Environment-friendly anti-interference marine cable and preparation method thereof

Abstract

The application discloses an environmentally-friendly anti-interference marine cable and a preparation method thereof, and relates to the technical field of power cables. The aldehyde group of 4-mercapto benzaldehyde is subjected to condensation reaction with the amino group of 2-isopropenyl aniline to generate an unsaturated antioxidant monomer; the carboxyl group of 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid is subjected to esterification reaction with the hydroxyl group of 9-octadecene-1-ol to generate a hydrophobic modified hindered phenol monomer; then, the mercapto group of the unsaturated antioxidant monomer is subjected to click reaction with the double bond of the hydrophobic modified hindered phenol monomer to generate an antioxidant stabilizer, so that the synergistic antioxidant effect is achieved, and the hydrophobic structure makes the surface of the insulating layer hydrophobic, so that the performance decline caused by the penetration of seawater salt mist during use is prevented; finally, the antioxidant stabilizer, a crosslinking agent, a flame retardant, polyethylene and a heat-conducting filler are combined to melt and extrude an insulating layer composite conductor, a filling layer, a shielding layer and a protective layer to prepare the cable, so that the high insulation and anti-interference effects are achieved.

Description

Technical Field

[0001] This invention relates to the field of power cable technology, specifically to a marine environmentally friendly anti-interference cable and its preparation method. Background Technology

[0002] With the rapid development of the shipping industry and the increasing electrification of ships, traditional cables can no longer meet the stringent application requirements. Although some cables are designed to balance safety and functionality, their practical application still faces multiple challenges. First, long-term exposure to high humidity, salt spray corrosion, and severe vibration environments can easily cause materials to age and crack, leading to moisture penetration and a decline in insulation performance. Second, in complex electromagnetic field environments, the shielding effectiveness of some products decreases over time, resulting in signal crosstalk. Third, the materials used to manufacture cables can cause some environmental pollution during subsequent use. These problems not only shorten the service life of cables but may also pose safety hazards, requiring systematic solutions through material modification and structural optimization.

[0003] By modifying the materials used to prepare the insulation layer to enhance its durability, on the one hand, a dense water-repellent film is formed on the surface of the insulation layer through hydrophobic modification treatment, which significantly reduces the water absorption rate and prevents the penetration of seawater salt spray during use. This avoids the increased dielectric loss and breakdown risk caused by seawater immersion or high humidity, and provides long-term protection for the internal conductor. On the other hand, multiple antioxidant mechanisms inhibit oxidation reactions and delay aging and cracking caused by ultraviolet rays and heat and oxygen, thereby improving the stability and aging resistance of the cable and enhancing the safety of the cable in use. Summary of the Invention

[0004] The purpose of this invention is to provide a marine environmentally friendly anti-interference cable and its preparation method to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a marine environmentally friendly anti-interference cable, comprising, from the inside out: a conductor, a filling layer, an insulation layer, a shielding layer, and a protective layer; the insulation layer is composed of the following raw materials in parts by weight: 2-4 parts of self-made antioxidant stabilizer, 3-4 parts of crosslinking agent, 10-12 parts of flame retardant, 105 parts of polyethylene, and 8-10 parts of thermally conductive filler; the self-made antioxidant stabilizer is prepared by reacting unsaturated antioxidant monomers and hydrophobically modified hindered phenolic monomers at a mass ratio of 1:1.9-2.1; the unsaturated antioxidant monomers are prepared by reacting 4-mercaptobenzaldehyde and 2-isopropenylphenylaniline at a mass ratio of 1:1-1.1, and the hydrophobically modified hindered phenolic monomers are prepared by reacting 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and 9-octadecen-1-ol at a mass ratio of 1:1-1.08.

[0006] Furthermore, the conductor consists of seven aluminum alloy wires.

[0007] Furthermore, the filling layer is composed of dust-free rock wool rope.

[0008] Furthermore, the shielding layer is made by braiding copper strips over the insulation layer.

[0009] Furthermore, the protective layer is made of nickel-plated steel strip wrapped around it.

[0010] Furthermore, the crosslinking agent is trimethylolpropane trimethacrylate.

[0011] Furthermore, the flame retardant is aluminum hydroxide.

[0012] Furthermore, the polyethylene is prepared by mixing low-density polyethylene and linear low-density polyethylene at a mass ratio of 2:1.

[0013] Furthermore, the thermally conductive filler includes hexagonal boron nitride and silica.

