Anti-corrosion anti-aging cable

Abstract

The invention discloses an anti-corrosion and anti-aging cable which sequentially comprises a cable core, a water-blocking tape, a modified PVC insulating layer, a repairing layer, an armor layer and a polyurethane outer sheath from inside to outside. The preparation process of the modified PVC insulating layer comprises the steps of PVC swelling, grafting reaction, hydrolytic condensation and extrusion. According to the invention, the high-hydrophobicity insulation layer is constructed through swelling-assisted silane grafting PVC, the intelligent repair layer of BTA intercalation hydrotalcite and zinc powder is combined, and through collaborative design of the modified PVC insulation layer and the intelligent repair layer, triple protection of the whole life cycle of the cable is realized: the repair layer, the hydrophobic PVC insulation layer and the water-blocking tape layer; the problems of metal protection and polymer aging of the cable in a corrosive environment are solved, and the cable is especially suitable for deep and far sea power / communication engineering.

Description

Technical Field

[0001] This invention relates to the field of special anti-corrosion cable technology, and in particular to an anti-corrosion and anti-aging cable. Background Technology

[0002] With the development of offshore wind power, deep-sea exploration, and coastal power transmission, cables are exposed to harsh environments such as high salt spray, strong ultraviolet radiation, and humid heat corrosion for extended periods, facing two core challenges: 1) Corrosion of metal components: After the armor layer is damaged, electrolytes (such as seawater) invade along the cracks, causing electrochemical corrosion of copper conductors / steel wires. Traditional corrosion inhibitors (such as benzotriazole) are easily lost and become ineffective.

[0003] 2) Polymer aging: PVC insulation layers are prone to plasticizer migration and molecular chain breakage in humid / heat / UV environments, leading to a decline in insulation performance; at the same time, the release of HCl (PVC degradation products) will accelerate metal corrosion.

[0004] Existing technologies mainly employ single protection strategies, such as methods that modify the insulation layer or add a repair layer: 1) Insulation layer modification: The heat resistance of PVC can be improved by adding inorganic fillers (such as calcium carbonate), but it is difficult to achieve hydrophobicity, UV resistance and inhibition of HCl release at the same time; 2) Repair layer design: Directly mixing corrosion inhibitors with polymer matrix can lead to premature release or uneven distribution of the corrosion inhibitors, resulting in poor long-term protection.

[0005] There is an urgent need for a multi-level synergistic protection system that can block the penetration of corrosive media in the insulation layer, endow damaged areas with self-repair capabilities, and inhibit the chain reaction of polymer aging. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a corrosion-resistant and anti-aging cable.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A corrosion-resistant and anti-aging cable, comprising, from the inside out, a cable core, a water-blocking strip, a modified PVC insulation layer, a repair layer, an armor layer, and a polyurethane outer sheath; The cable core includes tensile rope, power core, control core, and optical fiber; The preparation process of the modified PVC insulation layer is as follows: 1) PVC swelling: Mix PVC granules (PVC purity ≥ 99%) and tetrahydrofuran (THF) at a weight ratio of 1:10, and swell at 50-60℃ (to avoid PVC softening and deformation) for 30-60 minutes to obtain PVC swelling material with a swelling rate of 40-45%. 2) Grafting reaction: PVC swelling material, vinyltriethoxysilane (VTES) and benzoyl peroxide (BPO) are mixed in a weight ratio of 10:12-15:0.5-1 and reacted at 70-80℃ under oxygen-free sealed conditions for 2-4 hours to obtain silane-modified PVC. 3) Hydrolysis and condensation: Silane-modified PVC, mercaptopropyltrimethoxysilane, nano-silica (particle size 20-50nm), aqueous acetic acid solution and titanate catalyst were reacted in a weight ratio of 100:5-7:7-10:15-18:0.1-0.2, with pH 4.5-5.2, at 60℃ in a sealed environment for 6-8 hours to obtain silicon crosslinked PVC. 4) Squeezing: Modified PVC granules were obtained by extruding silicone crosslinked PVC, liquid barium zinc stabilizer (SD-101 liquid barium zinc, Shandong Sancheng New Material Technology Co., Ltd., to inhibit HCl release) and trioctyl trimellitate (TOTM) in a weight ratio of 100:6-7:15-20 through a twin-screw extruder. Modified PVC granules are softened at 115-125℃ and extruded onto the water-blocking tape of the cable core to obtain a modified PVC insulation layer.

