CN118571545A - High-conductivity flame-retardant cable and production process thereof - Google Patents

Abstract

The present invention relates to the field of cable technology, and discloses a high-conductivity flame-retardant cable and a production process thereof. The cable produced in the present invention is provided with a conductor, an anti-oxidation layer, a shielding layer, an insulating layer and an outer sheath layer; the conductor is a copper conductor, the anti-oxidation layer is formed by extruding and coating an anti-oxidation material on the surface of the copper conductor, the shielding layer is formed by shielding an aluminum-plastic composite tape coated on the surface of the anti-oxidation layer, the insulating layer is formed by coating a polyvinyl chloride on the surface of the shielding layer, and the outer sheath layer is formed by extruding a sheath material and coating it outside the insulating layer; wherein, the addition of the anti-oxidation layer effectively reduces the decrease in conductivity caused by oxidation of the conductor, and improves the conductivity of the cable; the composite flame retardant added to the sheath material used for the outer sheath layer improves the flame retardant performance of the cable.

Description

A high-conductivity flame-retardant cable and its production process

Technical Field

The invention relates to the technical field of cables, and in particular to a high-conductivity flame-retardant cable and a production process thereof.

Background Art

Cables, also known as wires and cables, are the main carriers of power transmission and are widely used in electrical equipment, lighting lines, household appliances, etc. Their quality directly affects the quality of the project and the safety of life and property of consumers. With the continuous advancement of technology, some performance of cables no longer meets people's needs. For example, (1) The conductivity of cables with copper conductors as the conductive matrix will be oxidized due to long-term use, which will lead to a decrease in the conductivity of the cable; (2) Due to the frequent occurrence of fire incidents caused by cable aging, cables are required to have certain flame retardant properties. The flame retardant performance of traditional cables depends on the added content of flame retardants (magnesium hydroxide, calcium carbonate, etc.), but a large amount of flame retardants will affect the comprehensive performance of the cable.

In view of the defects of the above two properties, the surface of the copper conductor can be treated, such as spraying anti-oxidation coating or coating with anti-oxidation material, so as to reduce the decrease in conductivity caused by oxidation on the surface of the copper conductor, thereby improving the conductivity of the cable; design an organic-inorganic composite flame retardant that only adds a small amount and still has excellent flame retardant properties.

Summary of the invention

In order to solve the above technical problems, the present invention provides a high-conductivity flame-retardant cable and a production process thereof.

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

A high-conductivity flame-retardant cable comprises a conductor, an anti-oxidation layer, a shielding layer, an insulating layer and an outer sheath layer arranged in sequence from the inside to the outside;

The conductor is a copper conductor, the anti-oxidation layer is an anti-oxidation material, the insulating layer is polyvinyl chloride, and the outer sheath layer is a sheath material;

The sheath material comprises the following raw materials by weight: 100 parts of polyvinyl chloride resin, 5-7 parts of ACR resin, 8-15 parts of composite flame retardant, 1-3 parts of heat stabilizer, 3-5 parts of plasticizer, and 0.5-1 parts of antioxidant;

The composite flame retardant is prepared by the following method:

Step A1, add methyl phosphate, dichloromethane and triethylamine into a flask, stir in an ice-salt bath at -5°C for 30-50 minutes, then slowly drop acryloyl chloride dichloromethane solution into the flask, after the dropwise addition is completed, maintain the system temperature for 1 hour, raise the temperature to 30-40°C, continue the reaction for 8-12 hours, after the reaction is completed, filter, wash, and rotary evaporate, then add ethyl acetate and stir for 30 minutes, purify, and rotary evaporate to obtain intermediate 1;

Further, the dosage ratio of methyl phosphate, dichloromethane, triethylamine, acryloyl chloride dichloromethane solution and ethyl acetate is 1.4-4.2 g: 50 mL: 1.1-3.3 g: 10 mL: 30 mL, and the acryloyl chloride dichloromethane solution is prepared by mixing and stirring acryloyl chloride and dichloromethane in a dosage ratio of 0.9-2.7 g: 10 mL;

Step A2, add diethylamine and anhydrous methanol into a flask, stir for 20-30 min under nitrogen, then slowly dropwise add intermediate product 1 while stirring, after the dropwise addition is completed, raise the system temperature to 35°C, continue the reaction for 3-5 h, and then rotary evaporate to obtain intermediate product 2;

