High-cold-resistant flame-retardant cable and preparation method thereof

Abstract

The invention discloses a high-cold-resistant flame-retardant cable and a preparation method thereof, and relates to the technical field of cables. According to the invention, 3-(3-tert-butyl-4-hydroxy) methyl phenylpropionate and N-butyl-2, 2, 6, 6-tetramethyl-4-piperidylamine are used as raw materials to form a main anti-aging agent integrating light stability and oxidation resistance, and modified porous carbon is used as a carrier to promote the slow release property of the anti-aging agent, that is, the anti-aging agent is slowly released from gaps under the action of heat, oxygen, light and a solvent, so that the anti-aging effect of the anti-aging agent is improved. Groups on the surface of the porous carbon material can improve the bonding force between polypropylene and the interface of the polypropylene, so that the two-phase interface bonding is tighter, oxygen is prevented from freely diffusing from the surface to the inside, and the anti-aging performance of the cable sheath layer is further improved; and the cold-resistant, flame-retardant and anti-aging performances of the cable sheath layer are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of cables, and in particular to a cold-resistant flame-retardant cable and a preparation method thereof. Background Art

[0002] Polypropylene has the advantages of abundant sources and low prices. Compared with other general-purpose plastics, it has good mechanical properties, low density, good rigidity, high strength and good electrical insulation properties. It is currently widely used in the cable field. However, since polypropylene contains unstable tertiary carbon groups, it is easily attacked by heat, oxygen and ultraviolet rays, resulting in performance deterioration. The existing improvement method is generally to improve the heat and oxygen aging resistance of polypropylene by adding high-efficiency antioxidants, but they are limited to the selection and addition amount of antioxidants. Not only is the addition amount large and the added variety is single, but the heat and oxygen aging resistance is not good. Summary of the invention

[0003] The object of the present invention is to provide a high-cold resistant flame-retardant cable and a preparation method thereof, so as to solve the problems existing in the prior art.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a high-cold resistant flame-retardant cable, comprising a core, an insulating layer, a shielding layer, and a sheath layer, wherein the main raw materials of the sheath layer include polypropylene, composite filler, EPDM rubber, and diethyl phosphite.

[0005] Furthermore, the preparation method of the sheath layer is as follows:

[0006] (1) 15-30 g of methyl 3-(3-tert-butyl-4-hydroxy)benzenepropanoate and 55-70 g of water were mixed and heated to 70° C., then 0.1-0.4 g of sodium dodecylbenzene sulfonate was added, and the mixture was stirred at 40-60 rpm for 15 min. Then 7-11 g of 36 wt% formaldehyde aqueous solution was added, and the stirring was continued for 15 min. Then 1.0-1.50 g of industrial phosphoric acid was added, and the mixture was heated to 80° C. and kept warm for 4-7 h. After the reaction was completed, the mixture was filtered while hot, and the filter cake was washed four times with 110 g of 90° C. hot water by beating, and then filtered. The filter cake was dried at 70° C. to constant weight to obtain intermediate A;

[0007] (2) 10-16 g of intermediate A and 5-8 g of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine were dissolved in 45 g of toluene, and the temperature was raised to 60° C. under N2 protection. After adding 0.4 g of KOH, the temperature was raised to 80° C. After the reaction was completed, the temperature was cooled to 60° C., 88 g of toluene was added, and the pH of the reaction solution was adjusted to 5-6 with glacial acetic acid. Then 30 g of distilled water was added, and the mixture was stirred at 40-60 rpm for 30 min. The mixture was allowed to stand for separation of water. After dehydration, 1 g of activated carbon was added, and the mixture was stirred at 80 rpm for 30 min. The mixture was filtered while hot. The filtrate was cooled to room temperature and filtered. The filter cake was washed three times with 40 g of toluene by pulping, and the filter cake was filtered by suction. The filter cake was dried at 50° C. to constant weight to obtain the main antioxidant;

[0008] (3) preparing a modified solution with a mass ratio of 1:5-10 for hydroxyl-terminated methyl vinyl silicone oil and anhydrous ethanol, adding porous carbon, mixing the porous carbon and the hydroxyl-terminated methyl vinyl silicone oil with a mass ratio of 1:0.1-0.5, stirring at 300-900 rpm for 30 min, evaporating the organic solvent, and drying at 80-120° C. for 4-8 h to obtain the modified porous carbon;

[0009] (4) dissolving 1-3 g of the main antioxidant in 10-15 g of acetone, adding 20-30 g of modified porous carbon after sufficient dissolution, drying at room temperature after sufficient absorption, and placing the modified porous carbon in a vacuum oven after the surface is dry, and drying at 40° C. for 2 h to obtain a composite filler;

