Corrosion-resistant insulated cable and preparation method thereof

Abstract

The invention discloses a corrosion-resistant insulated cable and a preparation method thereof, and relates to the technical field of polypropylene. The corrosion-resistant insulated cable comprises a conductor, an insulating layer, an armor layer and a sheath layer from inside to outside. The sheath layer is prepared from the following raw materials in parts by mass: 70 to 80 parts of polypropylene, 20 to 30 parts of blended polypropylene, 16 to 20 parts of ethylene-propylene-hexene copolymer, 0.01 to 0.05 part of composite nucleating agent, 0.2 to 0.3 part of antioxidant, 5 to 10 parts of compatilizer, 2 to 5 parts of reinforcing filler and 0.5 to 1 part of silane modified zirconium oxide; wherein the composite nucleating agent consists of a beta crystal form aromatic amide nucleating agent and an alpha crystal form carboxylate nucleating agent in a mass ratio of 1: (0.5-0.8); the armor layer is formed by winding galvanized steel wires in a spiral structure, and the winding angle ranges from 15 degrees to 25 degrees.

Description

Technical Field

[0001] This invention relates to the field of polypropylene technology, specifically to a corrosion-resistant insulated cable and its preparation method. Background Technology

[0002] Power and communication cables are the lifeline of energy and information transmission in modern society. In special environments such as marine development, coastal areas, chemical plants, and mines, cables are exposed to complex corrosive environments with high humidity, high salt spray, chemical media, and microorganisms for extended periods, posing a severe challenge to their reliability. Cable failure often begins with its outermost sheath. Corrosion, aging, and cracking of the sheath will lead to the direct exposure and accelerated deterioration of the internal metal armor, insulation layer, and even conductor, causing serious accidents such as insulation degradation, short circuits, and even fires.

[0003] Traditional cable sheathing materials, such as polyvinyl chloride and polyethylene, have certain chemical resistance, but they are significantly insufficient in long-term, harsh corrosive environments. Polypropylene, as a semi-crystalline thermoplastic polymer, is considered a promising matrix material in the field of cable sheathing due to its excellent chemical stability, low density, good electrical insulation, and relatively low cost. However, unmodified polypropylene still has many inherent defects such as insufficient toughness and insufficient corrosion resistance.

[0004] Therefore, there is an urgent need to develop a corrosion-resistant insulated cable to adapt to complex corrosive environments. Summary of the Invention

[0005] The purpose of this invention is to provide a corrosion-resistant insulated cable and its preparation method to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A corrosion-resistant insulated cable comprises, from the inside out, a conductor, an insulation layer, an armor layer, and a sheath layer; the sheath layer comprises the following raw materials in parts by weight: 70-80 parts polypropylene, 20-30 parts blended polypropylene, 16-20 parts ethylene-propylene-hexene copolymer, 0.01-0.05 parts composite nucleating agent, 0.2-0.3 parts antioxidant, 5-10 parts compatibilizer, 1-3 parts reinforcing filler, and 0.5-1 parts silane-modified zirconium oxide;

[0008] Preferably, the blended polypropylene is obtained by blending random copolymer polypropylene and polyolefin elastomer at a mass ratio of 1:0.3~0.5 and granulating; the blending process parameters are: inlet temperature of 180~190℃, outlet temperature of 190~205℃, stirring speed of 120~160r / min, and stirring time of 30~40min;

[0009] Preferably, the composite nucleating agent consists of a β-crystalline aromatic amide nucleating agent and an α-crystalline carboxylate nucleating agent in a mass ratio of 1:0.5~0.8; the compatibilizer is maleic anhydride-grafted polypropylene.

[0010] Preferably, the preparation steps of the reinforcing filler are as follows:

[0011] S1: Montmorillonite and ammonia were ultrasonically dispersed in anhydrous ethanol. Tetraethyl orthosilicate and anhydrous ethanol were mixed, and the above montmorillonite mixture was added. After stirring for 6-8 hours, the mixture was filtered and dried to obtain composite particles. The composite particles were placed in deionized water, a dispersant was added, and the mixture was stirred for 2-3 hours. After washing and centrifugation, the particles were dried and pulverized to obtain modified composite particles. The modified composite particles were placed in deionized water, sodium carbonate was added, and the mixture was heated to 75-80℃ and stirred for 2-3 hours. After cooling to 60-70℃, a dispersant was added and the mixture was stirred for 2-3 hours. After filtration and drying, the mixture is ultrasonically dispersed in deionized water for 20-30 minutes. Polyethylene glycol is added and stirred for 10-20 minutes. Gelatin is then added and stirred at 35-45°C for 20-30 minutes. Azobisisobutyronitrile and methyl methacrylate are added, and the mixture is heated to 65-70°C and reacted for 3-4 hours. The temperature is then raised to 80-85°C and reacted for 0.5-1 hour. The mixture is filtered, washed, and dried at 50°C for 20-24 hours. After heating to 80-110°C for 1-3 hours, the mixture is then placed in an ice-water bath to obtain porous modified composite particles.