Further, the usage ratio of diethylamine, anhydrous methanol and intermediate product 1 is 0.02-0.04 mol:100 mL:0.01-0.02 mol;

Step A3, add the intermediate product 2 to a flask, stir at 45°C, then add 1-chlorododecane dropwise using a constant pressure separatory funnel, and continue the reaction for 8-12 hours. After the reaction is completed, let the mixture stand in the separatory funnel for 12 hours, separate the lower layer of liquid, rotate and freeze-dry for 8 hours to obtain a cationic intercalant;

Further, the molar ratio of the intermediate product 2 and 1-chlorododecane is 1:2;

Step A4, stirring and mixing the cationic intercalation agent in deionized water, recorded as solution 1; adding montmorillonite and deionized water into a flask, stirring and mixing, and then ultrasonically dispersing for 1 hour, raising the system temperature to 60-80°C, stirring for 5-8 hours, and then cooling to 5-20°C, slowly dropping solution 1, stirring and reacting for 3-7 hours, and after the reaction is completed, the intercalation modified montmorillonite is obtained;

Further, the dosage ratio of montmorillonite, deionized water and solution 1 is 1-2 g: 90 mL: 10 mL, and the dosage ratio of the cationic intercalation agent and deionized water in solution 1 is 0.05-0.3 g: 10 mL;

Step A5, 0.1-0.5g of copper nitrate is mixed evenly in 10mL of deionized water, recorded as solution 2; 0.1-0.5g of sodium molybdate is dispersed evenly in 10mL of deionized water, recorded as solution 3; the intercalated modified montmorillonite is dispersed in ethanol, solution 3 is added dropwise, the temperature is raised to 50-70°C, stirred for 5-7h, and then solution 2 is added dropwise, the temperature is maintained and stirred for 2-4h, after the reaction is completed, it is allowed to stand for 8-10h, centrifuged, filtered, washed, and dried to obtain a composite flame retardant;

Furthermore, the usage ratio of intercalated modified montmorillonite, ethanol, solution 2 and solution 3 is 1 g: 50 mL: 10 mL: 10 mL.

The antioxidant material comprises the following raw materials by weight: 30-40 parts of polyurethane rubber, 20-30 parts of nitrile rubber, 8-13 parts of silane coupling agent, 2-4 parts of zinc oxide, 3-5 parts of aluminum oxide, 5-8 parts of nano silicon dioxide, 1-2 parts of antioxidant 1010, 0.5-2 parts of sulfur, and 1-3 parts of accelerator.

A production process of a high-conductivity flame-retardant cable comprises the following steps:

Step S1, weighing raw materials by weight, mixing polyurethane rubber and nitrile rubber for 6-8 minutes, adding silane coupling agent, zinc oxide, aluminum oxide, nano-silicon dioxide, antioxidant and accelerator and mixing for 3-5 minutes, adding sulfur and mixing for 5 minutes to obtain a rubber mixture, adding the rubber mixture to a vulcanizer for vulcanization, and then extruding and coating the surface of the copper conductor to form an anti-oxidation layer;

Step S2, coating the surface of the anti-oxidation layer with an aluminum-plastic composite tape to form a shielding layer, and then coating the surface of the shielding layer with polyvinyl chloride to form an insulating layer;

Step S3, weighing the raw materials by weight, drying the polyvinyl chloride resin and the ACR resin at 80° C. for 1-3 hours, then uniformly mixing the dried polyvinyl chloride resin and the ACR resin with the composite flame retardant, the heat stabilizer, the plasticizer and the antioxidant in a high-speed mixer, and then melt-extruding and coating the insulating layer through a twin-screw extruder to form an outer sheath layer, thereby obtaining a high-conductivity flame-retardant cable;

Furthermore, in step S1, the temperature during vulcanization is 120-140° C., the pre-pressing pressure is 6-8 MPa, the vulcanization pressure is 10-12 MPa, and the vulcanization time is 8-10 min.

Beneficial effects of the present invention:

The cable produced in the present invention is provided with a conductor, an anti-oxidation layer, a shielding layer, an insulating layer and an outer sheath layer, wherein the addition of the anti-oxidation layer effectively reduces the decrease in conductivity caused by oxidation of the conductor and improves the conductivity of the cable; the composite flame retardant added to the sheath material used for the outer sheath layer improves the flame retardant performance of the cable.