[0014] Furthermore, the marine environmentally friendly anti-interference cable includes the following preparation steps: (1) Under nitrogen protection, 4-mercaptobenzaldehyde, 2-isopropenylphenylaniline and anhydrous ethanol were mixed in a mass ratio of 1:1-1.1:10, and acetic acid with a mass of 0.01-0.03 times that of 4-mercaptobenzaldehyde was added. The mixture was stirred at 15-25℃ for 2-3 hours, then cooled to 0-5℃, filtered, washed and dried to obtain an unsaturated antioxidant monomer. (2) Under nitrogen protection, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 9-octadecen-1-ol and dimethyl sulfoxide solution were mixed at a mass ratio of 1:1-1.08:10, and tetrabutyl titanate was added at a mass ratio of 0.02-0.04 times that of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid. The mixture was stirred at 150-160℃ for 3-4 hours. After filtration, washing and drying, hydrophobic modified hindered phenol monomer was obtained. (3) Under nitrogen protection, unsaturated antioxidant monomers, hydrophobically modified hindered phenol monomers, and toluene were mixed at a mass ratio of 1:1.9-2.1:12. Azobisisobutyronitrile was added at a mass ratio of 0.006-0.01 times that of the unsaturated antioxidant monomers. The mixture was stirred at 75-85℃ for 3.5-4.5 h. After filtration, washing, and drying, the self-made antioxidant stabilizer was obtained. (4) Seven aluminum alloy wires are used to form a conductor, and the gaps between the conductors are filled with dust-free rock wool rope to make a cable core; 3-4 parts of trimethylolpropane trimethacrylate, 70 parts of low-density polyethylene, 35 parts of linear low-density polyethylene, 10-12 parts of aluminum hydroxide, 8-10 parts of modified thermally conductive filler, and 2-4 parts of self-made antioxidant stabilizer are mixed and pre-crosslinked at 115-125℃ for 15-25 minutes, and then extruded and coated on the conductor for electron beam irradiation crosslinking. The irradiation energy is 1.5MeV and the dose is 120-160kGy. After irradiation, an insulation layer with a thickness of 0.8-1.4mm is obtained. Copper tape is braided and wrapped around the insulation layer to make a shielding layer with a thickness of 0.6-1.2mm. Nickel-plated steel tape is wrapped around the shielding layer to make a protective layer with a thickness of 3-4mm. Then, crosslinked polyethylene insulated power cable is obtained.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention prepares a marine anti-interference cable using a conductor, a filler layer, an insulation layer, a shielding layer, and a protective layer. The insulation layer is made by melt extrusion of a thermally conductive filler treated with a self-made antioxidant stabilizer, crosslinking agent, flame retardant, and polyethylene combined with a coupling agent. Polyethylene has good insulation properties, and the combination with the thermally conductive filler can improve the thermal conductivity of the insulation layer and extend its service life. At the same time, the coupling agent can promote the dispersion of the thermally conductive filler and enhance the interfacial bonding ability with polyethylene, further improving the insulation performance. The resulting cable has high insulation and anti-interference effects.

[0016] The self-made antioxidant stabilizer utilizes the condensation reaction between the aldehyde group of 4-mercaptobenzaldehyde and the amino group of 2-isopropenylphenylaniline to generate an unsaturated antioxidant monomer. The presence of the thiol group enhances the subsequent reactivity of the monomer, and the double bond can participate in subsequent cross-linking. The carboxyl group of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid undergoes an esterification reaction with the hydroxyl group of 9-octadecen-1-ol to generate a hydrophobically modified hindered phenol monomer. The introduction of the long-chain alkyl group makes the insulation surface hydrophobic, acting as a second barrier for the cable to prevent the penetration of seawater salt spray during use and avoid hydrolysis leading to performance degradation. The thiol group of the unsaturated antioxidant monomer undergoes a click reaction with the double bond of the hydrophobically modified hindered phenol monomer to generate an antioxidant stabilizer. The introduction of the hydrophobically modified hindered phenol further enhances the free radical scavenging ability of the antioxidant stabilizer, achieving a synergistic antioxidant effect. This multidimensionally improves the stability and aging resistance of the insulation layer, enhancing the safety of the cable in use. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] To more clearly illustrate the method provided by the present invention, the following embodiments are provided in detail. The following embodiments describe a method for testing various indicators of a marine environmentally friendly anti-interference cable: Oxidation rate: Referring to HB 5258-2014 standard, the sample was placed in an environment of 550℃ and 1 atm high-purity oxygen for 24h, and its mass increment per unit area was weighed at room temperature to calculate its oxidation rate. Fire and water resistance performance: The test shall be conducted in accordance with BS6387 "Fire resistance test method for maintaining the integrity of the cable under flame conditions". The sample shall be placed at 650°C and subjected to fire impact for 15 minutes, and then subjected to water spray for 15 minutes without breaking down. Dielectric constant: The relative dielectric constant of the sample was measured using a Concept80 broadband dielectric and impedance spectrometer. The sample was placed at 20℃ and 0.1Hz.