[0012] S2: N-vinylformamide, 1H,1H,2H-perfluoro-1-decene, and azobisisobutyronitrile were placed in tetrahydrofuran and reacted at 65-70℃ under a nitrogen atmosphere for 8-10 hours. After filtration and washing, the mixture was dried and placed in ethanol. Sodium hydroxide was added, and the mixture was reacted at 70-75℃ under a nitrogen atmosphere for 48 hours. After rotary evaporation and drying, the mixture was placed in ethanol, hydroiodic acid was added, and the mixture was reacted at -1-0℃ in the dark for 20-24 hours. After filtration and washing, the mixture was placed in ethanol, porous modified composite particles were added, and the mixture was stirred for 2-4 hours. After rotary evaporation and drying, the reinforced filler was obtained.

[0013] Preferably, the composite particles in S1 include the following raw material components: by mass, 8-10 parts montmorillonite, 18-20 parts ammonia water, and 45-50 parts tetraethyl orthosilicate; the mass ratio of composite particles to dispersant is 1:0.1-0.3.

[0014] Preferably, the porous modified composite particles in S1 include the following raw material components: by mass, 10-12 parts modified composite particles, 0.8-1 parts sodium carbonate, 1-2 parts dispersant, 2-4 parts polyethylene glycol, 1-1.5 parts gelatin, 0.5-1 parts azobisisobutyronitrile, and 40-50 parts methyl methacrylate;

[0015] Preferably, the reinforcing filler in S2 comprises the following raw material components: by mass, 0.6~0.9 parts N-vinylformamide, 0.4~0.6 parts 1H,1H,2H-perfluoro-1-decene, 0.02~0.03 parts azobisisobutyronitrile, 0.8~0.9 parts sodium hydroxide, 2.5~2.8 parts hydroiodic acid, and 10~15 parts porous modified composite particles;

[0016] Preferably, the insulation layer is made of thermoplastic cable insulation material;

[0017] Preferably, the armor layer is formed by spirally winding galvanized steel wire at an angle of 15° to 25°.

[0018] A method for preparing a corrosion-resistant insulated cable includes the following preparation steps: after sequentially setting an insulation layer and an armor layer outside the conductor, a mixed sheath layer is extruded onto the outer surface of the armor layer to obtain the corrosion-resistant insulated cable;

[0019] Preferably, the preparation steps of the sheath layer compound are as follows: polypropylene, blended polypropylene, compatibilizer, reinforcing filler and composite nucleating agent are mixed and stirred at 180~190℃ at 40~60r / min for 6~10min, then silane-modified zirconium oxide and ethylene~propylene~hexene copolymer are added, and stirred at 180~190℃ at 50~60r / min for 6~8min, and then extruded and granulated.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0021] This invention, based on polypropylene, incorporates blended polypropylene and ethylene-propylene-hexene copolymer to improve the inherent brittleness of polypropylene and provide a toughening effect. During the melting process, composite nucleating agents are added, including α / β composite nucleating agents. The β-crystal nucleating agent induces the formation of more resilient β-crystals within the polymer, while the α-crystal nucleating agent refines the grains, improving the overall strength and thermal stability of the polymer. The synergistic compounding optimizes the mechanical properties of the polymer. Reinforcing fillers are added, using in-situ grown silica from montmorillonite as the main core structure, and polyethylene glycol as a template agent to polymerize monomers on the surface of the SiO2-MMT composite material, followed by thermoforming. The template agent is removed to obtain porous microspheres. A perfluorinated surfactant carrying ammonium ions is used to functionalize the surface of the porous microspheres, simultaneously fixing the material on the surface and inside of the microspheres. This optimizes defects such as surface segregation caused by chain segment recombination and movement during subsequent melting, improving the water resistance of the outer sheath layer. The reinforcing filler provides a barrier effect, while silane-modified zirconium oxide fills the gaps, creating multiple barrier layers to delay the erosion of corrosive media and further improve its corrosion resistance as a sheath layer. Antioxidants are added to resist thermal aging, and compatibilizers are added to further improve the interfacial compatibility between the filler and polypropylene. The armor layer is spirally wound with galvanized steel wire. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that the following quantities are by weight, and there are no special restrictions on the suppliers of all raw materials involved in this invention. Exemplary examples include:

[0024] The dispersant is hexadecyltrimethylammonium bromide;

[0025] The conductor is copper;

[0026] Montmorillonite was purchased from Shanghai Baishun Biotechnology Co., Ltd., product number 042531;

[0027] The polypropylene is model T30S and the random copolymer polypropylene is model B4101, both of which were purchased from Sinopec.

[0028] The polyolefin elastomer is an ethylene-octene copolymer with an octene content of 20 wt%, model Engage8480, purchased from Dow Chemical Company, USA.

[0029] The composite nucleating agent consists of a β-crystalline aromatic amide nucleating agent and an α-crystalline carboxylate nucleating agent in a mass ratio of 1:0.6; the β-crystalline aromatic amide nucleating agent is N,N'-dicyclohexylterephthalamide; and the α-crystalline carboxylate nucleating agent is calcium hexahydrophthalate.

[0030] The ethylene-propylene-hexene copolymer was purchased from Mitsubishi Corporation of Japan, and its brand name was KernelTM KF360T.

[0031] The compatibilizer was maleic anhydride-grafted polypropylene, model PP-G-MAH, purchased from Nanjing Deba Polymer Materials Co., Ltd.