The anti-oxidation layer set on the outer layer of the copper conductor is formed by extruding and coating the anti-oxidation material on the surface of the copper conductor. The anti-oxidation material is based on polyurethane rubber and nitrile rubber with good anti-oxidation properties as the main matrix, and zinc oxide, aluminum oxide and nano-silicon dioxide and other materials are added to further improve the anti-oxidation effect. The coating of the anti-oxidation layer can effectively reduce the surface oxidation of the copper conductor caused by long-term use. Surface oxidation will lead to a decrease in the conductivity of the conductor, thereby improving the conductivity of the cable.

In the composite flame retardant, the reaction between -OH in methyl phosphate and -COCl in acryloyl chloride is firstly used to generate an intermediate product 1 containing a double bond structure; the double bond in the intermediate product 1 is then used to react with the secondary amine in diethylamine to generate an intermediate product 2 containing a tertiary amine structure; the tertiary amine in the intermediate product 2 is then used to react with the chlorine atom in 1-chlorododecane to generate a cationic intercalation agent; the cationic intercalation agent is then used to exchange ions with cations between montmorillonite layers to obtain intercalation modified montmorillonite; finally, copper molybdate is loaded on the surface of montmorillonite by reaction of copper nitrate and sodium molybdate to obtain a composite flame retardant. The composite flame retardant uses the synergistic effect between organic flame retardants and inorganic flame retardants to improve the flame retardant properties of the matrix; the phosphate group contained in the cationic intercalant will undergo thermal decomposition during the combustion process, and the water and acidic substances produced by the decomposition can dilute the combustibles, and the released gas can isolate oxygen or dilute the combustible gas, and the phosphate can also promote the polymer to form a carbon layer. The N element introduced in the intercalant can also release flame-retardant gases (nitrogen, ammonia, etc.) during combustion, further improving the flame retardant properties of the matrix; due to its unique lamellar structure, montmorillonite can block the outward diffusion of combustible gases produced by the decomposition of the polymer during combustion, slow down the speed at which external oxygen enters the material, and at the same time promote the carbonization of the material and inhibit molten droplets; and the copper molybdate loaded on the surface of montmorillonite can decompose to produce _MoO3 and CuO during the combustion process, which can undergo cross-linking reactions with the polymer, promote carbonization reactions, and improve the density of the carbon layer. The formed carbon layer can play a role in heat insulation, oxygen isolation, and inhibition of the release of toxic smoke, further improving the flame retardant and smoke suppression effects of the matrix.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Example 1

The composite flame retardant is prepared by the following method:

Step A1, add 1.4g methyl phosphate, 50mL dichloromethane and 1.1g triethylamine into a flask, stir in an ice-salt bath at -5°C for 30min, then slowly drop 10mL acryloyl chloride dichloromethane solution into the flask, after the dropwise addition is completed, maintain the system temperature for reaction for 1h, raise the temperature to 30°C, and continue the reaction for 8h, after the reaction is completed, filter, wash, and rotary evaporate, then add 30mL ethyl acetate and stir for 30min, purify, and rotary evaporate to obtain intermediate 1, acryloyl chloride dichloromethane solution is prepared by mixing and stirring acryloyl chloride and dichloromethane in a dosage ratio of 0.9g:10mL;

Step A2, add 0.02 mol of diethylamine and 100 mL of anhydrous methanol into a flask, stir for 20 min under nitrogen, then slowly dropwise add 0.01 mol of intermediate 1 while stirring, after the dropwise addition is completed, raise the system temperature to 35°C, continue the reaction for 3 h, and then rotary evaporate to obtain intermediate 2;

Step A3, adding the intermediate product 2 into a flask, stirring at 45°C, then adding 1-chlorododecane dropwise using a constant pressure separatory funnel, and continuing the reaction for 8 hours. After the reaction is completed, the mixture is allowed to stand in the separatory funnel for 12 hours, the lower layer of liquid is separated, and the liquid is rotated and freeze-dried for 8 hours to obtain a cationic intercalant, and the molar ratio of the intermediate product 2 to 1-chlorododecane is 1:2;

