A corrosion-resistant low-voltage cable and its preparation method

Abstract

The present invention relates to a corrosion-resistant low-voltage cable and a preparation method thereof, belonging to the field of cables, which includes a wire core, an inner semiconductive shielding layer, an insulating layer, an outer semiconductive shielding layer, a metal shielding layer and a sheath layer from inside to outside. The sheath layer is made of a corrosion-resistant sheath material, and the corrosion-resistant sheath material includes the following raw materials in parts by weight: 50-60 parts of polyvinyl chloride, 40-50 parts of flame retardant additive, 25-35 parts of impact modifier, 0.8-1.0 parts of coupling agent, 1.5-2 parts of antioxidant, 25-30 parts of plasticizer, 2-4 parts of crosslinking agent, 8-10 parts of accelerator, 1-3 parts of crosslinking assistant, 10-15 parts of magnesium oxide and 5-10 parts of zinc oxide. The synthesized flame retardant additive contains hydroxyl, DOPO and cinnamamide structures, which improves the flame retardancy and rodent resistance of the cable. The synthesized impact modifier contains a polysiloxane chain and a fluorinated alkane long chain, which improves the impact resistance, waterproofness and high temperature resistance of the cable.

Description

Technical Field

[0001] The present invention belongs to the technical field of cables, and specifically, relates to a corrosion-resistant low-voltage cable and a preparation method thereof. Background Art

[0002] Electric wires and cables are conductors covered with an insulating layer, a shielding layer, a protective layer, etc. for transmitting electric power or signal current and signal voltage. Low-voltage cables are a type of electric wires and cables, and due to their characteristics such as reliable operation, no need for utility poles, no occupation of ground space, and no visual obstruction, they are widely used in low-voltage power distribution systems. Polyvinyl chloride is a commonly used sheath material for electric wires and cables. In actual use, it is found that its high-temperature resistance is insufficient, which is not conducive to the use of cables under high-temperature conditions. And in order to make the cable sheath material have excellent impact strength, acrylate copolymers are usually used to modify it. However, acrylate copolymers have certain hydrophilicity, which is not conducive to the waterproof performance of the cable sheath material; in addition, polyvinyl chloride-based sheath materials do not have halogen-free flame retardant properties, which do not meet the requirements of green environmental protection and halogen-free flame retardant for cable materials.

[0003] The sheath layer made of cable sheath material is located on the outer layer of the cable and is easily gnawed by mice and insects, resulting in a decline in the protective performance of the sheath layer. Adding rodenticides to the cable sheath material produces toxic and harmful substances that are not conducive to environmental protection and human health. Therefore, a suitable method is needed to modify the cable sheath material to improve the comprehensive performance of the cable such as high-temperature resistance, rodent resistance, flame retardancy, and waterproofness by improving the performance of the sheath material. Summary of the Invention

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A corrosion-resistant low-voltage cable includes, from the inside to the outside, a core, an inner semi-conductive shielding layer, an insulating layer, an outer semi-conductive shielding layer, a metal shielding layer, and a sheath layer. The core is located in the innermost layer, and an inner semi-conductive shielding layer is extruded around the outer periphery of the core; an insulating layer is extruded around the outer periphery of the inner semi-conductive shielding layer; an outer semi-conductive shielding layer is extruded around the outer periphery of the insulating layer; a metal shielding layer is arranged around the outer periphery of the outer semi-conductive shielding layer; and a sheath layer is extruded around the outer periphery of the metal shielding layer;

[0006] The core is a plurality of stranded copper wires; both the inner semi-conductive shielding layer and the outer semi-conductive shielding layer are made of ethylene-vinyl acetate copolymer material; the insulating layer is made of cross-linked polyethylene insulating material; the metal shielding layer is an aluminum conductive metal strip wound around the outer semi-conductive shielding layer in a spiral form;

[0007] The sheath layer is made of a corrosion-resistant sheath material, and the corrosion-resistant sheath material comprises the following raw materials in parts by weight: 50-60 parts of polyvinyl chloride, 40-50 parts of flame retardant additive, 25-35 parts of impact modifier, 0.8-1.0 part of coupling agent, 1.5-2 parts of antioxidant, 25-30 parts of plasticizer, 2-4 parts of crosslinking agent, 8-10 parts of accelerator, 1-3 parts of crosslinking aid, 10-15 parts of magnesium oxide, and 5-10 parts of zinc oxide;

[0008] The coupling agent is KH560, the antioxidant is prepared by mixing antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1, the plasticizer is epoxy soybean oil, the crosslinking agent is dicumyl peroxide, the accelerator is accelerator DM, and the crosslinking aid is triallyl isocyanurate;

[0009] The preparation of the corrosion-resistant low-voltage cable comprises the following steps:

[0010] Step S1: Put polyvinyl chloride and impact modifier into a torque rheometer, knead for 10 min, heat up to 90 °C, then add flame retardant additive, coupling agent, antioxidant, plasticizer, magnesium oxide, and zinc oxide into the torque rheometer for kneading. After 25 min, heat up to 130 °C, add crosslinking agent, accelerator, and crosslinking aid, and continue kneading for 10 min to prepare the corrosion-resistant sheath material;

[0011] Step S2: Extrude and deposit the inner semiconductive shielding layer on the outer periphery of the wire core with an extruder, and then extrude and deposit the insulating layer on the outer periphery of the inner semiconductive shielding layer; then extrude and deposit the outer semiconductive shielding layer on the outer periphery of the insulating layer; then wind the aluminum conductive metal tape around the outer periphery of the outer semiconductive shielding layer in a spiral form to obtain a metal shielding layer; finally, extrude and deposit the corrosion-resistant sheath material on the outer periphery of the metal shielding layer, and perform annealing treatment after extrusion to obtain the corrosion-resistant low-voltage cable.