[0019] Example 1; (1) By mass, under nitrogen protection, 10 parts of 4-mercaptobenzaldehyde, 10 parts of 2-isopropenylphenylaniline and 100 parts of anhydrous ethanol were mixed, 0.1 parts of acetic acid were added, and the mixture was stirred at 100 rpm for 2 h at 15 °C. The mixture was cooled to 0 °C in an ice bath, and the solid was filtered and washed twice with saturated sodium bicarbonate solution and deionized water, and dried at 40 °C for 12 h to obtain an unsaturated antioxidant monomer; (2) By mass, under nitrogen protection, 10 parts of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 10 parts of 9-octadecen-1-ol, and 100 parts of dimethyl sulfoxide solution were mixed, and 0.2 parts of tetrabutyl titanate were added. The mixture was stirred at 125 rpm for 3 h at 150 °C. After cooling to room temperature, the solid was filtered and washed twice with methanol. The solid was dried at 50 °C for 10 h to obtain the hydrophobically modified hindered phenol monomer. (3) By mass fraction, under nitrogen protection, 10 parts of unsaturated antioxidant monomer, 19 parts of hydrophobically modified hindered phenol monomer, and 120 parts of anhydrous toluene were mixed, and 0.06 parts of azobisisobutyronitrile were added. The mixture was stirred at 80 rpm for 3.5 h at 75 °C. After cooling to room temperature, the solid was filtered and washed twice with acetone. The solid was dried at 60 °C for 9 h to obtain the self-made antioxidant stabilizer. (4) According to the mass fraction, 2 parts of KH570, 80 parts of anhydrous ethanol and 80 parts of deionized water are mixed and stirred at 40℃ and 100rpm for 45min. 1.5 parts of hexagonal boron nitride and 1.5 parts of silica are added to the solution and stirred continuously at 200rpm for 3h. After filtration, the solid is washed 3 times with acetone and dried at 90℃ for 8h to obtain the modified thermally conductive filler. (5) Seven aluminum alloy wires with a diameter of 4.4 mm are twisted and pressed together to form a conductor. The gaps between the conductors are filled with dust-free rock wool rope to make a cable core. 3 parts of trimethylolpropane trimethacrylate, 70 parts of low-density polyethylene, 35 parts of linear low-density polyethylene, 10 parts of aluminum hydroxide, 8 parts of modified thermally conductive filler, and 2 parts of self-made antioxidant stabilizer are mixed and pre-crosslinked at a temperature of 115℃ and a rotation speed of 60 rpm for 15 min. Then, the mixture is extruded and coated onto the conductor for electron beam irradiation crosslinking. The irradiation energy is 1.5 MeV and the dose is 120 kGy. After irradiation, an insulation layer with a thickness of 0.8 mm is obtained. Copper tape is braided and wrapped around the insulation layer to obtain a shielding layer with a thickness of 0.6 mm. Nickel-plated steel tape is wrapped around the shielding layer to obtain a protective layer with a thickness of 3 mm. Then, a crosslinked polyethylene insulated power cable is obtained.