Step A4, 0.05 g of cationic intercalation agent was stirred and mixed in 10 mL of deionized water, which was recorded as solution 1; 1 g of montmorillonite and 90 mL of deionized water were added to a flask and stirred evenly, and then ultrasonically dispersed for 1 hour, the system temperature was increased to 60° C., stirred for 5 hours, and then cooled to 5° C., 10 mL of solution 1 was slowly added dropwise, and the reaction was stirred for 3 hours. After the reaction was completed, the intercalated modified montmorillonite was obtained;

Step A5, 0.1g of copper nitrate was mixed evenly in 10mL of deionized water, recorded as solution 2; 0.1g of sodium molybdate was dispersed evenly in 10mL of deionized water, recorded as solution 3; 1g of intercalated modified montmorillonite was dispersed in 50mL of ethanol, 10mL of solution 3 was added dropwise, the temperature was raised to 50°C, stirred for 5h, and then 10mL of solution 2 was added dropwise, the temperature was maintained and stirred for 2h, after the reaction was completed, it was allowed to stand for 8h, centrifuged, filtered, washed and dried to obtain a composite flame retardant.

Example 2

The composite flame retardant is prepared by the following method:

Step A1, add 2.8g methyl phosphate, 50mL dichloromethane and 2.2g triethylamine into a flask, stir in an ice-salt bath at -5°C for 40min, then slowly drop 10mL acryloyl chloride dichloromethane solution into the flask, after the dropwise addition is completed, maintain the system temperature for reaction for 1h, raise the temperature to 35°C, continue the reaction for 10h, after the reaction is completed, filter, wash, and rotary evaporate, then add 30mL ethyl acetate and stir for 30min, purify, and rotary evaporate to obtain intermediate 1. The acryloyl chloride dichloromethane solution is prepared by mixing and stirring acryloyl chloride and dichloromethane in a dosage ratio of 1.8g:10mL;

Step A2, add 0.03 mol of diethylamine and 100 mL of anhydrous methanol into a flask, stir for 25 min under nitrogen, then slowly dropwise add 0.015 mol of intermediate 1 while stirring, after the dropwise addition is completed, raise the system temperature to 35°C, continue the reaction for 4 h, and then rotary evaporate to obtain intermediate 2;

Step A3, adding the intermediate product 2 into a flask, stirring at 45°C, then adding 1-chlorododecane dropwise using a constant pressure separatory funnel, and continuing the reaction for 10 hours. After the reaction is completed, the mixture is allowed to stand in the separatory funnel for 12 hours, the lower layer of liquid is separated, and the liquid is rotated and freeze-dried for 8 hours to obtain a cationic intercalant, and the molar ratio of the intermediate product 2 to 1-chlorododecane is 1:2;

Step A4, 0.1 g of cationic intercalation agent was stirred and mixed in 10 mL of deionized water, which was recorded as solution 1; 1.5 g of montmorillonite and 90 mL of deionized water were added to a flask and mixed and stirred evenly, and then ultrasonically dispersed for 1 hour, the system temperature was increased to 70° C., stirred for 6 hours, and then cooled to 10° C., 10 mL of solution 1 was slowly added dropwise, and the reaction was stirred for 5 hours. After the reaction was completed, the intercalated modified montmorillonite was obtained;

Step A5, 0.3g of copper nitrate was mixed evenly in 10mL of deionized water, recorded as solution 2; 0.3g of sodium molybdate was dispersed evenly in 10mL of deionized water, recorded as solution 3; 1g of intercalated modified montmorillonite was dispersed in 50mL of ethanol, 10mL of solution 3 was added dropwise, the temperature was raised to 60°C, stirred for 6h, and then 10mL of solution 2 was added dropwise, the temperature was maintained and stirred for 3h, after the reaction was completed, it was allowed to stand for 9h, centrifuged, filtered, washed and dried to obtain a composite flame retardant.