[0012] The preparation of the flame retardant additive comprises the following steps:

[0013] Step A1: Add cinnamic acid and DOPO into a flask, start stirring, heat up to 125-135 °C, and stir and react at a constant temperature for 3-4 h to obtain a reaction product;

[0014] Further, the dosage ratio of cinnamic acid to DOPO is 0.1 mol:0.1 mol;

[0015] During the reaction process of Step A1, DOPO adds to the carbon-carbon double bond of cinnamic acid to obtain the reaction product;

[0016] Step A2: Add 3,4-dihydroxycinnamamide, epichlorohydrin, and tetraethylammonium chloride into a flask. Start stirring and heat up to 75 - 85 °C. Carry out reflux stirring for 1 h. Slowly add the sodium hydroxide solution dropwise, and continue reflux stirring for 2 - 2.5 h. Cool to room temperature. Add benzene to the flask, then slowly add the sodium hydroxide solution dropwise, and carry out reflux stirring for 2 - 2.5 h. Wash with distilled water and perform vacuum distillation to obtain the epoxy product;

[0017] Further, the total amount of 3,4-dihydroxycinnamamide, epichlorohydrin, tetraethylammonium chloride, and sodium hydroxide solution and the amount of benzene used are in the ratio of 0.1 mol: 0.2 mol: 0.001 - 0.002 mol: 85 - 95 mL: 110 - 130 mL; the concentration of the sodium hydroxide solution is 0.25 - 0.30 mol / L, and the volume ratio of the sodium hydroxide solution added in the two times is 1:1;

[0018] During the reaction process of Step A2, under the action of the phase transfer catalyst tetraethylammonium chloride, the phenolic hydroxyl group of 3,4-dihydroxycinnamamide first opens the ring of epichlorohydrin, and the resulting alcohol hydroxyl group and chlorine then form a ring in the sodium hydroxide solution to obtain the epoxy product;

[0019] Step A3: In a nitrogen atmosphere, add the reaction product and toluene into a flask, heat up to 45 °C, add pyridine, start stirring, add the epoxy product to the flask, and stir for 8 - 10 h to obtain the flame retardant additive;

[0020] Further, the amount ratio of the reaction product, toluene, pyridine, and the epoxy product is 0.1 mol: 190 - 200 mL: 0.005 - 0.006 mol: 0.2 mol;

[0021] During the reaction process of Step A3, the carboxyl group of the reaction product opens the ring of the epoxy group of the epoxy product to generate the flame retardant additive;

[0022] The preparation of the impact modifier includes the following steps:

[0023] Step B1: Add vinylpentamethyldisiloxane into DMF, start stirring, and then add 3-chloroperoxybenzoic acid. Stir at room temperature for 4 - 5 h to obtain epoxy product a;

[0024] Further, the amount ratio of vinylpentamethyldisiloxane, DMF, and 3-chloroperoxybenzoic acid is 0.1 mol: 40 - 50 mL: 0.1 mol;

[0025] During the reaction process of Step B1, the carbon-carbon double bond in vinylpentamethyldisiloxane is oxidized to an epoxy group to obtain epoxy product a;

[0026] Step B2: In a nitrogen atmosphere, perfluoropentanoic acid and toluene are added to a flask, the temperature is raised to 45 °C, pyridine is added, stirring is started, and epoxy product a is added to the flask, followed by stirring and reacting for 8 - 10 h to obtain a hydroxyl product;

[0027] Further, the dosage ratio of perfluoropentanoic acid, toluene, pyridine, and epoxy product a is 0.1 mol : 70 - 80 mL : 0.002 - 0.003 mol : 0.1 mol;

[0028] During the reaction process of Step B2, the carboxyl group of perfluoropentanoic acid opens the epoxy ring of epoxy product a to form a hydroxyl product;

[0029] Step B3: The hydroxyl product, pyridine, triethylamine, and dimethyl sulfoxide are added to a flask to obtain mixture 1; methacryloyl chloride is added to dimethyl sulfoxide to obtain mixture 2. In an ice bath at 0 °C, mixture 2 is slowly added dropwise to mixture 1. After the addition is complete, the temperature is raised to 40 °C, and the mixture is stirred and reacted at a constant temperature for 8 - 10 h, followed by vacuum distillation to obtain a fluorosilicon product;

[0030] Further, the dosage ratio of the hydroxyl product, pyridine, triethylamine, and dimethyl sulfoxide is 0.1 mol : 0.01 - 0.015 mol : 0.1 mol : 80 - 90 mL; the dosage ratio of methacryloyl chloride and dimethyl sulfoxide is 0.1 mol : 20 - 30 mL; the dosage ratio of mixture 1 and mixture 2 is 85 - 95 mL : 25 - 35 mL;

[0031] During the reaction process of Step B3, the hydroxyl group of the hydroxyl product reacts with methacryloyl chloride to form a fluorosilicon product containing a terminal double bond;

[0032] Step B4: Methyl methacrylate, butyl acrylate, the fluorosilicon product, 2 - hydroxyethyl methacrylate, and acrylic acid are added to a flask, stirring is started, and then benzoyl peroxide, xylene, and butyl acetate are added. The mixture is stirred and reacted at 100 °C for 7 - 9 h to obtain an impact modifier;

[0033] Further, the dosage ratio of methyl methacrylate, butyl acrylate, the fluorosilicon product, 2 - hydroxyethyl methacrylate, acrylic acid, benzoyl peroxide, xylene, and butyl acetate is 45 g : 30 g : 10 g : 10 g : 5 g : 1 g : 150 mL : 100 mL;

[0034] During the reaction process of Step B4, methyl methacrylate, butyl acrylate, the fluorosilicon product, 2 - hydroxyethyl methacrylate, and acrylic acid are polymerized under the initiation of benzoyl peroxide to obtain an impact modifier;