[0020] Example 2; (1) By mass, under nitrogen protection, 10 parts of 4-mercaptobenzaldehyde, 10.5 parts of 2-isopropenylphenylaniline and 100 parts of anhydrous ethanol were mixed, 0.2 parts of acetic acid were added, and the mixture was stirred at 100 rpm for 2.5 h at 20 °C. The mixture was cooled to 2 °C in an ice bath, and the solid was filtered and washed twice with saturated sodium bicarbonate solution and deionized water, and dried at 40 °C for 12 h to obtain an unsaturated antioxidant monomer; (2) By mass, under nitrogen protection, 10 parts of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 10.4 parts of 9-octadecen-1-ol, and 100 parts of dimethyl sulfoxide solution were mixed, and 0.3 parts of tetrabutyl titanate were added. The mixture was stirred at 125 rpm at 155 °C for 3.5 h. After cooling to room temperature, the solid was filtered and washed twice with methanol. The solid was dried at 50 °C for 10 h to obtain the hydrophobically modified hindered phenol monomer. (3) By mass fraction, under nitrogen protection, 10 parts of unsaturated antioxidant monomer, 20 parts of hydrophobically modified hindered phenol monomer, and 120 parts of anhydrous toluene were mixed, and 0.08 parts of azobisisobutyronitrile were added. The mixture was stirred at 80 rpm for 4 h at 80 °C. After cooling to room temperature, the solid was filtered and washed twice with acetone. The solid was dried at 60 °C for 9 h to obtain the self-made antioxidant stabilizer. (4) According to the mass fraction, 2 parts of KH570, 80 parts of anhydrous ethanol and 80 parts of deionized water are mixed and stirred at 40℃ and 100rpm for 45min. 1.5 parts of hexagonal boron nitride and 1.5 parts of silica are added to the solution and stirred continuously at 200rpm for 3h. After filtration, the solid is washed 3 times with acetone and dried at 90℃ for 8h to obtain the modified thermally conductive filler. (5) Seven aluminum alloy wires with a diameter of 4.4 mm are twisted and pressed together to form a conductor. The gaps between the conductors are filled with dust-free rock wool rope to make a cable core. 3.5 parts of trimethylolpropane trimethacrylate, 70 parts of low-density polyethylene, 35 parts of linear low-density polyethylene, 11 parts of aluminum hydroxide, 9 parts of modified thermally conductive filler, and 3 parts of self-made antioxidant stabilizer are mixed and pre-crosslinked at a temperature of 120℃ and a speed of 70 rpm for 20 min. Then, the mixture is extruded and coated onto the conductor for electron beam irradiation crosslinking. The irradiation energy is 1.5 MeV and the dose is 140 kGy. After irradiation, an insulation layer with a thickness of 1.1 mm is obtained. Copper tape is braided and wrapped around the insulation layer to make a shielding layer with a thickness of 0.9 mm. Nickel-plated steel tape is wrapped around the shielding layer to make a protective layer with a thickness of 3.5 mm. Then, a crosslinked polyethylene insulated power cable is obtained.

[0021] Example 3; (1) By mass, under nitrogen protection, 10 parts of 4-mercaptobenzaldehyde, 11 parts of 2-isopropenylphenylaniline and 100 parts of anhydrous ethanol were mixed, 0.3 parts of acetic acid were added, and the mixture was stirred at 100 rpm for 3 h at 25 °C. The mixture was cooled to 5 °C in an ice bath, and the solid was filtered and washed twice with saturated sodium bicarbonate solution and deionized water, and dried at 40 °C for 12 h to obtain an unsaturated antioxidant monomer; (2) By mass, under nitrogen protection, 10 parts of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 10.8 parts of 9-octadecen-1-ol, and 100 parts of dimethyl sulfoxide solution were mixed, and 0.4 parts of tetrabutyl titanate were added. The mixture was stirred at 125 rpm for 4 h at 160 °C. After cooling to room temperature, the solid was filtered and washed twice with methanol. The solid was dried at 50 °C for 10 h to obtain the hydrophobically modified hindered phenol monomer. (3) By mass, under nitrogen protection, 10 parts of unsaturated antioxidant monomer, 21 parts of hydrophobically modified hindered phenol monomer, and 120 parts of anhydrous toluene were mixed, and 0.1 parts of azobisisobutyronitrile were added. The mixture was stirred at 80 rpm for 4.5 h at 85 °C. After cooling to room temperature, the solid was filtered and washed twice with acetone. The solid was dried at 60 °C for 9 h to obtain the self-made antioxidant stabilizer. (4) According to the mass fraction, 2 parts of KH570, 80 parts of anhydrous ethanol and 80 parts of deionized water are mixed and stirred at 40℃ and 100rpm for 45min. 1.5 parts of hexagonal boron nitride and 1.5 parts of silica are added to the solution and stirred continuously at 200rpm for 3h. After filtration, the solid is washed 3 times with acetone and dried at 90℃ for 8h to obtain the modified thermally conductive filler. (5) Seven aluminum alloy wires with a diameter of 4.4 mm are twisted and pressed together to form a conductor. The gaps between the conductors are filled with dust-free rock wool rope to make a cable core. 4 parts of trimethylolpropane trimethacrylate, 70 parts of low-density polyethylene, 35 parts of linear low-density polyethylene, 12 parts of aluminum hydroxide, 10 parts of modified thermally conductive filler, and 4 parts of self-made antioxidant stabilizer are mixed and pre-crosslinked at a temperature of 120℃ and a speed of 70 rpm for 20 min. Then, the mixture is extruded and coated onto the conductor for electron beam irradiation crosslinking. The irradiation energy is 1.5 MeV and the dose is 160 kGy. After irradiation, an insulation layer with a thickness of 1.4 mm is obtained. Copper tape is braided and wrapped around the insulation layer to make a shielding layer with a thickness of 1.2 mm. Nickel-plated steel tape is wrapped around the shielding layer to make a protective layer with a thickness of 4 mm. Then, a crosslinked polyethylene insulated power cable is obtained.