[0032] The preparation steps of silane-modified zirconium oxide are as follows: 10 parts of zirconium oxide are placed in 100 parts of KH570 solution with a mass concentration of 10%, ultrasonically dispersed for 2 hours, heated to 60℃ and stirred for 4 hours, cooled and filtered, washed and dried to obtain silane-modified zirconium oxide; the zirconium oxide particle size is 100nm and it was purchased from Shanghai MCC New Materials Co., Ltd.

[0033] The insulation layer uses thermoplastic cable insulation material, grade WMPP-J11, purchased from Wanma Polymer.

[0034] The armor layer is made of galvanized steel wire wound in a spiral structure at an angle of 18°.

[0035] In the following examples, parts refer to parts by weight, and all raw materials mentioned above and others not mentioned are commercially available.

[0036] Example 1: A method for preparing a corrosion-resistant cable, comprising the following preparation steps:

[0037] Step 1: Preparation of reinforcing filler:

[0038] S1: Add 10 parts montmorillonite and 20 parts ammonia to 80 parts anhydrous ethanol and ultrasonically disperse for 30 min. Mix 45 parts tetraethyl orthosilicate and 120 parts anhydrous ethanol, add the above montmorillonite mixture, stir for 8 h, filter and dry to obtain composite particles. Place 10 parts of composite particles in 100 parts deionized water, add 3 parts dispersant, stir for 3 h, wash, centrifuge, dry and pulverize to obtain modified composite particles. Place 10 parts of modified composite particles in 100 parts deionized water, add 1 part sodium carbonate, heat to 75℃ and stir. After 3 hours, the temperature was lowered to 60°C, 2 parts of dispersant were added and stirred for 3 hours, then filtered and dried. The mixture was then placed in 100 parts of deionized water and ultrasonically dispersed for 30 minutes. 3 parts of polyethylene glycol were added and stirred for 20 minutes, then 1 part of gelatin was added. After stirring at 45°C for 30 minutes, 0.5 parts of azobisisobutyronitrile and 48 parts of methyl methacrylate were added. The temperature was raised to 70°C and reacted for 4 hours, then raised to 85°C and reacted for 1 hour. The mixture was filtered, washed, dried at 50°C for 24 hours, heated to 90°C for 2 hours, and then subjected to an ice-water bath to obtain porous modified composite particles.

[0039] S1.2: 0.8 parts of N-vinylformamide, 0.5 parts of 1H,1H,2H-perfluoro-1-decene, and 0.03 parts of azobisisobutyronitrile were placed in 20 parts of tetrahydrofuran. The mixture was heated to 70℃ in a nitrogen atmosphere and reacted for 8 hours. After filtration and washing, the mixture was dried and placed in 50 parts of ethanol. 0.8 parts of sodium hydroxide were added, and the mixture was heated to 75℃ in a nitrogen atmosphere and reacted for 48 hours. After rotary evaporation and drying, the mixture was placed in 50 parts of ethanol. 2.6 parts of hydroiodic acid were added, and the mixture was reacted in the dark at 0℃ for 24 hours. After filtration and washing, the mixture was placed in 100 parts of ethanol. 12 parts of porous modified composite particles were added, and the mixture was stirred for 3 hours. After rotary evaporation and drying, the reinforced filler was obtained.

[0040] Step 2: Blend random copolymer polypropylene and polyolefin elastomer into granules at a mass ratio of 1:0.5; wherein the blending process parameters are: inlet temperature 180℃, outlet temperature 190℃, stirring speed 120r / min, and stirring time 40min.

[0041] Step 3: Mix polypropylene, blended polypropylene, compatibilizer, reinforcing filler, and composite nucleating agent. Stir and blend at 50 r / min for 8 min at 190℃. Then add silane-modified zirconium oxide and ethylene-propylene-hexene copolymer. Stir and blend at 60 r / min for 6 min at 190℃. Extrude and granulate. The raw materials in Step 3 include the following components: 75 parts polypropylene, 25 parts blended polypropylene, 18 parts ethylene-propylene-hexene copolymer, 0.03 parts composite nucleating agent, 0.3 parts antioxidant, 8 parts compatibilizer, 3 parts reinforcing filler, and 0.8 parts silane-modified zirconium oxide.

[0042] Step 4: After sequentially setting the insulation layer and armor layer outside the conductor, the mixed sheath layer is extruded onto the outer surface of the armor layer to obtain a corrosion-resistant insulated cable.

[0043] Example 2: A method for preparing a corrosion-resistant cable, comprising the following preparation steps:

[0044] Step 1: Preparation of reinforcing filler:

[0045] S1: Add 10 parts montmorillonite and 20 parts ammonia to 80 parts anhydrous ethanol and ultrasonically disperse for 30 min. Mix 45 parts tetraethyl orthosilicate and 120 parts anhydrous ethanol, add the above montmorillonite mixture, stir for 6-8 h, filter and dry to obtain composite particles. Place 10 parts of composite particles in 100 parts deionized water, add 3 parts dispersant, stir for 3 h, wash, centrifuge, dry and pulverize to obtain modified composite particles. Take 10 parts of modified composite particles and place in 100 parts deionized water, add 1 part sodium carbonate, heat to 80℃ and stir. After stirring for 2 hours, the temperature was lowered to 65°C, 2 parts of dispersant were added and stirred for 3 hours, then filtered and dried. The mixture was placed in 100 parts of deionized water and ultrasonically dispersed for 20 minutes. 3 parts of polyethylene glycol were added and stirred for 20 minutes, then 1 part of gelatin was added. After stirring at 45°C for 30 minutes, 0.5 parts of azobisisobutyronitrile and 48 parts of methyl methacrylate were added. The temperature was raised to 70°C and reacted for 4 hours, then raised to 85°C and reacted for 1 hour. The mixture was filtered and washed, dried at 50°C for 24 hours, then heated to 85°C for 3 hours and then subjected to an ice-water bath to obtain porous modified composite particles.