[0035] Advantages of the present invention: The present invention discloses a corrosion-resistant low-voltage cable, which includes a conductor core, an inner semiconductive shielding layer, an insulating layer, an outer semiconductive shielding layer, a metal shielding layer and a sheath layer from inside to outside. The sheath layer comprises the following raw materials: polyvinyl chloride, flame retardant additive, impact modifier, coupling agent, antioxidant, plasticizer, crosslinking agent, accelerator, crosslinking aid, magnesium oxide and zinc oxide. Polyvinyl chloride has excellent acid and alkali corrosion resistance, meeting the use requirements of the corrosion-resistant low-voltage cable. The flame retardant additive has a DOPO-based backbone, and active hydroxyl groups and cinnamamide structures are introduced therein; the active hydroxyl groups crosslink with the carboxyl and hydroxyl functional groups in the impact modifier, and the impact modifier has good dispersibility in polyvinyl chloride with a relatively large polarity. As the impact modifier is dispersed in the matrix, the flame retardant additive is evenly dispersed in the matrix, avoiding uneven dispersion or migration failure of small molecules of DOPO and cinnamamide in the matrix; the DOPO structure can cause the polymer surface to dehydrate and degrade to form a carbon layer during matrix combustion, and at the same time, the generated phosphorus-containing derivatives cover the polymer surface, isolating combustible gases and blocking heat transfer, forming a physical shield, playing a role in flame retardancy and fire prevention, making the cable have a halogen-free flame retardant characteristic; adding cinnamamide to the matrix not only does not produce toxic substances, odors harmful to the human body and pollute the environment, but also can repel mice for a long time, preventing mice from gnawing on the sheath material and causing the cable sheath to lose its protective effect. Therefore, the flame retardant additive gives the cable good halogen-free flame retardancy and mouse-proof property.

[0036] The synthesized impact modifier has a polysiloxane chain and a fluorinated alkane long chain introduced into the acrylate copolymer; the acrylate copolymer can significantly improve the impact strength of polyvinyl chloride, and the carboxyl and hydroxyl groups in the acrylate copolymer crosslink with the hydroxyl groups of the flame retardant additive, increasing the crosslinking network density of the system. Cooperating with the fluorinated alkane long chain with strong hydrophobicity, the waterproof property of the sheath material is enhanced, thus significantly improving the waterproof property of the cable; the polysiloxane chain has relatively high bond energies of Si-O-Si bonds and Si-C bonds, and requires high energy to break, improving the thermal stability of the cable sheath material, enabling the cable to have good use performance under high-temperature conditions, and improving the high-temperature resistance of the cable. Therefore, adding the synthesized impact modifier improves the waterproof property and high-temperature resistance of the cable. Brief Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a schematic structural diagram of a corrosion-resistant low-voltage cable of the present invention.

[0039] In the accompanying drawings, the list of components represented by each label is as follows:

[0040] Ⅰ. Core; Ⅱ. Inner semiconductive shielding layer; Ⅲ. Insulating layer; Ⅳ. Outer semiconductive shielding layer; Ⅴ. Metal shielding layer; Ⅵ. Sheath layer. Specific embodiments

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0042] Embodiment 1

[0043] A flame retardant aid is prepared by the following steps:

[0044] Step A1: Add cinnamic acid and DOPO to a flask, start stirring, heat up to 125 °C, and stir and react at a constant temperature for 3 h to obtain a reaction product; the dosage ratio of cinnamic acid to DOPO is 0.1 mol: 0.1 mol;

[0045] Step A2: Add 3,4-dihydroxycinnamamide, epichlorohydrin, and tetraethylammonium chloride to the flask, start stirring, heat up to 75 °C, reflux and stir for 1 h, slowly add sodium hydroxide solution dropwise, continue reflux and stir for 2 h, cool to room temperature, add benzene to the flask, then slowly add sodium hydroxide solution dropwise, reflux and stir for 2 h, wash with distilled water and distill under reduced pressure to obtain an epoxy product; the total amount of 3,4-dihydroxycinnamamide, epichlorohydrin, tetraethylammonium chloride, and sodium hydroxide solution and the dosage ratio of benzene is 0.1 mol: 0.2 mol: 0.001 mol: 85 mL: 110 mL; the concentration of the sodium hydroxide solution is 0.25 mol / L, and the volume ratio of the sodium hydroxide solution added twice is 1:1;

[0046] Step A3: In a nitrogen atmosphere, add the reaction product and toluene to the flask, heat up to 45 °C, add pyridine, start stirring, add the epoxy product to the flask, and stir and react for 8 h to obtain the flame retardant aid; the dosage ratio of the reaction product, toluene, pyridine, and the epoxy product is 0.1 mol: 190 mL: 0.005 mol: 0.2 mol.

[0047] Embodiment 2

[0048] A flame retardant aid is prepared by the following steps:

[0049] Step A1: Add cinnamic acid and DOPO into a flask, start stirring, heat up to 130 °C, and carry out a constant-temperature stirring reaction for 3.5 h to obtain the reaction product; the dosage ratio of cinnamic acid to DOPO is 0.1 mol: 0.1 mol;

[0050] Step A2: Add 3,4-dihydroxycinnamamide, epichlorohydrin, and tetraethylammonium chloride into the flask, start stirring, heat up to 80 °C, carry out a reflux stirring reaction for 1 h, slowly add a sodium hydroxide solution dropwise, continue the reflux stirring reaction for 2.2 h, cool to room temperature, add benzene to the flask, then slowly add the sodium hydroxide solution dropwise, carry out a reflux stirring reaction for 2.2 h, wash with distilled water and carry out vacuum distillation to obtain the epoxy product; the total amount of 3,4-dihydroxycinnamamide, epichlorohydrin, tetraethylammonium chloride, and sodium hydroxide solution and the dosage of benzene are in the ratio of 0.1 mol: 0.2 mol: 0.0015 mol: 90 mL: 120 mL; the concentration of the sodium hydroxide solution is 0.27 mol / L, and the volume ratio of the sodium hydroxide solution added successively twice is 1:1;

[0051] Step A3: Under a nitrogen atmosphere, add the reaction product and toluene into the flask, heat up to 45 °C, add pyridine, start stirring, add the epoxy product into the flask, and carry out a stirring reaction for 9 h to obtain the flame retardant aid; the dosage ratio of the reaction product, toluene, pyridine, and epoxy product is 0.1 mol: 195 mL: 0.005 mol: 0.2 mol.