[0008] Preferably, the cable core manufacturing process is as follows: multiple power cores are first wrapped around the tensile rope and fixed by twisting to obtain a stranded core. Control cores and optical fibers are placed on the outside of both sides of the stranded core, and then fixed by wrapping with water-blocking tape to obtain a cable core with water-blocking tape.

[0009] Preferably, the tensile rope is made of Kevlar or nylon fiber, and the material and size can be selected according to cost and tensile requirements of the dragging environment; The power core consists of a copper conductor core, a cross-linked polyethylene insulation layer, and a copper tape shielding layer from the inside out. The copper conductor core is made of multiple strands of copper conductors twisted together, which improves the cable's resistance to bending. The space between the copper conductor core and the cross-linked polyethylene insulation layer is filled with heat dissipation filler, which is a mixture of paraffin wax, hydrotalcite and nano calcium carbonate in a weight ratio of 5:3-4:1-2. Hydrotalcite also has a certain water-blocking effect.

[0010] The control core includes signal wires, PVC insulation, wrapping tape, and cross-linked polyethylene inner sheath. The signal wires are covered with PVC insulation. Multiple strands of signal wires with PVC insulation are twisted together and then secured with wrapping tape, followed by extrusion of the cross-linked polyethylene inner sheath. The PVC insulation is made of high-performance insulating PVC cable material (Luoyang Weiqiang Plastics Co., Ltd.), and is available in various colors to mark different signal wires. The optical fiber consists of a core, an inner cladding, an inner coating, and an outer coating, from the inside out. The inner cladding is fluorine-doped silicon dioxide (F-SiO2), with an F doping concentration of 0.1-1 wt% (to reduce the refractive index and create optical confinement), and its diameter is 6-8 times that of the core. The inner coating is a low-modulus UV-cured acrylate resin with a modulus of 0.1-1 MPa (for soft buffering) and a thickness of 30-40 μm. The outer coating is a high-modulus UV-cured epoxy acrylate with a modulus of 1000-2000 MPa (for rigid protection) and a thickness of 25-35 μm. Preferably, the water-blocking tape is a polyester non-woven water-blocking tape (DL water-blocking tape, Jiangsu Taiyuan Cable Material Co., Ltd., mainly made of polyester non-woven fabric, adhesive, high-speed expanding polymer water-absorbing resin and other materials), which absorbs water and expands, thereby improving the sealing performance of the cable core; Preferably, the preparation process of the repair layer is as follows: Hydrotalcite is calcined at 480-520℃ for 4-6 hours and then cooled to room temperature to obtain calcined hydrotalcite powder. Subsequently, calcined hydrotalcite, benzotriazole, and water are mixed to form a suspension with a solid content of 10%. The mixture is stirred in a homogenizer at 1000-1500 r / min and 90-95℃ for 20-30 minutes. After centrifugation, the precipitate is washed with water and dried to obtain benzotriazole (BTA) intercalated hydrotalcite. Then, benzotriazole intercalated hydrotalcite, modified PVC granules, and zinc powder are mixed and softened at 125-135℃. The mixture is then extruded onto the outside of a modified PVC insulation layer with a thickness of 5-6% of the modified PVC insulation layer.

[0011] Furthermore, the weight ratio of modified PVC granules, benzotriazole, hydrotalcite, and zinc powder is 10:20-25:30-35:3-4.

[0012] Preferably, the armor layer is a single-layer shielding armor protective layer formed by multiple steel wires spirally wrapped around the repair layer; Preferably, the polyurethane outer sheath is a watertight sheath made of TPU foam (zero buoyancy PUR sheath, Shanghai Yixing Industrial Co., Ltd.).