[0046] S1.2: 0.8 parts of N-vinylformamide, 0.5 parts of 1H,1H,2H-perfluoro-1-decene, and 0.03 parts of azobisisobutyronitrile were placed in 20 parts of tetrahydrofuran. The mixture was heated to 70°C in a nitrogen atmosphere and reacted for 10 hours. After filtration and washing, the mixture was dried and placed in 50 parts of ethanol. 0.8 parts of sodium hydroxide were added, and the mixture was heated to 75°C in a nitrogen atmosphere and reacted for 48 hours. After rotary evaporation and drying, the mixture was placed in 50 parts of ethanol. 2.6 parts of hydroiodic acid were added, and the mixture was reacted at 0°C in the dark for 24 hours. After filtration and washing, the mixture was placed in dichloromethane and placed in 100 parts of ethanol. 12 parts of porous modified composite particles were added, and the mixture was stirred for 4 hours. After rotary evaporation and drying, the reinforced filler was obtained.

[0047] Step 2: Blend random copolymer polypropylene and polyolefin elastomer into granules at a mass ratio of 1:0.3; wherein the blending process parameters are: inlet temperature 180℃, outlet temperature 200℃, stirring speed 160r / min, and stirring time 30min.

[0048] Step 3: Mix polypropylene, blended polypropylene, compatibilizer, reinforcing filler, and composite nucleating agent. Stir and blend at 190℃ and 60 r / min for 6 min. Then add silane-modified zirconium oxide and ethylene-propylene-hexene copolymer. Stir and blend at 190℃ and 50 r / min for 6 min. Extrude and granulate. The raw materials in Step 3 include the following components: 75 parts polypropylene, 25 parts blended polypropylene, 18 parts ethylene-propylene-hexene copolymer, 0.03 parts composite nucleating agent, 0.2 parts antioxidant, 8 parts compatibilizer, 2 parts reinforcing filler, and 0.5 parts silane-modified zirconium oxide.

[0049] Step 4: After sequentially setting the insulation layer and armor layer outside the conductor, the mixed sheath layer is extruded onto the outer surface of the armor layer to obtain a corrosion-resistant insulated cable.

[0050] Example 3: A method for preparing a corrosion-resistant cable, comprising the following preparation steps:

[0051] Step 1: Preparation of reinforcing filler:

[0052] S1: Add 10 parts montmorillonite and 20 parts ammonia to 80 parts anhydrous ethanol and ultrasonically disperse for 30 min. Mix 45 parts tetraethyl orthosilicate and 120 parts anhydrous ethanol, add the above montmorillonite mixture, stir for 8 h, filter and dry to obtain composite particles. Place 10 parts of composite particles in 100 parts deionized water, add 3 parts dispersant, stir for 3 h, wash, centrifuge, dry and pulverize to obtain modified composite particles. Take 10 parts of modified composite particles and place in 100 parts deionized water, add 1 part sodium carbonate, heat to 80℃ and stir for 3 h. Afterwards, the temperature was lowered to 70℃, 2 parts of dispersant were added and stirred for 2 hours, then filtered and dried. The mixture was then placed in 100 parts of deionized water and ultrasonically dispersed for 30 minutes. 3 parts of polyethylene glycol were added and stirred for 10 minutes, then 1 part of gelatin was added. After stirring at 35℃ for 30 minutes, 0.5 parts of azobisisobutyronitrile and 48 parts of methyl methacrylate were added. The temperature was raised to 70℃ and reacted for 3 hours, then raised to 80℃ and reacted for 0.5 hours. The mixture was filtered and washed, dried at 50℃ for 24 hours, then heated to 110℃ for 3 hours and then subjected to an ice-water bath to obtain porous modified composite particles.

[0053] S1.2: 0.8 parts of N-vinylformamide, 0.5 parts of 1H,1H,2H-perfluoro-1-decene, and 0.03 parts of azobisisobutyronitrile were placed in 20 parts of tetrahydrofuran. The mixture was heated to 70°C under a nitrogen atmosphere and reacted for 10 hours. After filtration and washing, the mixture was dried and placed in 50 parts of ethanol. 0.8 parts of sodium hydroxide were added, and the mixture was heated to 75°C under a nitrogen atmosphere and reacted for 48 hours. After rotary evaporation and drying, the mixture was placed in 50 parts of ethanol. 2.6 parts of hydroiodic acid were added, and the mixture was reacted at 0°C in the dark for 24 hours. After filtration and washing, the mixture was placed in 100 parts of ethanol. 12 parts of porous modified composite particles were added, and the mixture was stirred for 3 hours. After rotary evaporation and drying, the reinforced filler was obtained.