[0052] Example 3

[0053] A flame retardant aid is prepared through the following steps:

[0054] Step A1: Add cinnamic acid and DOPO into a flask, start stirring, heat up to 135 °C, and carry out a constant-temperature stirring reaction for 4 h to obtain the reaction product; the dosage ratio of cinnamic acid to DOPO is 0.1 mol: 0.1 mol;

[0055] Step A2: Add 3,4-dihydroxycinnamamide, epichlorohydrin, and tetraethylammonium chloride into the flask, start stirring, heat up to 85 °C, carry out a reflux stirring reaction for 1 h, slowly add a sodium hydroxide solution dropwise, continue the reflux stirring reaction for 2.5 h, cool to room temperature, add benzene to the flask, then slowly add the sodium hydroxide solution dropwise, carry out a reflux stirring reaction for 2.5 h, wash with distilled water and carry out vacuum distillation to obtain the epoxy product; the total amount of 3,4-dihydroxycinnamamide, epichlorohydrin, tetraethylammonium chloride, and sodium hydroxide solution and the dosage of benzene are in the ratio of 0.1 mol: 0.2 mol: 0.002 mol: 95 mL: 130 mL; the concentration of the sodium hydroxide solution is 0.30 mol / L, and the volume ratio of the sodium hydroxide solution added successively twice is 1:1;

[0056] Step A3: In a nitrogen atmosphere, add the reaction product and toluene into a flask, heat up to 45°C, add pyridine, start stirring, add the epoxy product into the flask, and stir and react for 10 h to obtain the flame retardant additive; the dosage ratio of the reaction product, toluene, pyridine and the epoxy product is 0.1 mol: 200 mL: 0.006 mol: 0.2 mol.

[0057] Example 4

[0058] An impact modifier is prepared through the following steps:

[0059] Step B1: Add vinylpentamethyldisiloxane into DMF, start stirring, then add 3-chloroperoxybenzoic acid, and stir and react at room temperature for 4 h to obtain epoxy product a; the dosage ratio of vinylpentamethyldisiloxane, DMF and 3-chloroperoxybenzoic acid is 0.1 mol: 40 mL: 0.1 mol;

[0060] Step B2: In a nitrogen atmosphere, add perfluoropentanoic acid and toluene into a flask, heat up to 45°C, add pyridine, start stirring, add epoxy product a into the flask, and stir and react for 8 h to obtain the hydroxyl product; the dosage ratio of perfluoropentanoic acid, toluene, pyridine and epoxy product a is 0.1 mol: 70 mL: 0.002 mol: 0.1 mol;

[0061] Step B3: Add the hydroxyl product, pyridine, triethylamine and dimethyl sulfoxide into a flask to obtain mixture 1; add methacryloyl chloride into dimethyl sulfoxide to obtain mixture 2. In an ice-water bath at 0°C, slowly dropwise add mixture 2 into mixture 1. After the dropping is completed, heat up to 40°C, keep stirring and reacting for 8 h, and perform reduced pressure distillation to obtain the fluorosilicon product; the dosage ratio of the hydroxyl product, pyridine, triethylamine and dimethyl sulfoxide is 0.1 mol: 0.01 mol: 0.1 mol: 80 mL; the dosage ratio of methacryloyl chloride and dimethyl sulfoxide is 0.1 mol: 20 mL; the dosage ratio of mixture 1 and mixture 2 is 85 mL: 25 mL;

[0062] Step B4: Add methyl methacrylate, butyl acrylate, fluorosilicon product, 2-hydroxyethyl methacrylate and acrylic acid into a flask, start stirring, then add benzoyl peroxide, xylene and butyl acetate, and stir and react at 100°C for 7 h to obtain the impact modifier; the dosage ratio of methyl methacrylate, butyl acrylate, fluorosilicon product, 2-hydroxyethyl methacrylate, acrylic acid, benzoyl peroxide, xylene and butyl acetate is 45 g: 30 g: 10 g: 10 g: 5 g: 1 g: 150 mL: 100 mL.

[0063] Example 5

[0064] An impact modifier is prepared through the following steps:

[0065] Step B1: Add vinyl pentamethyldisiloxane into DMF, start stirring, then add 3-chloroperoxybenzoic acid, and stir and react at room temperature for 4.5 h to obtain epoxy product a; the dosage ratio of vinyl pentamethyldisiloxane, DMF and 3-chloroperoxybenzoic acid is 0.1 mol: 45 mL: 0.1 mol;

[0066] Step B2: In a nitrogen atmosphere, add perfluoropentanoic acid and toluene into a flask, heat up to 45 °C, add pyridine, start stirring, add epoxy product a into the flask, and stir and react for 9 h to obtain a hydroxyl product; the dosage ratio of perfluoropentanoic acid, toluene, pyridine and epoxy product a is 0.1 mol: 75 mL: 0.002 mol: 0.1 mol;

[0067] Step B3: Add the hydroxyl product, pyridine, triethylamine and dimethyl sulfoxide into a flask to obtain mixture 1; add methacryloyl chloride into dimethyl sulfoxide to obtain mixture 2. In an ice-water bath at 0 °C, slowly dropwise add mixture 2 into mixture 1. After the addition is completed, heat up to 40 °C and stir and react at a constant temperature for 9 h, then carry out vacuum distillation to obtain the fluorosilicon product; the dosage ratio of the hydroxyl product, pyridine, triethylamine and dimethyl sulfoxide is 0.1 mol: 0.013 mol: 0.1 mol: 85 mL; the dosage ratio of methacryloyl chloride and dimethyl sulfoxide is 0.1 mol: 25 mL; the dosage ratio of mixture 1 and mixture 2 is 90 mL: 30 mL;

[0068] Step B4: Add methyl methacrylate, butyl acrylate, the fluorosilicon product, 2-hydroxyethyl methacrylate and acrylic acid into a flask, start stirring, then add benzoyl peroxide, xylene and butyl acetate, and stir and react at 100 °C for 8 h to obtain an impact modifier; the dosage ratio of methyl methacrylate, butyl acrylate, the fluorosilicon product, 2-hydroxyethyl methacrylate, acrylic acid, benzoyl peroxide, xylene and butyl acetate is 45 g: 30 g: 10 g: 10 g: 5 g: 1 g: 150 mL: 100 mL.