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention first involves swelling PVC, then polymerizing vinyl silane to form long-chain silanes, followed by hydrolysis and condensation to obtain a silicon crosslinked network structure interwoven with the PVC system. The silanol groups generated after hydrolysis of mercaptopropyl silane and silane-modified PVC condense with the hydroxyl groups on the surface of nano-silica to form a Si-O-Si three-dimensional network that significantly enhances hydrophobicity, blocks the penetration path of water molecules, results in less loss during humid heat aging, and has a low rate of change in insulation resistance after aging. At the same time, the -SH groups of mercaptopropyl silane can undergo click reactions with the remaining vinyl groups and free radicals in the system, further improving the uniformity of distribution between the inorganic phase of nano-silica and the organic phase of silane-modified PVC, thereby improving the thermal stability and strength of PVC.

[0014] 2. The present invention also adds liquid barium zinc stabilizer to PVC material to capture HCl produced by PVC degradation, and in combination with the thermal stability of silicon network, further improves anti-aging performance.

[0015] 3. This invention also adds a repair layer between the steel wire armor and the modified PVC insulation layer, using BTA intercalation with hydrotalcite for controlled-release repair. When the armor layer is damaged and electrolyte enters, Cl... - With BTA - Ion exchange occurs, BTA due to Cl - The zinc powder reacts to the metal surface in response to the stimulus and forms a chelating film, blocking electrochemical corrosion. In addition, the zinc powder acts as a sacrificial anode. During the corrosion process, zinc will generate corrosion products such as zinc oxide and zinc hydroxide. These products are mostly loose or gel-like, which can fill the gaps in the armor layer and reduce the further intrusion of electrolytes, playing a "secondary sealing" role. This results in a repair layer with a certain repair capability, which further improves the corrosion resistance and sealing and waterproofing properties. 4. In summary, this invention constructs a highly hydrophobic insulation layer by grafting PVC with swelling-assisted silane, and combines it with a smart repair layer of BTA-intercalated hydrotalcite and zinc powder. Through the synergistic design of the modified PVC insulation layer and the smart repair layer, triple protection is achieved throughout the cable's life cycle: a repair layer, a hydrophobic PVC insulation layer, and a water-blocking strip layer. This solves the problems of metal protection and polymer aging in corrosive environments, and is particularly suitable for deep-sea power / communication engineering projects. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an anti-corrosion and anti-aging cable proposed in this invention.

[0017] In the diagram: Cable core 1, tensile rope 101, power core 102, copper conductor core 102A, cross-linked polyethylene (XLPE) insulation layer 102B, copper tape shielding layer 102C, heat dissipation filler 102D, control core 103, signal line 103A, PVC insulation sheath 103B, wrapping tape 103C, cross-linked polyethylene inner sheath 103D, optical fiber 104, fiber core 104A, inner sheath 104B, inner coating layer 104C, outer coating layer 104D, water-blocking tape 2, modified PVC insulation layer 3, repair layer 4, armor layer 5, polyurethane outer sheath 6. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with existing known technologies. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] I. Cable Preparation Example 1 Reference Figure 1 A corrosion-resistant and anti-aging cable, comprising, from the inside out, a cable core 1, a water-blocking strip 2, a modified PVC insulation layer 3, a repair layer 4, an armor layer 5, and a polyurethane outer sheath 6. Cable core 1 includes tensile rope 101, power core 102, control core 103 and optical fiber 104; The manufacturing process of cable core 1 is as follows: multiple power cores 102 are first wrapped around the tensile rope 101 and fixed by twisting to obtain a stranded core. Control core 103 and optical fiber 104 are placed on the outside of both sides of the stranded core, and then fixed by wrapping with water-blocking tape 2 to obtain cable core 1 with water-blocking tape 2.

[0020] Among them, the tensile rope 101 is made of Kevlar fiber. The material (such as nylon fiber as a substitute to reduce costs) and size can be selected according to cost and tensile requirements of the dragging environment. The power core 102 includes, from the inside out, a copper conductor core 102A, a cross-linked polyethylene (XLPE) insulation layer 102B, and a copper tape shielding layer 102C. The copper conductor core 102A is made of multiple strands of copper conductors twisted together, which improves the bending resistance of the cable. The space between the copper conductor core 102A and the cross-linked polyethylene insulation layer 102B is filled with heat dissipation filler 102D. The heat dissipation filler 102D is made of paraffin wax, hydrotalcite and nano calcium carbonate (particle size of 100-500nm) in a weight ratio of 5:3-4:1-2. Hydrotalcite also has a certain water-blocking effect.