Example 3

The composite flame retardant is prepared by the following method:

Step A1, add 4.2g methyl phosphate, 50mL dichloromethane and 3.3g triethylamine into a flask, stir in an ice-salt bath at -5°C for 50min, then slowly drop 10mL acryloyl chloride dichloromethane solution into the flask, after the dropwise addition is completed, maintain the system temperature for reaction for 1h, raise the temperature to 40°C, and continue the reaction for 12h, after the reaction is completed, filter, wash, and rotary evaporate, then add 30mL ethyl acetate and stir for 30min, purify, and rotary evaporate to obtain intermediate 1. Acryloyl chloride dichloromethane solution is prepared by mixing and stirring acryloyl chloride and dichloromethane in a dosage ratio of 2.7g:10mL;

Step A2, add 0.04 mol of diethylamine and 100 mL of anhydrous methanol into a flask, stir for 30 min under nitrogen, then slowly dropwise add 0.02 mol of intermediate 1 while stirring, after the dropwise addition is completed, raise the system temperature to 35°C, continue the reaction for 5 h, and then rotary evaporate to obtain intermediate 2;

Step A3, adding the intermediate product 2 into a flask, stirring at 45°C, then adding 1-chlorododecane dropwise using a constant pressure separatory funnel, and continuing the reaction for 12 hours. After the reaction is completed, the mixture is allowed to stand in the separatory funnel for 12 hours, the lower layer of liquid is separated, and the liquid is rotated and freeze-dried for 8 hours to obtain a cationic intercalant, and the molar ratio of the intermediate product 2 to 1-chlorododecane is 1:2;

Step A4, 0.3 g of cationic intercalation agent was stirred and mixed in 10 mL of deionized water, which was recorded as solution 1; 2 g of montmorillonite and 90 mL of deionized water were added to a flask and stirred evenly, and then ultrasonically dispersed for 1 hour, the system temperature was increased to 80°C, stirred for 5-8 hours, and then cooled to 20°C, 10 mL of solution 1 was slowly added dropwise, and the reaction was stirred for 7 hours. After the reaction was completed, the intercalated modified montmorillonite was obtained;

Step A5, 0.5g of copper nitrate was mixed evenly in 10mL of deionized water, recorded as solution 2; 0.5g of sodium molybdate was dispersed evenly in 10mL of deionized water, recorded as solution 3; 1g of intercalated modified montmorillonite was dispersed in 50mL of ethanol, 10mL of solution 3 was added dropwise, the temperature was raised to 70°C, stirred for 7h, and then 10mL of solution 2 was added dropwise, the temperature was maintained and stirred for 4h. After the reaction was completed, it was allowed to stand for 10h, centrifuged, filtered, washed and dried to obtain a composite flame retardant.

Example 4

A high-conductivity flame-retardant cable, comprising a conductor, an anti-oxidation layer, a shielding layer, an insulating layer and an outer sheath layer arranged in sequence from the inside to the outside; the conductor is a copper conductor, the anti-oxidation layer is an anti-oxidation material, the insulating layer is polyvinyl chloride, and the outer sheath layer is a sheath material;

The sheath material comprises the following raw materials by weight: 100 parts of polyvinyl chloride resin, 5 parts of ACR resin, 8 parts of the composite flame retardant prepared in Example 1, 1 part of calcium stearate, 3 parts of diethyl phthalate, and 0.5 parts of antioxidant 1010;

The antioxidant material includes the following raw materials by weight: 30 parts of polyurethane rubber, 20 parts of nitrile rubber, 8 parts of KH-550, 2 parts of zinc oxide, 3 parts of aluminum oxide, 5 parts of nano silicon dioxide, 1 part of antioxidant 1010, 0.5 parts of sulfur, and 1 part of accelerator DPG;

The specific production process includes the following steps:

Step S1, weighing raw materials by weight, mixing polyurethane rubber and nitrile rubber for 6 minutes, then adding KH-550, zinc oxide, aluminum oxide, nano-silicon dioxide, antioxidant 1010 and accelerator DPG for 3 minutes, adding sulfur for 5 minutes to obtain a rubber mix, adding the rubber mix to a vulcanizer for vulcanization, and then extruding and coating the surface of the copper conductor to form an anti-oxidation layer, the temperature during vulcanization is 120° C., the pre-pressing pressure is 6 MPa, the vulcanization pressure is 10 MPa, and the vulcanization time is 8 minutes;

Step S2, coating the surface of the anti-oxidation layer with an aluminum-plastic composite tape to form a shielding layer, and then coating the surface of the shielding layer with polyvinyl chloride to form an insulating layer;

Step S3, weighing the raw materials by weight, drying the polyvinyl chloride resin and the ACR resin at 80°C for 1 hour, and then mixing the dried polyvinyl chloride resin and the ACR resin with the composite flame retardant, calcium stearate, diethyl phthalate and antioxidant 1010 prepared in Example 1 in a high-speed mixer, and then melt-extruding and coating them on the outside of the insulation layer through a twin-screw extruder to form an outer sheath layer, thereby obtaining a high-conductivity flame-retardant cable.