[0069] Example 6

[0070] An impact modifier is prepared through the following steps:

[0071] Step B1: Add vinyl pentamethyldisiloxane into DMF, start stirring, then add 3-chloroperoxybenzoic acid, and stir and react at room temperature for 5 h to obtain epoxy product a; the dosage ratio of vinyl pentamethyldisiloxane, DMF and 3-chloroperoxybenzoic acid is 0.1 mol: 50 mL: 0.1 mol;

[0072] Step B2: In a nitrogen atmosphere, perfluoropentanoic acid and toluene are added to a flask, heated to 45 °C, pyridine is added, stirring is started, and epoxy product a is added to the flask, followed by stirring and reacting for 10 h to obtain a hydroxyl product; the dosage ratio of perfluoropentanoic acid, toluene, pyridine, and epoxy product a is 0.1 mol: 80 mL: 0.003 mol: 0.1 mol;

[0073] Step B3: The hydroxyl product, pyridine, triethylamine, and dimethyl sulfoxide are added to a flask to obtain mixture 1; methacryloyl chloride is added to dimethyl sulfoxide to obtain mixture 2. In an ice bath at 0 °C, mixture 2 is slowly added dropwise to mixture 1. After the addition is complete, the temperature is raised to 40 °C, and the mixture is stirred and reacted at a constant temperature for 10 h, followed by distillation under reduced pressure to obtain a fluorosilicon product; the dosage ratio of the hydroxyl product, pyridine, triethylamine, and dimethyl sulfoxide is 0.1 mol: 0.015 mol: 0.1 mol: 90 mL; the dosage ratio of methacryloyl chloride and dimethyl sulfoxide is 0.1 mol: 30 mL; the dosage ratio of mixture 1 and mixture 2 is 95 mL: 35 mL;

[0074] Step B4: Methyl methacrylate, butyl acrylate, the fluorosilicon product, 2-hydroxyethyl methacrylate, and acrylic acid are added to a flask, stirring is started, and then benzoyl peroxide, xylene, and butyl acetate are added. The mixture is stirred and reacted at 100 °C for 9 h to obtain an impact modifier; the dosage ratio of methyl methacrylate, butyl acrylate, the fluorosilicon product, 2-hydroxyethyl methacrylate, acrylic acid, benzoyl peroxide, xylene, and butyl acetate is 45 g: 30 g: 10 g: 10 g: 5 g: 1 g: 150 mL: 100 mL.

[0075] Example 7

[0076] As Figure 1 shown, the corrosion-resistant low-voltage cable includes, from the inside to the outside, a core I, an inner semiconductive shielding layer II, an insulating layer III, an outer semiconductive shielding layer IV, a metal shielding layer V, and a sheath layer VI. The core I is located in the innermost layer, and an inner semiconductive shielding layer II is extruded around the outer periphery of the core I; an insulating layer III is extruded around the outer periphery of the inner semiconductive shielding layer II; an outer semiconductive shielding layer IV is extruded around the outer periphery of the insulating layer III; a metal shielding layer V is provided around the outer periphery of the outer semiconductive shielding layer IV; a sheath layer VI is extruded around the outer periphery of the metal shielding layer V; the core I is a plurality of stranded copper wires, the inner semiconductive shielding layer II and the outer semiconductive shielding layer IV are both made of ethylene-vinyl acetate copolymer material, the insulating layer III is made of cross-linked polyethylene insulating material, and the metal shielding layer V is an aluminum conductive metal strip wound around the outer semiconductive shielding layer IV in a spiral form;

[0077] The sheath layer VI is made of a corrosion-resistant sheath material, and the corrosion-resistant sheath material comprises the following raw materials in parts by weight: 50 parts of polyvinyl chloride, 40 parts of a flame retardant aid, 25 parts of an impact modifier, 0.8 part of a coupling agent, 1.5 parts of an antioxidant, 25 parts of a plasticizer, 2 parts of a crosslinking agent, 8 parts of an accelerator, 1 part of a crosslinking aid, 10 parts of magnesium oxide, and 5 parts of zinc oxide; the coupling agent is KH560, the antioxidant is prepared by mixing antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1, the plasticizer is epoxy soybean oil, the crosslinking agent is dicumyl peroxide, the accelerator is accelerator DM, and the crosslinking aid is triallyl isocyanurate;

[0078] The preparation of the corrosion-resistant low-voltage cable comprises the following steps:

[0079] Step S1: Put the polyvinyl chloride and the impact modifier obtained in Example 4 into a torque rheometer, knead for 10 min, raise the temperature to 90 °C, and then add the flame retardant aid, coupling agent, antioxidant, plasticizer, magnesium oxide, and zinc oxide obtained in Example 1 into the torque rheometer for kneading. After 25 min, raise the temperature to 130 °C, add the crosslinking agent, accelerator, and crosslinking aid, and continue kneading for 10 min to prepare the corrosion-resistant sheath material;

[0080] Step S2: Extrude and deposit the inner semi-conductive shielding layer on the outer periphery of the wire core with an extruder, and then extrude and deposit the insulating layer on the outer periphery of the inner semi-conductive shielding layer; then extrude and deposit the outer semi-conductive shielding layer on the outer periphery of the insulating layer; then wind the aluminum conductive metal tape around the outer periphery of the outer semi-conductive shielding layer in a spiral form to obtain a metal shielding layer; finally, extrude and deposit the corrosion-resistant sheath material on the outer periphery of the metal shielding layer, and perform annealing treatment after extrusion to obtain the corrosion-resistant low-voltage cable.