[0022] Comparative Example 1; The difference between Comparative Example 1 and Example 2 is that step (1) is different. Step (1) is changed to: under nitrogen protection, 10 parts benzaldehyde, 10 parts aniline and 100 parts anhydrous ethanol are mixed by mass, 0.2 parts acetic acid is added, and the mixture is stirred at 100 rpm for 2.5 h at 20 °C. After cooling to 2 °C in an ice bath, the solid is filtered and washed twice with saturated sodium bicarbonate solution and deionized water, and dried at 40 °C for 12 h to obtain the antioxidant monomer; Step (3) is changed to: under nitrogen protection, 10 parts antioxidant monomer, 25 parts hydrophobically modified hindered phenol monomer and 120 parts anhydrous toluene are mixed by mass, 0.08 parts azobisisobutyronitrile is added, and the mixture is stirred at 80 rpm for 4 h at 80 °C. After cooling to room temperature, the solid is filtered and washed twice with acetone, and dried at 60 °C for 9 h to obtain the self-made antioxidant stabilizer; The remaining steps are the same as in Example 2.

[0023] Comparative Example 2; The difference between Comparative Example 2 and Example 2 is that step (1) is omitted, and step (3) is changed to: by mass parts, under nitrogen protection, 20 parts of hydrophobically modified hindered phenol monomer and 120 parts of anhydrous toluene are mixed, 0.08 parts of azobisisobutyronitrile are added, and the mixture is stirred at 80°C and 80 rpm for 4 hours. After cooling to room temperature, the solid is filtered and washed twice with acetone, and dried at 60°C for 9 hours to obtain the self-made antioxidant stabilizer; the remaining steps are the same as in Example 2.

[0024] Comparative Example 3; The difference between Comparative Example 3 and Example 2 is that step (2) is different. Step (2) is changed to: under nitrogen protection, 10 parts of 2,2-dimethylpropionic acid, 8 parts of n-butanol and 100 parts of dimethyl sulfoxide solution are mixed, 0.3 parts of tetrabutyl titanate are added, and the mixture is stirred at 125 rpm at 155°C for 3.5 h. After cooling to room temperature, the solid is filtered and washed twice with methanol and dried at 50°C for 10 h to obtain the hindered phenol monomer. Step (3) is changed to: under nitrogen protection, 9 parts of unsaturated antioxidant monomer, 6 parts of hindered phenol monomer and 60 parts of anhydrous toluene are mixed, 0.08 parts of azobisisobutyronitrile are added, and the mixture is stirred at 80 rpm at 80°C for 4 h. After cooling to room temperature, the solid is filtered and washed twice with acetone and dried at 60°C for 9 h to obtain the self-made antioxidant stabilizer. The remaining steps are the same as in Example 2.