Example 5

A high-conductivity flame-retardant cable, comprising a conductor, an anti-oxidation layer, a shielding layer, an insulating layer and an outer sheath layer arranged in sequence from the inside to the outside; the conductor is a copper conductor, the anti-oxidation layer is an anti-oxidation material, the insulating layer is polyvinyl chloride, and the outer sheath layer is a sheath material;

The sheath material includes the following raw materials by weight: 100 parts of polyvinyl chloride resin, 6 parts of ACR resin, 12 parts of the composite flame retardant prepared in Example 2, 2 parts of calcium stearate, 4 parts of diethyl phthalate, and 0.8 parts of antioxidant 1010;

The antioxidant material includes the following raw materials by weight: 35 parts of polyurethane rubber, 25 parts of nitrile rubber, 10 parts of KH-550, 3 parts of zinc oxide, 4 parts of aluminum oxide, 6 parts of nano silicon dioxide, 1.5 parts of antioxidant 1010, 1 part of sulfur, and 2 parts of accelerator DPG;

The specific production process includes the following steps:

Step S1, weighing raw materials by weight, mixing polyurethane rubber and nitrile rubber for 7 minutes, then adding KH-550, zinc oxide, aluminum oxide, nano-silicon dioxide, antioxidant 1010 and accelerator DPG for 4 minutes, adding sulfur for 5 minutes to obtain a rubber mix, adding the rubber mix to a vulcanizer for vulcanization, and then extruding and coating the surface of the copper conductor to form an anti-oxidation layer, the temperature during vulcanization is 130° C., the pre-compression pressure is 7 MPa, the vulcanization pressure is 11 MPa, and the vulcanization time is 9 minutes;

Step S2, coating the surface of the anti-oxidation layer with an aluminum-plastic composite tape to form a shielding layer, and then coating the surface of the shielding layer with polyvinyl chloride to form an insulating layer;

Step S3, weighing the raw materials by weight, drying the polyvinyl chloride resin and the ACR resin at 80°C for 2h, and then mixing the dried polyvinyl chloride resin and the ACR resin with the composite flame retardant, calcium stearate, diethyl phthalate and antioxidant 1010 prepared in Example 2 in a high-speed mixer, and then melt-extruding and coating them on the outside of the insulation layer through a twin-screw extruder to form an outer sheath layer, thereby obtaining a high-conductivity flame-retardant cable.

Example 6

A high-conductivity flame-retardant cable, comprising a conductor, an anti-oxidation layer, a shielding layer, an insulating layer and an outer sheath layer arranged in sequence from the inside to the outside; the conductor is a copper conductor, the anti-oxidation layer is an anti-oxidation material, the insulating layer is polyvinyl chloride, and the outer sheath layer is a sheath material;

The sheath material comprises the following raw materials by weight: 100 parts of polyvinyl chloride resin, 7 parts of ACR resin, 15 parts of the composite flame retardant prepared in Example 3, 3 parts of calcium stearate, 5 parts of diethyl phthalate, and 1 part of antioxidant 1010;

The antioxidant material includes the following raw materials by weight: 40 parts of polyurethane rubber, 30 parts of nitrile rubber, 13 parts of KH-550, 4 parts of zinc oxide, 5 parts of aluminum oxide, 8 parts of nano silicon dioxide, 2 parts of antioxidant 1010, 2 parts of sulfur, and 3 parts of accelerator DPG;

The specific production process includes the following steps:

Step S1, weighing raw materials by weight, mixing polyurethane rubber and nitrile rubber for 8 minutes, then adding KH-550, zinc oxide, aluminum oxide, nano-silicon dioxide, antioxidant 1010 and accelerator DPG for 5 minutes, adding sulfur for 5 minutes to obtain a rubber mix, adding the rubber mix to a vulcanizer for vulcanization, and then extruding and coating the surface of a copper conductor to form an anti-oxidation layer, the temperature during vulcanization is 140° C., the pre-pressing pressure is 8 MPa, the vulcanization pressure is 12 MPa, and the vulcanization time is 10 minutes;