[0010] (5) Extruding and granulating 100 parts of polypropylene and 10 to 15 parts of composite filler at 200 to 230° C. to obtain a polypropylene composite;

[0011] (6) In parts by weight, 50-60 parts of EPDM rubber, 0.2-0.6 parts of polyethylene wax, and 4-8 parts of diethyl phosphite are mixed at 100-150° C. for 8-10 minutes, and then extruded through a twin-screw extruder to form a rubber masterbatch; 100 parts of the rubber masterbatch and 100-150 parts of the polypropylene compound are mixed in proportion in a twin-screw extruder for rubber and plastic blending and extrusion granulation, the twin-screw temperature is 190° C., the speed is 200 rpm, to obtain a rubber masterbatch, and then 100 parts of the rubber masterbatch and 4-8 parts of the vulcanizing agent NFCP-P are vulcanized and extruded in a twin-screw extruder, the screw extruder ￠=35mmL / D=56, the temperature is 200° C., and the speed is 300 rpm, to obtain a sheath layer

[0012] Furthermore, the hydroxyl content of the hydroxyl-terminated methyl vinyl silicone oil in step (3) is 9 to 12 wt %, and the vinyl content is 2.5 to 6 wt %.

[0013] Furthermore, the porous carbon in step (3) is coal-based porous carbon with a porosity of 50-60% and a particle size of 15-35 μm.

[0014] Furthermore, the melt mass flow rate of the polypropylene in step (5) measured at 230°C / 2.16kg is 10 to 30 g / 10min.

[0015] Furthermore, the performance parameters of the EPDM rubber in step (6) are: Mooney viscosity of 45, ethylene content of 44.5%, and ENB content of 7.6% tested at 100°C.

[0016] Furthermore, the wire core is a copper wire.

[0017] Furthermore, the insulating layer is a polyethylene insulating layer.

[0018] Furthermore, the shielding layer is made of a mesh woven from copper wires.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0020] The invention uses 3-(3-tert-butyl-4-hydroxy)phenylpropionic acid methyl ester as a raw material, connects its benzene rings under acid catalysis to form a special hindered phenol compound with a bisphenol structure, and uses the compound as a main antioxidant of a cable sheath material. The compound can capture free radicals, prevent the development of an oxidation chain reaction of a polypropylene base material, and preliminarily realize the anti-aging performance of a cable sheath layer. On this basis, an ester group reacts with an amino group in an N-butyl group of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine to form a main antioxidant with light stability and anti-oxidation. The invention uses vinyl hydroxy silicone oil to modify porous carbon, so that the surface of the porous carbon carries vinyl groups and hydroxyl groups at the same time, and there is a strong intermolecular force between the main antioxidant and the main antioxidant, which greatly improves the stabilizing effect of the main antioxidant. Therefore, the compound is used as a carrier to promote the sustained release of the antioxidant, that is, under the action of heat, oxygen, light and solvent, the antioxidant is slowly released from the gap to extend its service life.

[0021] The present invention preferentially extrude and granulate polypropylene and a porous carbon material loaded with an antioxidant, so that the antioxidant is embedded in a polypropylene matrix to avoid direct contact between the antioxidant and EPDM rubber, thereby affecting the later vulcanization speed. The vinyl on the surface of the porous carbon material can improve the interfacial adhesion between the polypropylene and the EPDM rubber, make the two-phase interface more tightly bonded, and prevent oxygen from freely diffusing from the surface to the inside, thereby further improving the anti-aging performance of the cable sheath layer. In addition, EPDM rubber and diethyl phosphite are compounded to greatly improve the cold resistance, flame retardancy and anti-aging performance of the cable sheath layer. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] A flame-retardant cable resistant to high cold weather comprises a copper wire core, a polyethylene insulation layer, a copper wire braided shielding layer, and a sheath layer; the preparation method of the sheath layer is as follows:

[0025] (1) 15 g of methyl 3-(3-tert-butyl-4-hydroxy)benzenepropanoate and 60 g of water were mixed and heated to 70° C., then 0.25 g of sodium dodecylbenzene sulfonate was added, and the mixture was stirred at 50 rpm for 15 min. Then 7 g of 36 wt% formaldehyde aqueous solution was added, and the stirring was continued for 15 min. Then 1.50 g of industrial phosphoric acid was added, and the mixture was heated to 80° C. and kept for reaction for 4 h. After the reaction was completed, the mixture was filtered while hot, and the filter cake was washed four times with 110 g of 90° C. hot water by beating and suction filtering, and the filter cake was dried at 70° C. to constant weight to obtain intermediate A;