[0021] The control core 103 includes a signal wire 103A, a PVC insulation sheath 103B, a wrapping tape 103C, and a cross-linked polyethylene inner sheath 103D. The signal wire 103A is covered with a PVC insulation sheath 103B. The multi-strand signal wires 103A with PVC insulation sheath 103B are bundled together and then wrapped and secured by the wrapping tape 103C. Subsequently, the cross-linked polyethylene inner sheath 103D is extruded. The PVC insulation sheath 103B is a high-performance insulating grade PVC cable material (Luoyang Weiqiang Plastics Co., Ltd.), and is available in various colors for marking different signal wires. The optical fiber 104 comprises, from the inside out, a core 104A, an inner cladding 104B, an inner coating 104C, and an outer coating 104D. The inner cladding 104B is fluorine-doped silicon dioxide (F-SiO2), with an F doping concentration of 0.1-1 wt% (to reduce the refractive index and form optical confinement), and its diameter is 6-8 times that of the core. The inner coating 104C is a low-modulus UV-curable acrylate resin with a modulus of 0.1-1 MPa (for soft buffering) and a thickness of 30-40 μm. The outer coating 104D is a high-modulus UV-curable epoxy acrylate with a modulus of 1000-2000 MPa (for rigid protection) and a thickness of 25-35 μm. Water-blocking tape 2 is a polyester non-woven water-blocking tape (DL water-blocking tape, Jiangsu Taiyuan Cable Material Co., Ltd., mainly made of polyester non-woven fabric, adhesive, high-speed expanding polymer water-absorbing resin and other materials), which absorbs water and expands, thereby improving the sealing performance of the cable core; The preparation process of modified PVC insulation layer 3 is as follows: 1) PVC swelling: PVC granules (PVC purity ≥ 99%) and tetrahydrofuran (THF) were mixed at a weight ratio of 1:10 and swelled at 50℃ for 60 minutes (to avoid softening and deformation of PVC) to obtain PVC swelling material with a swelling rate of 40.2%. 2) Grafting reaction: PVC swelling material, vinyltriethoxysilane (VTES) and benzoyl peroxide (BPO) were mixed in a weight ratio of 10:12:0.5 and reacted at 70°C under oxygen-free sealed conditions for 4 hours to obtain silane-modified PVC. 3) Hydrolysis and condensation: Silane-modified PVC, mercaptopropyltrimethoxysilane, nano-silica (particle size 20-50nm), aqueous acetic acid solution and titanate catalyst were reacted at 60℃ in a weight ratio of 100:5:10:15:0.1 and pH 4.5 for 8 hours in a sealed environment to obtain silicon crosslinked PVC. 4) Squeezing: Modified PVC granules were obtained by extruding silicone crosslinked PVC, liquid barium zinc stabilizer (to inhibit HCl release), and trioctyl trimellitate (TOTM) in a weight ratio of 100:7:15 through a twin-screw extruder. Modified PVC granules are softened at 115°C and extruded onto the water-blocking strip 2 of the cable core 1 to obtain the modified PVC insulation layer 3.

[0022] The preparation process of repair layer 4 is as follows: Hydrotalcite was calcined at 480℃ for 6 hours and then cooled to room temperature to obtain calcined hydrotalcite powder. Subsequently, calcined hydrotalcite, benzotriazole, and water were mixed to form a suspension with a solid content of 10%. The suspension was then mixed for 20-30 minutes at 1000-1500 r / min and 90-95℃ using a homogenizer. After centrifugation, the precipitate was washed with water and dried to obtain benzotriazole (BTA) intercalated hydrotalcite. Subsequently, benzotriazole intercalated hydrotalcite, modified PVC granules, and zinc powder were mixed and softened at 125-135℃. The mixture was then extruded onto the outside of modified PVC insulation layer 3 with a thickness of 5-6% of modified PVC insulation layer 3. The weight ratio of modified PVC granules, benzotriazole, hydrotalcite, and zinc powder was 10:20:35:3.