[0054] Step 2: Blend random copolymer polypropylene and polyolefin elastomer into granules at a mass ratio of 1:0.5; wherein the blending process parameters are: inlet temperature 190℃, outlet temperature 200℃, stirring speed 120r / min, and stirring time 40min.

[0055] Step 3: Mix polypropylene, blended polypropylene, compatibilizer, reinforcing filler, and composite nucleating agent. Stir and blend at 180℃ and 60 r / min for 10 min. Then add silane-modified zirconium oxide and ethylene-propylene-hexene copolymer. Stir and blend at 190℃ and 60 r / min for 8 min. Extrude and granulate. The raw materials in Step 3 include the following components: 75 parts polypropylene, 25 parts blended polypropylene, 18 parts ethylene-propylene-hexene copolymer, 0.03 parts composite nucleating agent, 0.3 parts antioxidant, 8 parts compatibilizer, 2 parts reinforcing filler, and 1 part silane-modified zirconium oxide.

[0056] Step 4: After sequentially setting the insulation layer and armor layer outside the conductor, the mixed sheath layer is extruded onto the outer surface of the armor layer to obtain a corrosion-resistant insulated cable.

[0057] Comparative Example 1: As a control experiment for Example 3, no perfluorinated modification was performed in step 1, specifically including the following steps:

[0058] Step 1: Add 10 parts montmorillonite and 20 parts ammonia to 80 parts anhydrous ethanol and ultrasonically disperse for 30 min. Mix 45 parts tetraethyl orthosilicate and 120 parts anhydrous ethanol, add the above montmorillonite mixture, stir for 8 h, filter and dry to obtain composite particles. Place 10 parts of composite particles in 100 parts deionized water, add 3 parts dispersant, stir for 3 h, wash, centrifuge, dry and pulverize to obtain modified composite particles. Take 10 parts of modified composite particles and place in 100 parts deionized water, add 1 part sodium carbonate, heat to 80℃ and stir. After stirring for 3 hours, the temperature was lowered to 70°C. Two parts of dispersant were added and stirred for 2 hours. The mixture was then filtered and dried. It was placed in 100 parts of deionized water and ultrasonically dispersed for 30 minutes. Three parts of polyethylene glycol were added and stirred for 10 minutes. One part of gelatin was added and stirred at 35°C for 30 minutes. Then, 0.5 parts of azobisisobutyronitrile and 48 parts of methyl methacrylate were added. The temperature was raised to 70°C and reacted for 3 hours. The temperature was then raised to 80°C and reacted for 0.5 hours. The mixture was filtered and washed. After drying at 50°C for 24 hours, it was heated to 110°C for 3 hours and then subjected to an ice-water bath to obtain the reinforcing filler.

[0059] Step 2: Blend random copolymer polypropylene and polyolefin elastomer into granules at a mass ratio of 1:0.5; wherein the blending process parameters are: inlet temperature 190℃, outlet temperature 200℃, stirring speed 120r / min, and stirring time 40min.

[0060] Step 3: Mix polypropylene, blended polypropylene, compatibilizer, reinforcing filler, and composite nucleating agent. Stir and blend at 180℃ and 60 r / min for 10 min. Then add silane-modified zirconium oxide and ethylene-propylene-hexene copolymer. Stir and blend at 190℃ and 60 r / min for 8 min. Extrude and granulate. The raw materials in Step 3 include the following components: 75 parts polypropylene, 25 parts blended polypropylene, 18 parts ethylene-propylene-hexene copolymer, 0.03 parts composite nucleating agent, 0.3 parts antioxidant, 8 parts compatibilizer, 2 parts reinforcing filler, and 1 part silane-modified zirconium oxide.

[0061] Step 4: After sequentially setting the insulation layer and armor layer outside the conductor, the mixed sheath layer is extruded onto the outer surface of the armor layer to obtain a corrosion-resistant insulated cable.

[0062] Comparative Example 2: No porous coating is performed in step 1, specifically including the following steps:

[0063] Step 1: Preparation of reinforcing filler:

[0064] S1: Add 10 parts montmorillonite and 20 parts ammonia to 80 parts anhydrous ethanol and ultrasonically disperse for 30 min. Mix 45 parts tetraethyl orthosilicate and 120 parts anhydrous ethanol, add the above montmorillonite mixture, stir for 8 h, filter and dry to obtain composite particles. Place 10 parts of composite particles in 100 parts deionized water, add 3 parts dispersant, stir for 3 h, wash, centrifuge, dry and pulverize to obtain modified composite particles. Take 10 parts of modified composite particles in 100 parts deionized water, add 1 part sodium carbonate, heat to 80℃ and stir for 3 h, cool to 70℃, add 2 parts dispersant, stir and react for 2 h, filter and dry to obtain reinforced filler.

[0065] Step 2: Blend random copolymer polypropylene and polyolefin elastomer into granules at a mass ratio of 1:0.5; wherein the blending process parameters are: inlet temperature 190℃, outlet temperature 200℃, stirring speed 120r / min, and stirring time 40min.