[0025] Comparative Example 4; The difference between Comparative Example 4 and Example 2 is that step (3) is omitted, and step (5) is changed to: using seven aluminum alloy wires with a diameter of 4.4 mm to twist and press together to form a conductor, and filling the gaps between the conductors with dust-free rock wool rope to obtain a cable core; mixing 3.5 parts of trimethylolpropane trimethacrylate, 70 parts of low-density polyethylene, 35 parts of linear low-density polyethylene, 11 parts of aluminum hydroxide, 4.5 parts of modified hexagonal boron nitride, and 4.5 parts of modified silica, and performing a 20m process at a temperature of 120℃ and a rotation speed of 70 rpm. In the melt pre-crosslinking process, 1 part of unsaturated antioxidant monomer and 2 parts of hydrophobically modified hindered phenol monomer are added and mixed for 10 min. Then, the mixture is extruded and coated onto the conductor for electron beam irradiation crosslinking. The irradiation energy is 1.5 MeV and the dose is 140 kGy. After irradiation, an insulation layer with a thickness of 1.1 mm is obtained. Copper tape is braided and wrapped around the insulation layer to obtain a shielding layer with a thickness of 0.9 mm. Nickel-plated steel tape is wrapped around the shielding layer to obtain a protective layer with a thickness of 3.5 mm. Then, a crosslinked polyethylene insulated power cable is obtained. The remaining steps are the same as in Example 2.

[0026] Comparative Example 5; The difference between Comparative Example 5 and Example 2 is that step (5) is different. Step (5) is changed to: using seven aluminum alloy wires with a diameter of 4.4 mm to twist and press together to form a conductor, and filling the gaps between the conductors with dust-free rock wool rope to obtain a cable core; mixing 3.5 parts of trimethylolpropane trimethacrylate, 70 parts of low-density polyethylene, 35 parts of linear low-density polyethylene, 11 parts of aluminum hydroxide, and 9 parts of modified thermally conductive filler, and performing melt pre-crosslinking at a temperature of 120°C and a rotation speed of 70 rpm for 20 min, and then extruding and coating it on the conductor for electron beam irradiation crosslinking, with an irradiation energy of 1.5 MeV and a dose of 140 kGy. After irradiation, an insulation layer with a thickness of 1.1 mm is obtained. Copper tape is braided and wrapped around the insulation layer to obtain a shielding layer with a thickness of 0.9 mm. Nickel-plated steel tape is wrapped around the shielding layer to obtain a protective layer with a thickness of 3.5 mm. Then, a crosslinked polyethylene insulated power cable is obtained; the remaining steps are the same as in Example 2.

[0027] Example of effect Table 1 below shows the performance analysis results of a marine environmentally friendly anti-interference cable using Embodiments 1 to 3 and Comparative Examples 1 to 5 of the present invention.

[0028] Table 1

[0029] A comparison of experimental data on fire resistance and water resistance between the examples and comparative examples reveals that the present invention utilizes the esterification reaction of the carboxyl group of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with the hydroxyl group of 9-octadecen-1-ol to generate a hydrophobically modified hindered phenolic monomer with an octadecyl hydrophobic tail chain. The introduction of the long-chain alkyl group makes the surface of the insulation layer hydrophobic, serving as a second barrier for the cable and preventing the penetration of seawater salt spray during use. A comparison of experimental data on oxidation rates between the examples and comparative examples reveals that the present invention uses the condensation reaction of the aldehyde group of 4-mercaptobenzaldehyde with the amino group of 2-isopropenylphenylaniline to generate an unsaturated antioxidant monomer, forming a conjugated system containing an imine group (C=N). The conjugated double bond can act as an electron transfer channel to quickly capture free radicals, and the thiol group on the aromatic ring can enhance the activity of the ortho-hydrogen atom, promoting hydrogen supply capacity. The subsequent reaction is promoted by the click reaction between the thiol group of the unsaturated antioxidant monomer and the double bond of the hydrophobically modified hindered phenol monomer to generate an antioxidant stabilizer. The introduction of hydrophobically modified hindered phenol further enhances the free radical scavenging ability of the antioxidant stabilizer, prevents the growth of free radical chains, and achieves an antioxidant effect in synergy with the conjugated structure. The experimental data of dielectric constant of the examples and comparative examples show that the present invention obtains the insulation layer by melt extrusion of thermally conductive filler treated with self-made antioxidant stabilizer, crosslinking agent, flame retardant, polyethylene and coupling agent. The full dispersion of thermally conductive filler can improve the thermal conductivity and interfacial bonding ability of the insulation layer, improve the service life of the insulation layer, and further improve the insulation performance. The presence of crosslinked structure is conducive to fixing space charge, inhibiting oxidation by-products, preventing the increase of dielectric constant, and thus comprehensively improving the performance of crosslinked polyethylene insulated power cable.