[0023] The armor layer 5 is a single-layer shielding armor protection layer formed by multiple steel wires spirally wrapped around the repair layer 4.

[0024] The polyurethane outer sheath 6 is a watertight sheath made of TPU foam (zero buoyancy PUR sheath, Shanghai Yixing Industrial Co., Ltd.).

[0025] Example 2 The rest is the same as in Example 1, except that the preparation process of the modified PVC insulation layer 3 is as follows: 1) PVC swelling: PVC granules (PVC purity ≥ 99%) and tetrahydrofuran (THF) were mixed at a weight ratio of 1:10 and swelled at 55℃ for 45 minutes (to avoid softening and deformation of PVC) to obtain PVC swelling material with a swelling rate of 42.5%. 2) Grafting reaction: PVC swelling material, vinyltriethoxysilane (VTES) and benzoyl peroxide (BPO) were mixed in a weight ratio of 10:13:0.8 and reacted at 75°C under oxygen-free sealed conditions for 2-4 hours to obtain silane-modified PVC. 3) Hydrolysis and condensation: Silane-modified PVC, mercaptopropyltrimethoxysilane, nano-silica (particle size 20-50nm), aqueous acetic acid solution and titanate catalyst were reacted at 60℃ for 7h in a weight ratio of 100:6:8:16:0.15 and pH 4.8 to obtain silicon crosslinked PVC. 4) Squeezing: Modified PVC granules were obtained by extruding silicone crosslinked PVC, liquid barium zinc stabilizer (to inhibit HCl release), and trioctyl trimellitate (TOTM) at a weight ratio of 100:6.5:18 through a twin-screw extruder. Modified PVC granules are softened at 120°C and extruded onto the water-blocking strip 2 of the cable core 1 to obtain the modified PVC insulation layer 3.

[0026] Example 3 The rest is the same as in Example 1, except that the preparation process of the modified PVC insulation layer 3 is as follows: 1) PVC swelling: PVC granules (PVC purity ≥ 99%) and tetrahydrofuran (THF) were mixed at a weight ratio of 1:10 and swelled at 60℃ for 30 minutes (to avoid softening and deformation of PVC) to obtain PVC swelling material with a swelling rate of 44.8%. 2) Grafting reaction: PVC swelling material, vinyltriethoxysilane (VTES) and benzoyl peroxide (BPO) were mixed in a weight ratio of 10:15:0.5 and reacted at 80°C under oxygen-free sealed conditions for 2 hours to obtain silane-modified PVC. 3) Hydrolysis and condensation: Silane-modified PVC, mercaptopropyltrimethoxysilane, nano-silica (particle size 20-50nm), aqueous acetic acid solution and titanate catalyst were reacted at 60℃ in a weight ratio of 100:7:7:18:0.2 and pH 5.2 for 6 hours in a sealed environment to obtain silicon crosslinked PVC. 4) Squeezing: Modified PVC granules were obtained by extruding silicone crosslinked PVC, liquid barium zinc stabilizer (to inhibit HCl release), and trioctyl trimellitate (TOTM) in a weight ratio of 100:6:20 through a twin-screw extruder. Modified PVC granules are softened at 125°C and extruded onto the water-blocking strip 2 of the cable core 1 to obtain the modified PVC insulation layer 3.

[0027] Example 4 The rest is the same as in Example 1, except that the preparation process of repair layer 4 is as follows: Hydrotalcite was calcined at 500℃ for 5 hours and then cooled to room temperature to obtain calcined hydrotalcite powder. Subsequently, calcined hydrotalcite, benzotriazole, and water were mixed to form a suspension with a solid content of 10%. The suspension was then mixed for 20-30 minutes at 1000-1500 r / min and 90-95℃ using a homogenizer. After centrifugation, the precipitate was washed with water and dried to obtain benzotriazole (BTA) intercalated hydrotalcite. Subsequently, benzotriazole intercalated hydrotalcite, modified PVC granules, and zinc powder were mixed and softened at 130℃. The mixture was then extruded onto the outside of modified PVC insulation layer 3 with a thickness of 5-6% of modified PVC insulation layer 3. The weight ratio of modified PVC granules, benzotriazole, hydrotalcite, and zinc powder was 10:23:32:3.5.