[0081] Example 8

[0082] As Figure 1 shown, the corrosion-resistant low-voltage cable comprises a wire core I, an inner semi-conductive shielding layer II, an insulating layer III, an outer semi-conductive shielding layer IV, a metal shielding layer V, and a sheath layer VI from the inside out. The wire core I is located in the innermost layer, and the inner semi-conductive shielding layer II is extruded and wrapped around the outer periphery of the wire core I; the insulating layer III is extruded and wrapped around the outer periphery of the inner semi-conductive shielding layer II; the outer semi-conductive shielding layer IV is extruded and wrapped around the outer periphery of the insulating layer III; the metal shielding layer V is arranged on the outer periphery of the outer semi-conductive shielding layer IV; the sheath layer VI is extruded and wrapped around the outer periphery of the metal shielding layer V; the wire core I is a plurality of stranded copper wires, the inner semi-conductive shielding layer II and the outer semi-conductive shielding layer IV are both made of ethylene-vinyl acetate copolymer material, the insulating layer III is made of crosslinked polyethylene insulating material, and the metal shielding layer V is obtained by winding the aluminum conductive metal tape around the outer semi-conductive shielding layer IV in a spiral form;

[0083] The sheath layer VI is made of a corrosion-resistant sheath material, and the corrosion-resistant sheath material includes the following raw materials in parts by weight: 55 parts of polyvinyl chloride, 45 parts of flame retardant additive, 30 parts of impact modifier, 0.9 part of coupling agent, 1.7 parts of antioxidant, 27 parts of plasticizer, 3 parts of crosslinking agent, 9 parts of accelerator, 2 parts of crosslinking aid, 12 parts of magnesium oxide and 7 parts of zinc oxide; the coupling agent is KH560, the antioxidant is prepared by mixing antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1, the plasticizer is epoxy soybean oil, the crosslinking agent is dicumyl peroxide, the accelerator is accelerator DM, and the crosslinking aid is triallyl isocyanurate;

[0084] The preparation of the corrosion-resistant low-voltage cable includes the following steps:

[0085] Step S1: Put polyvinyl chloride and the impact modifier obtained in Example 5 into a torque rheometer, knead for 10 min, heat up to 90 °C, and then add the flame retardant additive, coupling agent, antioxidant, plasticizer, magnesium oxide and zinc oxide obtained in Example 2 into the torque rheometer for kneading. After 25 min, heat up to 130 °C, add the crosslinking agent, accelerator and crosslinking aid, and continue kneading for 10 min to make the corrosion-resistant sheath material;

[0086] Step S2: Extrude and deposit the inner semi-conductive shielding layer on the outer periphery of the wire core with an extruder, and then extrude and deposit the insulating layer on the outer periphery of the inner semi-conductive shielding layer; then extrude and deposit the outer semi-conductive shielding layer on the outer periphery of the insulating layer; then wind the aluminum conductive metal tape around the outer periphery of the outer semi-conductive shielding layer in a spiral form to obtain a metal shielding layer; finally, extrude and deposit the corrosion-resistant sheath material on the outer periphery of the metal shielding layer, and perform annealing treatment after extrusion to obtain the corrosion-resistant low-voltage cable.

[0087] Example 9

[0088] As Figure 1 shown, the corrosion-resistant low-voltage cable includes a wire core I, an inner semi-conductive shielding layer II, an insulating layer III, an outer semi-conductive shielding layer IV, a metal shielding layer V and a sheath layer VI from the inside to the outside. The wire core I is located in the innermost layer, and the inner semi-conductive shielding layer II is extruded and wrapped around the outer periphery of the wire core I; the insulating layer III is extruded and wrapped around the outer periphery of the inner semi-conductive shielding layer II; the outer semi-conductive shielding layer IV is extruded and wrapped around the outer periphery of the insulating layer III; the metal shielding layer V is arranged on the outer periphery of the outer semi-conductive shielding layer IV; the sheath layer VI is extruded and wrapped around the outer periphery of the metal shielding layer V; the wire core I is a multi-strand stranded copper wire, the inner semi-conductive shielding layer II and the outer semi-conductive shielding layer IV are both made of ethylene-vinyl acetate copolymer material, the insulating layer III is made of cross-linked polyethylene insulating material, and the metal shielding layer V is obtained by winding the aluminum conductive metal tape around the outer semi-conductive shielding layer IV in a spiral form;

[0089] The sheath layer VI is made of a corrosion-resistant sheath material, and the corrosion-resistant sheath material includes the following raw materials in parts by weight: 60 parts of polyvinyl chloride, 50 parts of flame retardant, 35 parts of impact modifier, 1.0 part of coupling agent, 2 parts of antioxidant, 30 parts of plasticizer, 4 parts of crosslinking agent, 10 parts of accelerator, 3 parts of crosslinking aid, 15 parts of magnesium oxide, and 10 parts of zinc oxide; the coupling agent is KH560, the antioxidant is prepared by mixing antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1, the plasticizer is epoxy soybean oil, the crosslinking agent is dicumyl peroxide, the accelerator is accelerator DM, and the crosslinking aid is triallyl isocyanurate;

[0090] The preparation of the corrosion-resistant low-voltage cable includes the following steps:

[0091] Step S1: Put polyvinyl chloride and the impact modifier obtained in Example 6 into a torque rheometer, knead for 10 min, heat up to 90 °C, and then add the flame retardant, coupling agent, antioxidant, plasticizer, magnesium oxide, and zinc oxide obtained in Example 3 to the torque rheometer for kneading. After 25 min, heat up to 130 °C, add the crosslinking agent, accelerator, and crosslinking aid, and continue kneading for 10 min to make the corrosion-resistant sheath material;

[0092] Step S2: Extrude and deposit the inner semi-conductive shielding layer on the outer periphery of the wire core with an extruder, and then extrude and deposit the insulating layer on the outer periphery of the inner semi-conductive shielding layer; then extrude and deposit the outer semi-conductive shielding layer on the outer periphery of the insulating layer; then wind the aluminum conductive metal tape around the outer periphery of the outer semi-conductive shielding layer in a spiral form to obtain a metal shielding layer; finally, extrude and deposit the corrosion-resistant sheath material on the outer periphery of the metal shielding layer, and perform annealing treatment after extrusion to obtain the corrosion-resistant low-voltage cable.

[0093] Comparative Example 1

[0094] Compared with Example 9, replace the flame retardant with DOPO, and the rest is exactly the same as Example 9 to prepare a corrosion-resistant low-voltage cable.

[0095] Comparative Example 2

[0096] Compared with Example 9, replace the impact modifier with an acrylate copolymer, and the rest is exactly the same as Example 9 to prepare a corrosion-resistant low-voltage cable; the preparation process of the acrylate copolymer is as follows: Put methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate, and acrylic acid into a flask, start stirring, and then add benzoyl peroxide, xylene, and butyl acetate, and stir and react at 100 °C for 9 h to obtain an acrylate copolymer; the dosage ratio of methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate, acrylic acid, benzoyl peroxide, xylene, and butyl acetate is 45 g: 40 g: 10 g: 5 g: 1 g: 150 mL: 100 mL.

[0097] The corrosion-resistant low-voltage cable prepared by the present invention is further subjected to effect detection, and the detection results are as follows.

[0098] To test the corrosion-resistant low-voltage cable prepared by the present invention, performance tests were carried out on the sheath materials of the low-voltage cables obtained in Examples 7-9 and Comparative Examples 1-2. According to GB / T2951.32-2008 "General test methods for insulating and sheathing materials of cables and optical cables", the experiment of determining the thermal stability time at 200 °C was carried out; according to GB / T2406.1-2008 "Plastics - Determination of burning behavior by the oxygen index method", the oxygen index was tested; according to GB / T34016-2017 "General rules for anti-rat and anti-termite electric wires and cables", the anti-rat performance was tested; for the waterproof performance test method: take the corrosion-resistant low-voltage cable samples obtained in Examples 7-9 and Comparative Examples 1-2 with a weight of 150.0 g and immerse them in water (water temperature 15 °C). The two ends of the samples are sealed, and 300 mm of the length extends out of the water surface. After soaking for one week, the weight after soaking is measured, and after removing the sheath layer after soaking, observe whether there is moisture on the outer surface; the impact strength was tested using an impact testing machine in accordance with GB / T1843-2008 "Determination of the impact strength of plastics by the cantilever beam method"; the results are recorded in Table 1;

[0099] Table 1:

[0100]

[0101]

[0102] According to the data in Table 1, the sheath material of the corrosion-resistant low-voltage cable prepared by the present invention has good high-temperature resistance, flame retardancy, waterproofness, anti-rat property and impact strength; compared with Example 9 in Comparative Example 1, by using a flame retardant assistant introducing active hydroxyl groups and cinnamamide in the DOPO skeleton, while the sheath material has good flame retardancy, it also has good anti-rat property, thus improving the flame retardancy and anti-rat property of the corrosion-resistant cable. The cross-linking of the active hydroxyl groups and the impact modifier is also beneficial to the improvement of the waterproofness of the cable; compared with Example 9 in Comparative Example 2, by using an acrylate copolymer containing polysiloxane and fluorinated alkane long chains as the impact modifier, the waterproofness and high-temperature resistance of the sheath material are improved, thus improving the waterproofness and high-temperature resistance of the cable.