[0030] 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 its spirit or essential characteristics. 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, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A marine-grade environmentally friendly anti-interference cable, characterized in that, From the inside out, they are: conductor, filling layer, insulating layer, shielding layer, and protective layer; The insulating layer is composed of the following raw materials in parts by weight: 2-4 parts self-made antioxidant stabilizer, 3-4 parts crosslinking agent, 10-12 parts flame retardant, 105 parts polyethylene, and 8-10 parts thermally conductive filler. The self-made antioxidant stabilizer was prepared by reacting unsaturated antioxidant monomers and hydrophobically modified hindered phenolic monomers at a mass ratio of 1:1.9-2.

1. The unsaturated antioxidant monomer is prepared by reacting 4-mercaptobenzaldehyde and 2-isopropenylphenylaniline in a mass ratio of 1:1-1.1, and the hydrophobically modified hindered phenol monomer is prepared by reacting 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and 9-octadecen-1-ol in a mass ratio of 1:1-1.

08.

2. The marine environmentally friendly anti-interference cable according to claim 1, characterized in that, The conductor consists of seven aluminum alloy wires.

3. The marine environmentally friendly anti-interference cable according to claim 1, characterized in that, The filling layer consists of dust-free rock wool rope.

4. The marine environmentally friendly anti-interference cable according to claim 1, characterized in that, The shielding layer is made by braiding copper strips over the insulation layer.

5. The marine environmentally friendly anti-interference cable according to claim 1, characterized in that, The protective layer is made of nickel-plated steel strip wrapped around it.

6. The marine environmentally friendly anti-interference cable according to claim 1, characterized in that, The crosslinking agent is trimethylolpropane trimethacrylate.

7. The marine environmentally friendly anti-interference cable according to claim 1, characterized in that, The flame retardant is aluminum hydroxide.

8. The marine environmentally friendly anti-interference cable according to claim 1, characterized in that, The polyethylene is prepared by mixing low-density polyethylene and linear low-density polyethylene at a mass ratio of 2:

1.

9. A marine environmentally friendly anti-interference cable according to claim 1, characterized in that, The thermally conductive filler includes hexagonal boron nitride and silica.

10. A marine environmentally friendly anti-interference cable according to claim 1, characterized in that, The preparation steps include the following: (1) Under nitrogen protection, 4-mercaptobenzaldehyde, 2-isopropenylphenylaniline and anhydrous ethanol were mixed in a mass ratio of 1:1-1.1:10, and acetic acid with a mass of 0.01-0.03 times that of 4-mercaptobenzaldehyde was added. The mixture was stirred at 15-25℃ for 2-3 hours, then cooled to 0-5℃, filtered, washed and dried to obtain an unsaturated antioxidant monomer. (2) Under nitrogen protection, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 9-octadecen-1-ol and dimethyl sulfoxide solution were mixed at a mass ratio of 1:1-1.08:10, and tetrabutyl titanate was added at a mass ratio of 0.02-0.04 times that of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid. The mixture was stirred at 150-160℃ for 3-4 hours. After filtration, washing and drying, hydrophobic modified hindered phenol monomer was obtained. (3) Under nitrogen protection, unsaturated antioxidant monomers, hydrophobically modified hindered phenol monomers, and toluene were mixed at a mass ratio of 1:1.9-2.1:

12. Azobisisobutyronitrile was added at a mass ratio of 0.006-0.01 times that of the unsaturated antioxidant monomers. The mixture was stirred at 75-85℃ for 3.5-4.5 h. After filtration, washing, and drying, the self-made antioxidant stabilizer was obtained. (4) Seven aluminum alloy wires are used to form a conductor, and the gaps between the conductors are filled with dust-free rock wool rope to make a cable core; 3-4 parts of trimethylolpropane trimethacrylate, 70 parts of low-density polyethylene, 35 parts of linear low-density polyethylene, 10-12 parts of aluminum hydroxide, 8-10 parts of modified thermally conductive filler, and 2-4 parts of self-made antioxidant stabilizer are mixed and pre-crosslinked at 115-125℃ for 15-25 minutes, and then extruded and coated on the conductor for electron beam irradiation crosslinking. The irradiation energy is 1.5MeV and the dose is 120-160kGy. After irradiation, an insulation layer with a thickness of 0.8-1.4mm is obtained. Copper tape is braided and wrapped around the insulation layer to make a shielding layer with a thickness of 0.6-1.2mm. Nickel-plated steel tape is wrapped around the shielding layer to make a protective layer with a thickness of 3-4mm. Then, crosslinked polyethylene insulated power cable is obtained.

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