[0028] Example 5 The rest is the same as in Example 1, except that the preparation process of repair layer 4 is as follows: Hydrotalcite was calcined at 520℃ for 4 hours and then cooled to room temperature to obtain calcined hydrotalcite powder. Subsequently, calcined hydrotalcite, benzotriazole, and water were mixed to form a suspension with a solid content of 10%. The suspension was mixed for 20-30 minutes at 1000-1500 r / min and 90-95℃ using a homogenizer. After centrifugation, the precipitate was washed with water and dried to obtain benzotriazole (BTA) intercalated hydrotalcite. Then, benzotriazole intercalated hydrotalcite, modified PVC granules, and zinc powder were mixed, softened at 135℃, and extruded onto the outside of modified PVC insulation layer 3 with a thickness of 5-6% of modified PVC insulation layer 3. The weight ratio of modified PVC granules, benzotriazole, hydrotalcite, and zinc powder was 10:25:30:4.

[0029] Comparative Example 1 The rest is the same as in Example 1, except that the repair layer 4 is removed and the armor layer 5 is directly wrapped around the modified PVC insulation layer 3.

[0030] Comparative Example 2 The rest is the same as in Example 1, except that the repair layer 4 uses calcined hydrotalcite without BTA intercalation. The preparation process of the repair layer 4 is as follows: Hydrotalcite was calcined at 520℃ for 4 hours and then cooled to room temperature to obtain calcined hydrotalcite powder. Subsequently, calcined hydrotalcite, benzotriazole, modified PVC granules and zinc powder were mixed, softened at 125℃, and extruded onto the outside of modified PVC insulation layer 3 with a thickness of 5-6% of modified PVC insulation layer 3. The weight ratio of modified PVC granules, benzotriazole, hydrotalcite and zinc powder was 10:20:35:3.

[0031] Comparative Example 3 The rest is the same as in Example 1, except that zinc powder was not added to the repair layer 4.

[0032] Comparative Example 4 The rest is the same as in Example 1, except that the preparation process of the modified PVC insulation layer 3 is as follows: 1) Hydrolysis reaction: PVC particles, vinyltriethoxysilane (VTES), benzoyl peroxide (BPO), mercaptopropyltrimethoxysilane, nano-silica (particle size 20-50 nm), aqueous acetic acid solution, and titanate catalyst were mixed according to the actual usage amount in Example 1, with pH 5.6, and reacted in a sealed environment at 60°C for 8 hours to obtain silicon crosslinked PVC. 2) Squeezing: Modified PVC granules were obtained by extruding silicone crosslinked PVC, liquid barium zinc stabilizer (to inhibit HCl release), and trioctyl trimellitate (TOTM) in a weight ratio of 100:7:15 through a twin-screw extruder. Modified PVC granules are softened at 115°C and extruded onto the water-blocking strip 2 of the cable core 1 to obtain the modified PVC insulation layer 3.

[0033] Comparative Example 5 The rest is the same as in Example 1, except that the preparation process of the modified PVC insulation layer 3 is as follows: Modified PVC granules were obtained by extruding PVC granules (PVC purity ≥ 99%), liquid barium zinc stabilizer (to inhibit HCl release), and trioctyl trimellitate (TOTM) in a weight ratio of 100:7:15 through a twin-screw extruder. Modified PVC granules are softened at 115°C and extruded onto the water-blocking strip 2 of the cable core 1 to obtain the modified PVC insulation layer 3.

