for 1h; cut open the sheath, and observe the water seepage marks in the aluminum-plastic tape gap with a microscope (the leakage point is defined as a water stain with a diameter ≥ 0.1mm).

[0129] 3. Electric Leakage Protection Test (IEC 60270)

[0130] (1) Test Equipment: Partial Discharge Detector (PDCheck, Haefely Trench); Shielding Effectiveness Test System (Eaton 6900, frequency range 1MHz - 3GHz); Constant Temperature and Humidity Chamber (temperature 23 ± 1°C, humidity 50 ± 5%).

[0131] (2) Test Samples: Cut 3 groups of 10m cable samples.

[0132] (3) Test Procedures: a. Partial Discharge Quantity Test: Apply a voltage of 1.5U0 (U0 = 0.6kV, i.e., 0.9kV), with a voltage rise rate of 1kV / s; use a calibrated capacitive coupling sensor to record the peak discharge quantity (pC).

[0133] b. Shielding Effectiveness Test: Place the samples in an electromagnetic shielding room, connect one end to a signal generator (output field strength 1V / m, 1GHz), and the other end to a spectrum analyzer; Shielding Effectiveness (SE) = 20log 10(E1 / E2), where E1 is the unshielded field strength and E2 is the field strength after shielding.

[0134] 4. Smoke Density Test (1) Test Equipment: Smoke Density Chamber (NBS, ASTM E662); (2) Test Procedure: Cut a 100×100 mm sheath sample and place it in the smoke density chamber. Ignite the sample (heat flux 25 kW / m 2 ), and record the smoke density (Ds) when the light transmittance drops to the lowest value.

[0135] 5. Tensile Strength Test: (1) Test Equipment: Universal Tensile Testing Machine (Instron 5567, range 50 kN, accuracy ±0.5%); (2) Test Procedure: Cut a dumbbell-shaped sheath specimen (GB / T 1040.2) with a gauge length of 25 mm; stretch it to break at a speed of 50 mm / min, record the maximum load (F), and calculate the tensile strength: σ = F / A (A is the cross-sectional area).

[0136] Table 1 Test Results Project Example 10 Example 11 Example 12 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Refractory time at 950°C (min) 110 125 127 82 113 77 64 Afterglow time (s) 12 8 7 14 12 23 35 Insulation resistance (after combustion; MΩ / km) 540 600 620 140 580 380 245 Insulation resistance degradation rate after 30 days (%) 2.2 1.4 1.0 2.7 5.8 1.8 1.5 Number of leakage points (per m) 0 0 0 0 2 1 0 Partial discharge quantity (pC) 0.6 0.4 0.4 0.4 0.5 1.8 2.2 Shielding effectiveness (dB; 1 GHz) 81 85 87 85 83 65 60 Smoke density (Ds) 121 115 108 117 120 322 380 Tensile strength (MPa) 17.3 18.9 20.8 15.1 18.5 12.0 10.5 Analysis of the data in Table 1: 1. Fire Resistance Performance: Examples 10 - 12: The fire resistance time gradually increases (110 → 127 min), mainly due to the higher mixing pressure (0.6 MPa) and optimized chain extender ratio in Example 12, which enhance the compactness of the carbon layer; while Comparative Example 1 (without nano-montmorillonite): The fire resistance time decreases by 34%. Nano-montmorillonite improves the strength of the ceramic layer through the intercalation effect. Without it, the carbon layer is prone to cracking. Comparative Example 3 (ordinary EVA): The fire resistance time is only 77 min. The absence of the intumescent flame retardant system results in the inability to form a heat-insulating carbon layer.

[0137] 2. Waterproof Performance: Examples 10 - 12: The resistance drop rate ≤ 2.2%. The microcapsule water-absorbing resin swells and fills at the cracks, preventing water penetration; Comparative Example 2 (ordinary water-absorbing resin): There are 2 leakage points per meter, and the resistance drop rate is 5.8%. The unencapsulated resin cannot dynamically repair the gap of the aluminum-plastic tape.

[0138] 3. Leakage Protection and Electromagnetic Shielding: Examples 11 - 12: The shielding effectiveness is 85 - 87 dB. The optimized copper tape winding tension (2.5 N / mm 2 ) and coverage rate (88%) reduce electromagnetic leakage; Comparative Examples 3 - 4: The shielding effectiveness drops significantly. The absence of flame retardant EVA / PVC causes the sheath material to be unable to suppress electromagnetic interference.

[0139] 4. Environmental protection and mechanical properties: Example 12: Smoke density is 108, tensile strength is 20.8 MPa. Thanks to the synergistic smoke suppression of the expanded carbon layer of IFR-EVA and zinc borate; Comparative Example 3 (ordinary EVA): Smoke density is 322. The absence of a flame retardant leads to a large amount of smoke release; Comparative Example 4 (ordinary PVC): Tensile strength is 10.5 MPa. Unmodified PVC is brittle and has poor mechanical properties.

[0140] It should be noted that in this article, terms such as "including, containing" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or elements inherent to such a process, method, article or device.

[0141] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fireproof, waterproof and leakage-proof electric wire and cable, characterized in that: The cable comprises, from inside to outside, a conductor, a double-layer insulation layer, a waterproof layer, a shielding layer and a double-layer outer sheath; The inner layer of the double-layer insulation layer is ceramic silicone rubber; The outer layer of the double-layer insulation layer is cross-linked polyethylene; The waterproof layer contains glue injection; The materials for injection are microcapsule water-absorbing resin and silane coupling agent KH-550; The inner layer of the outer protective layer is phosphorus-nitrogen expanded flame-retardant EVA; The outer layer of the outer sheath is flame retardant polyvinyl chloride.