[0103] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by the claims of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A corrosion-resistant low-voltage cable, characterized in that: From the inside out, it includes a conductor core Ⅰ, an inner semiconductive shielding layer Ⅱ, an insulating layer Ⅲ, an outer semiconductive shielding layer Ⅳ, a metallic shielding layer Ⅴ, and a sheath layer Ⅵ. The conductor core Ⅰ is located in the innermost layer, and the inner semiconductive shielding layer Ⅱ is extruded around the outer periphery of the conductor core Ⅰ; the insulating layer Ⅲ is extruded around the outer periphery of the inner semiconductive shielding layer Ⅱ; the outer semiconductive shielding layer Ⅳ is extruded around the outer periphery of the insulating layer Ⅲ; the metallic shielding layer Ⅴ is arranged around the outer periphery of the outer semiconductive shielding layer Ⅳ; the sheath layer Ⅵ is extruded around the outer periphery of the metallic shielding layer Ⅴ; the sheath layer Ⅵ is made of a corrosion-resistant sheath material, and the corrosion-resistant sheath material includes the following raw materials in parts by weight: 50 - 60 parts of polyvinyl chloride, 40 - 50 parts of flame retardant additive, 25 - 35 parts of impact modifier, 0.8 - 1.0 part of coupling agent, 1.5 - 2 parts of antioxidant, 25 - 30 parts of plasticizer, 2 - 4 parts of crosslinking agent, 8 - 10 parts of accelerator, 1 - 3 parts of crosslinking assistant, 10 - 15 parts of magnesium oxide, and 5 - 10 parts of zinc oxide; both the inner semiconductive shielding layer Ⅱ and the outer semiconductive shielding layer Ⅳ are made of ethylene-vinyl acetate copolymer material, the insulating layer Ⅲ is made of crosslinked polyethylene insulating material, and the metallic shielding layer Ⅴ is obtained by winding an aluminum conductive metal tape in a spiral form around the outer semiconductive shielding layer Ⅳ; The preparation of the flame retardant additive includes the following steps: Step A1: Add cinnamic acid and DOPO into a flask, start stirring, heat up to 125 - 135 °C, and stir and react at a constant temperature for 3 - 4 h to obtain a reaction product; in Step A1, the dosage ratio of cinnamic acid to DOPO is 0.1 mol:0.1 mol; Step A2: Add 3,4-dihydroxycinnamamide, epichlorohydrin, and tetraethylammonium chloride into the flask, start stirring, heat up to 75 - 85 °C, reflux and stir for 1 h, slowly dropwise add sodium hydroxide solution, continue reflux and stir for 2 - 2.5 h, cool to room temperature, add benzene into the flask, then slowly dropwise add sodium hydroxide solution, reflux and stir for 2 - 2.5 h, wash with distilled water and distill under reduced pressure to obtain epoxy product 2; in Step A2, the total amount of 3,4-dihydroxycinnamamide, epichlorohydrin, tetraethylammonium chloride, and sodium hydroxide solution and the dosage ratio of benzene is 0.1 mol:0.2 mol:0.001 - 0.002 mol:85 - 95 mL:110 - 130 mL; the concentration of the sodium hydroxide solution is 0.25 - 0.30 mol / L, and the volume ratio of the sodium hydroxide solution added twice is 1:1; Step A3: In a nitrogen atmosphere, add the reaction product and toluene into the flask, heat up to 45 °C, add pyridine, start stirring, add the epoxy product into the flask, and stir and react for 8 - 10 h to obtain the flame retardant additive; in Step A3, the dosage ratio of the reaction product, toluene, pyridine, and the epoxy product is 0.1 mol:190 - 200 mL:0.005 - 0.006 mol:0.2 mol; Step B1: Add vinylpentamethyldisiloxane into DMF, start stirring, and then add 3-chloroperoxybenzoic acid, and stir and react at room temperature for 4 - 5 h to obtain epoxy product a; Step B2: In a nitrogen atmosphere, perfluoropentanoic acid and toluene are added to a flask, the temperature is raised to 45 °C, pyridine is added, stirring is started, and epoxy product a is added to the flask, followed by stirring and reacting for 8 - 10 h to obtain a hydroxyl product; Step B3: The hydroxyl product, pyridine, triethylamine, and dimethyl sulfoxide are added to a flask to obtain mixture 1; methacryloyl chloride is added to dimethyl sulfoxide to obtain mixture 2. In an ice bath at 0 °C, mixture 2 is slowly added dropwise to mixture 1. After the addition is complete, the temperature is raised to 40 °C, and the mixture is stirred and reacted at a constant temperature for 8 - 10 h, followed by distillation under reduced pressure to obtain a fluorosilicon product; Step B4: Methyl methacrylate, butyl acrylate, the fluorosilicon product, 2-hydroxyethyl methacrylate, and acrylic acid are added to a flask, stirring is started, and then benzoyl peroxide, xylene, and butyl acetate are added. The mixture is stirred and reacted at 100 °C for 7 - 9 h to obtain an impact modifier; In Step B1, the dosage ratio of vinyl pentamethyldisiloxane, DMF, and 3-chloroperoxybenzoic acid is 0.1 mol : 40 - 50 mL : 0.1 mol; in Step B2, the dosage ratio of perfluoropentanoic acid, toluene, pyridine, and epoxy product a is 0.1 mol : 70 - 80 mL : 0.002 - 0.003 mol : 0.1 mol; In Step B3, the dosage ratio of the hydroxyl product, pyridine, triethylamine, and dimethyl sulfoxide is 0.1 mol : 0.01 - 0.015 mol : 0.1 mol : 80 - 90 mL; the dosage ratio of methacryloyl chloride and dimethyl sulfoxide is 0.1 mol : 20 - 30 mL; the dosage ratio of mixture 1 and mixture 2 is 85 - 95 mL : 25 - 35 mL; In Step B4, the dosage ratio of methyl methacrylate, butyl acrylate, the fluorosilicon product, 2-hydroxyethyl methacrylate, acrylic acid, benzoyl peroxide, xylene, and butyl acetate is 45 g : 30 g : 10 g : 10 g : 5 g : 1 g : 150 mL : 100 mL.

2. The corrosion-resistant low-voltage cable according to claim 1, wherein: The core I is multiple stranded copper wires, the coupling agent is KH560, the antioxidant is prepared by mixing antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1, the plasticizer is epoxy soybean oil, the crosslinking agent is dicumyl peroxide, the accelerator is accelerator DM, and the crosslinking aid is triallyl isocyanurate.

3. The preparation method of a corrosion-resistant low-voltage cable according to claim 1, characterized in that: It includes the following steps: Step S1: Polyvinyl chloride and the impact modifier are put into a torque rheometer and kneaded for 10 min. The temperature is raised to 90 °C, and then a flame retardant aid, coupling agent, antioxidant, plasticizer, magnesium oxide, and zinc oxide are added to the torque rheometer for kneading. After 25 min, the temperature is raised to 130 °C, and a crosslinking agent, accelerator, and crosslinking aid are added, followed by continued kneading for 10 min to prepare a corrosion-resistant sheath material; Step S2: Extrude and deposit the inner semi-conductive shielding layer on the outer periphery of the wire core with an extruder, and then extrude and deposit the insulating layer on the outer periphery of the inner semi-conductive shielding layer; then extrude and deposit the outer semi-conductive shielding layer on the outer periphery of the insulating layer; then wind an aluminum conductive metal tape around the outer periphery of the outer semi-conductive shielding layer in a spiral form to obtain a metal shielding layer; finally, extrude and deposit a corrosion-resistant sheath material on the outer periphery of the metal shielding layer, and perform annealing treatment after extrusion to obtain a corrosion-resistant low-voltage cable.

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