[0034] II. Performance Testing 1. Testing Method 1) Salt spray test (corrosion resistance of metal parts) Following the method of standard ASTM B117, the cable samples of Examples 1-5 and Comparative Examples 1-5 were subjected to continuous spraying of 5% NaCl solution at 35°C for 3000 hours to test the corrosion rate of the copper conductor and armored steel wire, and the average value of the two was taken. Copper strip corrosion rate (%) = (mass before corrosion - mass after corrosion) / mass before corrosion × 100%; For armored steel wire, the percentage of rusted area is taken as follows:

[0035] 2) UV-accelerated aging (polymer layer resists photoaging) Following the standard ASTM G154 method, UVA-340 lamps were used in the QUV ultraviolet aging chamber at a power of 0.89 W / m². 2Irradiation was applied at 60°C for 8 hours, followed by condensation at 50°C for 4 hours. This process was repeated until the aging cycle was 2000 hours. The tensile strength retention rate (%) of the aged samples was then measured.

[0036] 3) Damp heat aging (overall damp heat resistance) According to the method of standard IEC60068-2-78, the damp heat insulation resistance change rate (%) was tested after being placed at 85℃±2℃ and 85%RH for 1000 hours.

[0037] 4) Repair layer effectiveness test Cross-shaped scratches (depth ≥ 50% of layer thickness, length 20 mm) were made on the surface of the modified PVC insulation layer with a blade to expose the internal copper strip shielding layer (simulating the electrolyte intrusion path after armor damage). The damaged sample was placed in a salt spray chamber (ASTM B117) and continuously sprayed with a 5% NaCl solution at 35°C for 72 hours. After that, it was removed, pickled to remove rust, weighed, and the repair efficiency (%) was measured. (Corrosion rate of damaged sample - Corrosion rate of undamaged sample) / Corrosion rate of damaged sample × 100%.

[0038] 5) Volume resistivity (insulating layer) Following the method of standard IEC 60250, the volume resistivity is obtained by taking a sample of modified PVC insulation sheet (1 mm thick) using a three-electrode system (main electrode diameter 50 mm) after stabilization at 500 VDC for 60 s.

[0039] 6) Thermal aging test According to the method of standard IEC 60811-501, the product was placed in an air-circulating oven at 115℃±2℃ for 7 days, and the heat aging mass loss (%) was tested = (mass before aging - mass after aging) / mass before aging × 100%.

[0040] 2. Test Results Table 1. Influence of different processes on cable performance

[0041] Compared with Example 1, the absence of the repair layer in Comparative Examples 1-3 resulted in a significant increase in corrosion rate (mainly referring to steel wire armor) and poor aging resistance. The lack of coating treatment with corrosion inhibitor (BTA) and the absence of zinc powder also led to a decrease in corrosion resistance. Comparing Comparative Examples 4-5 with Example 1, in Comparative Example 4, the reaction between silicon and unswollen PVC easily leads to nano-agglomeration; Comparative Example 5, lacking silicon, shows a significant decrease in both anti-aging and corrosion resistance. In contrast, Examples 1-5 all possess a complete silicon cross-linked network, making the PVC hydrophobic, while maintaining a volume resistivity greater than 8 × 10⁻⁶. 13Thermal aging loss <1.2%.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A corrosion-resistant and anti-aging cable, characterized in that, From the inside out, it includes the cable core (1), water-blocking tape (2), modified PVC insulation layer (3), repair layer (4), armor layer (5) and polyurethane outer sheath (6). The cable core (1) includes a tensile rope (101), a power core (102), a control core (103), and an optical fiber (104). The preparation process of the modified PVC insulation layer (3) is as follows: 1) PVC swelling: PVC granules and tetrahydrofuran are mixed at a weight ratio of 1:10 and swelled at 50-60℃ for 30-60 minutes to obtain PVC swelling material with a swelling rate of 40-45%. 2) Grafting reaction: PVC swelling material, vinyltriethoxysilane and benzoyl peroxide are mixed in a weight ratio of 10:12-15:0.5-1 and reacted at 70-80℃ under oxygen-free sealed conditions for 2-4 hours to obtain silane-modified PVC. 3) Hydrolysis and condensation: Silane-modified PVC, mercaptopropyltrimethoxysilane, nano-silica, aqueous acetic acid solution and titanate catalyst were reacted at 60℃ in a sealed environment for 6-8 hours with a weight ratio of 100:5-7:7-10:15-18:0.1-0.2 and a pH of 4.5-5.2 to obtain silicon crosslinked PVC. 4) Squeezing: Modified PVC granules were obtained by extruding silicone crosslinked PVC, liquid barium zinc stabilizer, and trioctyl trimellitate in a weight ratio of 100:6-7:15-20 through a twin-screw extruder. Modified PVC granules are softened at 115-125℃ and extruded onto the water-blocking strip (2) of the cable core (1) to obtain a modified PVC insulation layer (3).