Step S2, coating the surface of the anti-oxidation layer with an aluminum-plastic composite tape to form a shielding layer, and then coating the surface of the shielding layer with polyvinyl chloride to form an insulating layer;

Step S3, weighing the raw materials by weight, drying the polyvinyl chloride resin and the ACR resin at 80°C for 3 hours, and then mixing the dried polyvinyl chloride resin and the ACR resin with the composite flame retardant, calcium stearate, diethyl phthalate and antioxidant 1010 prepared in Example 3 in a high-speed mixer, and then melt-extruding and coating them on the outside of the insulation layer through a twin-screw extruder to form an outer sheath layer, thereby obtaining a high-conductivity flame-retardant cable.

Comparative Example 1

This comparative example is a cable, which differs from Example 6 in that no anti-oxidation layer is provided, and the rest is the same.

Comparative Example 2

This comparative example is a cable, which is different from Example 6 in that an equal amount of magnesium hydroxide is used in the sheath material prepared in Example 3 to replace the composite flame retardant prepared in Example 3, and the rest are the same.

The cables prepared in Examples 4-6 and Comparative Examples 1-2 were subjected to performance tests:

Flame retardant performance test: oxygen index is measured according to GB/T 2406.2-2009 "Determination of combustion behavior of plastics by oxygen index method"; smoke density test: tested according to GB/T 8323.2-2008 standard; conductivity test: tested according to national standard GB3048.2-2007 standard; the test results are shown in the following table:

As can be seen from the above table, after the conductivity, limiting oxygen index and smoke density tests of the cable prepared by the present invention, the conductivity is in the range of 65.7-68.2, the limiting oxygen index is in the range of 35.4%-37.5%, and the smoke density is in the range of 226-245, indicating that the cable not only has high conductivity, but also has excellent flame retardant and smoke suppression properties.

The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they shall all fall within the protection scope of the present invention.

Claims (10)

1. The high-conductivity flame-retardant cable is characterized by comprising a conductor, an antioxidant layer, a shielding layer, an insulating layer and an outer sheath layer which are sequentially arranged from inside to outside;

The conductor is a copper conductor, the antioxidation layer is made of antioxidation materials, the insulating layer is polyvinyl chloride, and the outer sheath layer is sheath material;

The sheath material comprises the following raw materials in parts by weight: 100 parts of polyvinyl chloride resin, 5-7 parts of ACR resin, 8-15 parts of composite flame retardant, 1-3 parts of heat stabilizer, 3-5 parts of plasticizer and 0.5-1 part of antioxidant;

the composite flame retardant is prepared by the following method:

step A1, adding methyl phosphate, methylene dichloride and triethylamine into a flask, stirring for 30-50min in an ice salt bath at the temperature of minus 5 ℃, slowly dripping an acrylic chloride methylene dichloride solution into the flask, maintaining the system temperature for reaction for 1h after dripping is finished, heating to 30-40 ℃ for continuous reaction for 8-12h, filtering, washing, steaming in a rotary mode after the reaction is finished, adding ethyl acetate, stirring for 30min, purifying, steaming in a rotary mode, and obtaining an intermediate product 1;

Step A2, adding diethylamine and absolute methanol into a flask, stirring for 20-30min under the condition of nitrogen, slowly dropwise adding the intermediate product 1 while stirring, raising the temperature of the system to 35 ℃ after the dropwise adding is finished, and performing continuous reaction for 3-5h, and performing rotary evaporation to obtain an intermediate product 2;

Step A3, adding the intermediate product 2 into a flask, stirring at 45 ℃, then dropwise adding 1-chlorododecane by using a constant pressure separating funnel, continuously reacting for 8-12h, standing the mixture in the separating funnel for 12h after the reaction is finished, separating out lower-layer liquid, rotating, and freeze-drying for 8h to obtain the cation intercalation agent;