[0066] Step 3: Mix polypropylene, blended polypropylene, compatibilizer, reinforcing filler, and composite nucleating agent. Stir and blend at 180℃ and 60 r / min for 10 min. Then add silane-modified zirconium oxide and ethylene-propylene-hexene copolymer. Stir and blend at 190℃ and 60 r / min for 8 min. Extrude and granulate. The raw materials in Step 3 include the following components: 75 parts polypropylene, 25 parts blended polypropylene, 18 parts ethylene-propylene-hexene copolymer, 0.03 parts composite nucleating agent, 0.3 parts antioxidant, 8 parts compatibilizer, 2 parts reinforcing filler, and 1 part silane-modified zirconium oxide.

[0067] Step 4: After sequentially setting the insulation layer and armor layer outside the conductor, the mixed sheath layer is extruded onto the outer surface of the armor layer to obtain a corrosion-resistant insulated cable.

[0068] Comparative Example 3: As a control experiment for Example 3, the proportion of polyethylene glycol was increased in step 1, specifically including the following steps:

[0069] Step 1: Preparation of reinforcing filler:

[0070] S1: Add 10 parts montmorillonite and 20 parts ammonia to 80 parts anhydrous ethanol and ultrasonically disperse for 30 min. Mix 45 parts tetraethyl orthosilicate and 120 parts anhydrous ethanol, add the above montmorillonite mixture, stir for 8 h, filter and dry to obtain composite particles. Place 10 parts of composite particles in 100 parts deionized water, add 3 parts dispersant, stir for 3 h, wash, centrifuge, dry and pulverize to obtain modified composite particles. Take 10 parts of modified composite particles and place in 100 parts deionized water, add 1 part sodium carbonate, heat to 80℃ and stir for 3 h. Afterwards, the temperature was lowered to 70℃, 2 parts of dispersant were added and stirred for 2 hours, then filtered and dried. The mixture was then placed in 100 parts of deionized water and ultrasonically dispersed for 30 minutes. 8 parts of polyethylene glycol were added and stirred for 10 minutes, then 1 part of gelatin was added. After stirring at 35℃ for 30 minutes, 0.5 parts of azobisisobutyronitrile and 48 parts of methyl methacrylate were added. The temperature was raised to 70℃ and reacted for 3 hours, then raised to 80℃ and reacted for 0.5 hours. The mixture was filtered and washed, dried at 50℃ for 24 hours, then heated to 110℃ for 3 hours and then subjected to an ice-water bath to obtain porous modified composite particles.

[0071] S1.2: 0.8 parts of N-vinylformamide, 0.5 parts of 1H,1H,2H-perfluoro-1-decene, and 0.03 parts of azobisisobutyronitrile were placed in 20 parts of tetrahydrofuran. The mixture was heated to 70°C under a nitrogen atmosphere and reacted for 10 hours. After filtration and washing, the mixture was dried and placed in 50 parts of ethanol. 0.8 parts of sodium hydroxide were added, and the mixture was heated to 75°C under a nitrogen atmosphere and reacted for 48 hours. After rotary evaporation and drying, the mixture was placed in 50 parts of ethanol. 2.6 parts of hydroiodic acid were added, and the mixture was reacted at 0°C in the dark for 24 hours. After filtration and washing, the mixture was placed in 100 parts of ethanol. 12 parts of porous modified composite particles were added, and the mixture was stirred for 3 hours. After rotary evaporation and drying, the reinforced filler was obtained.

[0072] Step 2: Blend random copolymer polypropylene and polyolefin elastomer into granules at a mass ratio of 1:0.5; wherein the blending process parameters are: inlet temperature 190℃, outlet temperature 200℃, stirring speed 120r / min, and stirring time 40min.

[0073] Step 3: Mix polypropylene, blended polypropylene, compatibilizer, reinforcing filler, and composite nucleating agent. Stir and blend at 180℃ and 60 r / min for 10 min. Then add silane-modified zirconium oxide and ethylene-propylene-hexene copolymer. Stir and blend at 190℃ and 60 r / min for 8 min. Extrude and granulate. The raw materials in Step 3 include the following components: 75 parts polypropylene, 25 parts blended polypropylene, 18 parts ethylene-propylene-hexene copolymer, 0.03 parts composite nucleating agent, 0.3 parts antioxidant, 8 parts compatibilizer, 2 parts reinforcing filler, and 1 part silane-modified zirconium oxide.

[0074] Step 4: After sequentially setting the insulation layer and armor layer outside the conductor, the mixed sheath layer is extruded onto the outer surface of the armor layer to obtain a corrosion-resistant insulated cable.

[0075] Comparative Example 4: As a control experiment for Example 3, the temperature for removing the template agent in S1.1 was adjusted to 50°C, specifically including the following steps:

[0076] Step 1: Preparation of reinforcing filler:

[0077] S1.1: Add 10 parts montmorillonite and 20 parts ammonia to 80 parts anhydrous ethanol and ultrasonically disperse for 30 min. Mix 45 parts tetraethyl orthosilicate and 120 parts anhydrous ethanol, add the above montmorillonite mixture, stir for 8 h, filter and dry to obtain composite particles. Place 10 parts of composite particles in 100 parts deionized water, add 3 parts dispersant, stir for 3 h, wash, centrifuge, dry and pulverize to obtain modified composite particles. Take 10 parts of modified composite particles and place in 100 parts deionized water, add 1 part sodium carbonate, heat to 80℃ and stir. After 3 hours, the temperature was lowered to 70°C, 2 parts of dispersant were added and stirred for 2 hours, then filtered and dried. The mixture was then ultrasonically dispersed in 100 parts of deionized water for 30 minutes, 3 parts of polyethylene glycol were added and stirred for 10 minutes, then 1 part of gelatin was added. After stirring at 35°C for 30 minutes, 0.5 parts of azobisisobutyronitrile and 48 parts of methyl methacrylate were added, the temperature was raised to 70°C and reacted for 3 hours, then raised to 80°C and reacted for 0.5 hours. The mixture was filtered and washed, dried at 50°C for 24 hours, then heated to 50°C for 3 hours and then subjected to an ice-water bath to obtain porous modified composite particles.