2. The anti-corrosion and anti-aging cable according to claim 1, characterized in that, The manufacturing process of the cable core (1) is as follows: multiple power cores (102) are first wrapped around the tensile rope (101), and the stranded core is obtained by twisting and fixing. Control core (103) and optical fiber (104) are placed on the outside of both sides of the stranded core, and then the cable core (1) with water-blocking tape (2) is obtained.

3. The anti-corrosion and anti-aging cable according to claim 1, characterized in that, The tensile rope (101) is made of Kevlar fiber or nylon fiber; The power core (102) comprises, from the inside out, a copper conductor core (102A), a cross-linked polyethylene (XLPE) insulation layer (102B), and a copper strip shielding layer (102C). The copper conductor core (102A) is formed by stranding multiple copper conductors together. The space between the copper conductor core (102A) and the cross-linked polyethylene insulation layer (102B) is filled with heat dissipation filler (102D), which is composed of paraffin wax, hydrotalcite and nano calcium carbonate in a weight ratio of 5:3-4:1-2. The control core (103) includes a signal line (103A), a PVC insulation sheath (103B), a wrapping tape (103C), and a cross-linked polyethylene inner sheath (103D). The signal line (103A) is covered with a PVC insulation sheath (103B). Multiple strands of the signal line (103A) with PVC insulation sheath (103B) are bundled together and then wrapped and secured with the wrapping tape (103C), followed by extrusion of the cross-linked polyethylene inner sheath (103D). The PVC insulation sheath (103B) is a high-performance electrical insulation grade PVC cable material. The optical fiber (104) comprises, from the inside out, a core (104A), an inner cladding (104B), an inner coating (104C), and an outer coating (104D); the inner cladding (104B) is fluorine-doped silicon dioxide; the inner coating (104C) is a low-modulus UV-curable acrylate resin with a modulus of 0.1-1 MPa; and the outer coating (104D) is a high-modulus UV-curable epoxy acrylate with a modulus of 1000-2000 MPa.

4. The anti-corrosion and anti-aging cable according to claim 1, characterized in that, The water-blocking tape (2) is a polyester non-woven water-blocking tape.

5. The anti-corrosion and anti-aging cable according to claim 1, characterized in that, The preparation process of the repair layer (4) is as follows: The hydrotalcite was calcined at 480-520℃ for 4-6 hours and then cooled to room temperature. The resulting powder was calcined hydrotalcite. The calcined hydrotalcite, benzotriazole and water were then mixed to form a suspension with a solid content of 10%. The suspension was mixed for 20-30 minutes at 1000-1500 r / min and 90-95℃ using a homogenizer. The mixture was then centrifuged, and the precipitate was washed and dried to obtain benzotriazole-intercalated hydrotalcite. The benzotriazole-intercalated hydrotalcite, modified PVC granules and zinc powder were then mixed and softened at 125-135℃. The mixture was then extruded onto the outside of the modified PVC insulation layer (3) with a thickness of 5-6% of the modified PVC insulation layer (3).

6. The anti-corrosion and anti-aging cable according to claim 5, characterized in that, The weight ratio of the modified PVC granules, benzotriazole, hydrotalcite, and zinc powder is 10:20-25:30-35:3-4.

7. The anti-corrosion and anti-aging cable according to claim 1, characterized in that, The armor layer (5) is a single-layer shielding armor protection layer formed by multiple steel wires spirally wrapped around the repair layer (4).

8. The anti-corrosion and anti-aging cable according to claim 1, characterized in that, The polyurethane outer sheath (6) is a watertight sheath made of TPU foam.

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