2. A fireproof, waterproof and leakage-proof electric wire and cable according to claim 1, characterized in that: The ceramic silicone rubber layer is composed of the following raw materials in parts by mass: 100 parts of methyl vinyl silicone rubber; 60 parts of aluminum hydroxide; 8 parts of nano-montmorillonite; 0.5 parts of platinum catalyst; and 2 parts of hydrogen-containing silicone oil crosslinking agent.

3. The fireproof, waterproof and leakage-proof electric wire and cable according to claim 1, characterized in that: The microcapsule water-absorbing resin is prepared by the following steps: dissolving sodium acrylate-acrylamide copolymer in deionized water to obtain a water phase; adding Span-80 to cyclohexane and stirring until transparent to obtain an oil phase; dropping the water phase into the oil phase, shearing and emulsifying to form a W / O type emulsion, adding a polyurethane prepolymer thereto, stirring for 30 minutes, adding 1,4-butanediol thereto, heating to 55-60° C., reacting for 4-5 hours, adding glacial acetic acid thereto, centrifuging, collecting microcapsules, washing, drying and sieving the microcapsules, and obtaining the microcapsule water-absorbing resin.

4. The fireproof, waterproof and leakage-proof electric wire and cable according to claim 3, characterized in that: The dosage ratio of the sodium acrylate-acrylamide copolymer, deionized water, cyclohexane, Span-80, polyurethane prepolymer, 1,4-butanediol and glacial acetic acid is 10g:100mL:300mL:3-4g:20g:1-2g:0.5-1mL.

5. The fireproof, waterproof and leakage-proof electric wire and cable according to claim 1, characterized in that: The preparation process of the phosphorus-nitrogen intumescent flame-retardant EVA is as follows: ammonium polyphosphate, pentaerythritol, melamine and nano-silicon dioxide are premixed, and KH-570 is added at the same time. After mixing, a premixed flame retardant is obtained, and then the EVA base material is added to an internal mixer and the temperature is raised to 90-95° C., and constant temperature melt-mixed for 3 minutes. After the completion, the premixed flame retardant is added to the internal mixer, and mixed for 8-10 minutes. After the completion, the material is discharged, and then granulated by twin-screw extrusion, and then cooled to obtain the phosphorus-nitrogen intumescent flame-retardant EVA.

6. The fireproof, waterproof and leakage-proof electric wire and cable according to claim 5, characterized in that: The weight parts of the raw materials in the phosphorus-nitrogen expanded flame-retardant EVA are as follows: 100 parts of EVA base material, 25-30 parts of ammonium polyphosphate, 15-20 parts of pentaerythritol, 10 parts of melamine, 5 parts of nano-silicon dioxide, and 1.5 parts of silane coupling agent KH-570.

7. The fireproof, waterproof and leakage-proof electric wire and cable according to claim 1, characterized in that: The preparation process of the flame-retardant polyvinyl chloride is as follows: zinc borate powder and titanate coupling agent are mixed and added into anhydrous ethanol, and modified zinc borate is obtained after ultrasonic dispersion, drying and sieving; PVC resin and dioctyl phthalate are heated to 100° C. and mixed for 5 minutes, and calcium stearate, antimony trioxide and modified zinc borate are added thereto in sequence, and mixed at 110° C. for 10 minutes, and then the mixture is cooled and discharged to obtain a mixture, and the mixture is plasticized, thinned, molded and cooled to obtain the flame-retardant polyvinyl chloride.

8. The fireproof, waterproof and leakage-proof electric wire and cable according to claim 7, characterized in that: The mass parts of the raw materials in the flame retardant polyvinyl chloride are as follows: 100 parts of PVC resin, 15 parts of zinc borate, 3-4 parts of antimony trioxide, 30 parts of dioctyl phthalate, 2-3 parts of calcium stearate, and 0.5-1 part of titanate coupling agent NDZ-201.

9. A production process for fireproof, waterproof and leakage-proof electric wire and cable according to any one of claims 1 to 8, characterized in that: The process includes: S1, twisting and cleaning the tinned copper monofilaments, spraying graphene slurry, and then drying and curing to obtain a conductor; S2, co-extrude a double-layer insulation layer on the surface of the conductor, the inner layer is a ceramic silicone rubber layer, and the outer layer is a cross-linked polyethylene. After the co-extrusion is completed, cross-linking and cooling are performed to obtain an insulated wire core; S3, longitudinally wrapping the aluminum-plastic tape on the outer peripheral side of the insulating core to obtain a longitudinally wrapped insulating core, and then injecting glue into the gap between the aluminum-plastic tapes of the longitudinally wrapped insulating core through an annular glue injection head to obtain a glue-injected core, and extruding a high-density polyethylene inner sheath layer on the outer side of the glue-injected core to form a waterproof layer to obtain a waterproof core; S4, braiding copper wires, wrapping copper tapes around the outer periphery of the waterproof wire core, and welding to form a shielding layer to obtain a shielded wire core; S5. Co-extrude a double outer sheath on the surface of the shielded wire core, the inner layer is phosphorus-nitrogen expanded flame-retardant EVA, and the outer layer is flame-retardant polyvinyl chloride. After co-extrusion, it is cooled to obtain a fire-proof, waterproof and leakage-proof wire and cable.

10. The production process of a fireproof, waterproof and leakage-proof electric wire and cable according to claim 9, characterized in that: The graphene slurry described in S1 is an aqueous dispersion with a graphene content of 5 wt%.