[0078] S1.2: 0.8 parts of N-vinylformamide, 0.5 parts of 1H,1H,2H-perfluoro-1-decene, and 0.03 parts of azobisisobutyronitrile were placed in 20 parts of tetrahydrofuran. The mixture was heated to 70°C under a nitrogen atmosphere and reacted for 10 hours. After filtration and washing, the mixture was dried and placed in 50 parts of ethanol. 0.8 parts of sodium hydroxide were added, and the mixture was heated to 75°C under a nitrogen atmosphere and reacted for 48 hours. After rotary evaporation and drying, the mixture was placed in 50 parts of ethanol. 2.6 parts of hydroiodic acid were added, and the mixture was reacted at 0°C in the dark for 24 hours. After filtration and washing, the mixture was placed in 100 parts of ethanol. 12 parts of porous modified composite particles were added, and the mixture was stirred for 3 hours. After rotary evaporation and drying, the reinforced filler was obtained.

[0079] Step 2: Blend random copolymer polypropylene and polyolefin elastomer into granules at a mass ratio of 1:0.5; wherein the blending process parameters are: inlet temperature 190℃, outlet temperature 200℃, stirring speed 120r / min, and stirring time 40min.

[0080] Step 3: Mix polypropylene, blended polypropylene, compatibilizer, reinforcing filler, and composite nucleating agent. Stir and blend at 180℃ and 60 r / min for 10 min. Then add silane-modified zirconium oxide and ethylene-propylene-hexene copolymer. Stir and blend at 190℃ and 60 r / min for 8 min. Extrude and granulate. The raw materials in Step 3 include the following components: 75 parts polypropylene, 25 parts blended polypropylene, 18 parts ethylene-propylene-hexene copolymer, 0.03 parts composite nucleating agent, 0.3 parts antioxidant, 8 parts compatibilizer, 2 parts reinforcing filler, and 1 part silane-modified zirconium oxide.

[0081] Step 4: After sequentially setting the insulation layer and armor layer outside the conductor, the mixed sheath layer is extruded onto the outer surface of the armor layer to obtain a corrosion-resistant insulated cable.

[0082] Performance testing:

[0083] 1. Tensile strength tests were performed on the sheath layer of the cable samples prepared in Examples 1-3 and Comparative Examples 1-4 according to GB / T2951.11. A dumbbell sample with a thickness of 0.8 mm, a length of 50 mm, and a width of 8.5 mm was taken for each group. The test temperature was 25℃ and the moving speed was 30 mm / min. The data are recorded in Table 1.

[0084] 3. Take the cable samples prepared in Examples 1-3 and Comparative Examples 1-4, cut a slice of the sheath layer with a thickness of 0.2 mm, clean it with ethanol, and then treat it in a 3.5% sodium chloride solution (100℃) for 0 h and 1200 h. After cleaning and drying, perform a step-up voltage test at a voltage increase rate of 2 kV / s to measure the breakdown voltage value. Calculate the breakdown field strength at 0 h and the rate of decrease in breakdown field strength after 1200 h of corrosion. Record the data in Table 1.

[0085] Table 1

[0086]

[0087] Conclusion: The experimental data show that Example 3 achieved better mechanical properties and corrosion resistance among Examples 1-3. Comparative Example 1, without perfluorination modification, had a slight impact on mechanical properties, but the breakdown field strength decreased significantly. Comparative Example 2, by replacing the reinforcing filler with SiO2-MMT composite particles, showed a significant decrease in mechanical properties, but the rate of decrease in breakdown field strength was slightly higher than that of Comparative Example 1, because the breakdown field strength at 0 was lower than that of Comparative Example 1. Comparative Example 3, by increasing the proportion of polyethylene glycol pore-forming agent, resulted in larger pores in the porous particles, making the structure fragile and reducing barrier properties, thus decreasing corrosion resistance. Comparative Example 4, by adjusting the melting temperature of the porous composite particles, showed that under this temperature condition, the pore structure was incomplete, resulting in a significant decrease in tensile strength and corrosion resistance.

[0088] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A corrosion-resistant insulated cable, characterized in that, The corrosion-resistant insulated cable comprises, from the inside out, a conductor, an insulation layer, an armor layer, and a sheath layer; the sheath layer comprises the following raw materials in parts by weight: 70-80 parts polypropylene, 20-30 parts blended polypropylene, 16-20 parts ethylene-propylene-hexene copolymer, 0.01-0.05 parts composite nucleating agent, 0.2-0.3 parts antioxidant, 5-10 parts compatibilizer, 1-3 parts reinforcing filler, and 0.5-1 parts silane-modified zirconium oxide.