Step A4, uniformly stirring and mixing the cationic intercalating agent in deionized water, and marking as a solution 1; adding montmorillonite and deionized water into a flask, mixing and stirring uniformly, performing ultrasonic dispersion for 1h, increasing the temperature of the system to 60-80 ℃, stirring for 5-8h, cooling to 5-20 ℃, slowly dripping solution 1, stirring and reacting for 3-7h, and obtaining intercalation modified montmorillonite after the reaction is finished;

Step A5, uniformly mixing 0.1-0.5g of copper nitrate in 10mL of deionized water, and marking as a solution 2;0.1-0.5g sodium molybdate is uniformly dispersed in 10mL deionized water and is marked as solution 3; dispersing intercalation modified montmorillonite in ethanol, dropwise adding solution 3, heating to 50-70 ℃, stirring for 5-7h, dropwise adding solution 2, maintaining the temperature, stirring for 2-4h, standing for 8-10h after the reaction is finished, centrifuging, filtering, washing and drying to obtain the composite flame retardant.

2. The highly conductive flame retardant cable of claim 1, wherein the ratio of methyl phosphate, methylene chloride, triethylamine, acrylic chloride methylene chloride solution and ethyl acetate used in step A1 is 1.4-4.2g:50mL:1.1-3.3g:10mL:30mL.

3. The highly conductive flame retardant cable of claim 2, wherein the acrylic chloride methylene chloride solution of step A1 is prepared from acrylic chloride and methylene chloride at a ratio of 0.9-2.7g: the dosage ratio of 10mL is mixed and stirred.

4. The highly conductive flame retardant cable of claim 1, wherein the amount ratio of diethylamine, anhydrous methanol and intermediate 1 in step A2 is 0.02 to 0.04mol:100mL:0.01-0.02mol.

5. A highly conductive flame retardant cable according to claim 1, wherein the mass ratio of intermediate 2 to 1-chlorododecane in step A3 is 1:2.

6. The highly conductive flame retardant cable of claim 1, wherein the ratio of montmorillonite, deionized water and solution 1 in step A4 is 1-2g:90mL:10mL, the dosage ratio of the cationic intercalating agent to deionized water in the solution 1 is 0.05-0.3g:10mL.

7. The highly conductive flame retardant cable of claim 1, wherein the intercalation modified montmorillonite, ethanol, solution 2 and solution 3 in step A5 are used in an amount ratio of 1g:50mL:10mL:10mL.

8. The high-conductivity flame-retardant cable according to claim 1, wherein the antioxidant material comprises the following raw materials in parts by weight: 30-40 parts of polyurethane rubber, 20-30 parts of nitrile rubber, 8-13 parts of silane coupling agent, 2-4 parts of zinc oxide, 3-5 parts of aluminum oxide, 5-8 parts of nano silicon dioxide, 1-2 parts of antioxidant 1010, 0.5-2 parts of sulfur and 1-3 parts of accelerator.

9. The process for producing a highly conductive flame retardant cable according to claim 1, comprising the steps of:

s1, weighing raw materials according to parts by weight, mixing polyurethane rubber and nitrile rubber for 6-8min, adding a silane coupling agent, zinc oxide, aluminum oxide, nano silicon dioxide, an antioxidant and an accelerator, mixing for 3-5min, adding sulfur, mixing for 5min to obtain a mixed rubber, adding the mixed rubber into a vulcanizing machine, vulcanizing, and extruding and coating on the surface of a copper conductor to form an antioxidant layer;

S2, coating an aluminum-plastic composite belt on the surface of the antioxidant layer to form a shielding layer, and coating polyvinyl chloride on the surface of the shielding layer to form an insulating layer;

And S3, weighing raw materials according to parts by weight, drying polyvinyl chloride resin and ACR resin at 80 ℃ for 1-3 hours, uniformly mixing the dried polyvinyl chloride resin and ACR resin with a composite flame retardant, a heat stabilizer, a plasticizer and an antioxidant in a high-speed mixer, and carrying out melt extrusion coating on the insulating layer by a double-screw extruder to form an outer sheath layer, thus obtaining the high-conductivity flame-retardant cable.

10. The process for producing a highly conductive flame retardant cable according to claim 9, wherein the temperature at the time of vulcanization in step S1 is 120-140 ℃, the pre-compression pressure is 6-8MPa, the vulcanization pressure is 10-12MPa, and the vulcanization time is 8-10min.