2. The corrosion-resistant insulated cable according to claim 1, characterized in that, The blended polypropylene is obtained by blending random copolymer polypropylene and polyolefin elastomer at a mass ratio of 1:0.3~0.5 and granulating. The blending process parameters are: inlet temperature of 180~190℃, outlet temperature of 190~205℃, stirring speed of 120~160r / min, and stirring time of 30~40min.

3. The corrosion-resistant insulated cable according to claim 1, characterized in that, The composite nucleating agent consists of a β-crystalline aromatic amide nucleating agent and an α-crystalline carboxylate nucleating agent in a mass ratio of 1:0.5~0.8; the compatibilizer is maleic anhydride-grafted polypropylene.

4. The corrosion-resistant insulated cable according to claim 1, characterized in that, The preparation steps of the reinforcing filler are as follows: S1: Montmorillonite and ammonia were ultrasonically dispersed in anhydrous ethanol. Tetraethyl orthosilicate and anhydrous ethanol were mixed, and the above montmorillonite mixture was added. After stirring for 6-8 hours, the mixture was filtered and dried to obtain composite particles. The composite particles were placed in deionized water, a dispersant was added, and the mixture was stirred for 2-3 hours. After washing and centrifugation, the particles were dried and pulverized to obtain modified composite particles. The modified composite particles were placed in deionized water, sodium carbonate was added, and the mixture was heated to 75-80℃ and stirred for 2-3 hours. After cooling to 60-70℃, a dispersant was added and the mixture was stirred for 2-3 hours. After filtration and drying, the mixture is ultrasonically dispersed in deionized water for 20-30 minutes. Polyethylene glycol is added and stirred for 10-20 minutes. Gelatin is then added and stirred at 35-45°C for 20-30 minutes. Azobisisobutyronitrile and methyl methacrylate are added, and the mixture is heated to 65-70°C and reacted for 3-4 hours. The temperature is then raised to 80-85°C and reacted for 0.5-1 hour. The mixture is filtered, washed, and dried at 50°C for 20-24 hours. After heating to 80-110°C for 1-3 hours, the mixture is then placed in an ice-water bath to obtain porous modified composite particles. S2: N-vinylformamide, 1H,1H,2H-perfluoro-1-decene, and azobisisobutyronitrile were placed in tetrahydrofuran and reacted at 65-70℃ under a nitrogen atmosphere for 8-10 hours. After filtration and washing, the mixture was dried and placed in ethanol. Sodium hydroxide was added, and the mixture was reacted at 70-75℃ under a nitrogen atmosphere for 48 hours. After rotary evaporation and drying, the mixture was placed in ethanol, hydroiodic acid was added, and the mixture was reacted at -1-0℃ in the dark for 20-24 hours. After filtration and washing, the mixture was placed in ethanol, porous modified composite particles were added, and the mixture was stirred for 2-4 hours. After rotary evaporation and drying, the reinforced filler was obtained.

5. A corrosion-resistant insulated cable according to claim 4, characterized in that, The composite particles in S1 include the following raw material components: by mass, 8-10 parts montmorillonite, 18-20 parts ammonia water, and 45-50 parts tetraethyl orthosilicate; the mass ratio of composite particles to dispersant is 1:0.1-0.

3.

6. A corrosion-resistant insulated cable according to claim 4, characterized in that, The porous modified composite particles in S1 include the following raw material components: by mass, 10-12 parts modified composite particles, 0.8-1 parts sodium carbonate, 1-2 parts dispersant, 2-4 parts polyethylene glycol, 1-1.5 parts gelatin, 0.5-1 parts azobisisobutyronitrile, and 40-50 parts methyl methacrylate.

7. A corrosion-resistant insulated cable according to claim 4, characterized in that, The reinforcing filler in S2 includes the following raw material components: by mass, 0.6~0.9 parts N-vinylformamide, 0.4~0.6 parts 1H,1H,2H-perfluoro-1-decene, 0.02~0.03 parts azobisisobutyronitrile, 0.8~0.9 parts sodium hydroxide, 2.5~2.8 parts hydroiodic acid, and 10~15 parts porous modified composite particles.

8. A corrosion-resistant insulated cable according to claim 1, characterized in that, The insulation layer is made of environmentally friendly polyolefin material; the armor layer is made of galvanized steel wire wound in a spiral structure with a winding angle of 15°~25°.

9. The method for preparing a corrosion-resistant insulated cable according to claim 1, characterized in that, The preparation steps include the following: after sequentially setting an insulation layer and an armor layer on the outside of the conductor, the mixed sheath layer is extruded onto the outer surface of the armor layer to obtain the corrosion-resistant insulated cable.

10. The method for preparing a corrosion-resistant insulated cable according to claim 9, characterized in that, The preparation steps of the sheath layer compound are as follows: polypropylene, blended polypropylene, compatibilizer, reinforcing filler and composite nucleating agent are mixed and stirred at 180~190℃ at 40~60r / min for 6~10min. Then, silane-modified zirconium oxide and ethylene~propylene~hexene copolymer are added and stirred at 180~190℃ at 50~60r / min for 6~8min. Finally, the mixture is extruded and granulated.

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