[0026] (2) 10 g of intermediate A and 5 g of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine were dissolved in 45 g of toluene. The temperature was raised to 60° C. under N2 protection. 0.4 g of KOH was added and the temperature was raised to 80° C. After the reaction, the temperature was cooled to 60° C., 88 g of toluene was added, and the pH of the reaction solution was adjusted to 5 with glacial acetic acid. 30 g of distilled water was added, and the mixture was stirred at 50 rpm for 30 min. The mixture was allowed to stand for separation of water. After dehydration, 1 g of activated carbon was added, and the mixture was stirred at 80 rpm for 30 min. The mixture was filtered while hot. The filtrate was cooled to room temperature and filtered. The filter cake was washed three times with 40 g of toluene by pulping, and the filter cake was filtered by suction. The filter cake was dried at 50° C. to constant weight to obtain the main antioxidant.

[0027] (3) preparing a modified solution with hydroxyl-terminated methyl vinyl silicone oil and anhydrous ethanol in a mass ratio of 1:5, adding porous carbon, mixing the porous carbon and hydroxyl-terminated methyl vinyl silicone oil in a mass ratio of 1:0.1, stirring at 800 rpm for 30 minutes, evaporating the organic solvent, and drying at 100° C. for 4 hours to obtain modified porous carbon;

[0028] (4) Dissolve 1 g of the main antioxidant in 15 g of acetone. After fully dissolved, add 20 g of modified porous carbon. After fully absorbed, dry at room temperature. After the surface of the modified porous carbon is dry, put it into a vacuum oven and dry it at 40° C. for 2 h to obtain a composite filler.

[0029] (5) 100 parts of polypropylene and 10 parts of composite filler are extruded and granulated at 220° C. to obtain a polypropylene composite;

[0030] (6) In parts by weight, 50 parts of ethylene propylene diene monomer rubber, 0.2 parts of polyethylene wax, and 4 parts of diethyl phosphite were mixed at 150° C. for 8 minutes, and then extruded through a twin-screw extruder to prepare a rubber masterbatch; 100 parts of the rubber masterbatch and 100 parts of the polypropylene compound were mixed in proportion in a twin-screw extruder for rubber and plastic blending and extrusion granulation, the twin-screw temperature was 190° C., and the speed was 200 rpm, to prepare the rubber masterbatch; then 100 parts of the rubber masterbatch and 4 parts of the vulcanizing agent NFCP-P were vulcanized and extruded in a twin-screw extruder, the screw extruder ￠=35mmL / D=56, the temperature was 200° C., and the speed was 300 rpm, to obtain the sheath layer.

[0031] Example 2

[0032] A flame-retardant cable resistant to high cold weather comprises a copper wire core, a polyethylene insulation layer, a copper wire braided shielding layer, and a sheath layer; the preparation method of the sheath layer is as follows:

[0033] (1) 22 g of methyl 3-(3-tert-butyl-4-hydroxy)benzenepropanoate and 60 g of water were mixed and heated to 70° C., then 0.25 g of sodium dodecylbenzene sulfonate was added, and the mixture was stirred at 50 rpm for 15 min. Then 10 g of 36 wt% formaldehyde aqueous solution was added, and the stirring was continued for 15 min. Then 1.50 g of industrial phosphoric acid was added, and the mixture was heated to 80° C. and kept for reaction for 5 h. After the reaction was completed, the mixture was filtered while hot, and the filter cake was washed four times with 110 g of 90° C. hot water by beating and suction filtering, and the filter cake was dried at 70° C. to constant weight to obtain intermediate A;

[0034] (2) 13 g of intermediate A and 6 g of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine were dissolved in 45 g of toluene. The temperature was raised to 60° C. under N2 protection. 0.4 g of KOH was added and the temperature was raised to 80° C. After the reaction, the temperature was cooled to 60° C., 88 g of toluene was added, and the pH of the reaction solution was adjusted to 5.5 with glacial acetic acid. 30 g of distilled water was added, and the mixture was stirred at 50 rpm for 30 min. The mixture was allowed to stand for separation of water. After dehydration, 1 g of activated carbon was added, and the mixture was stirred at 80 rpm for 30 min. The mixture was filtered while hot. The filtrate was cooled to room temperature and filtered. The filter cake was washed three times with 40 g of toluene by pulping, and the filter cake was filtered by suction. The filter cake was dried at 50° C. to constant weight to obtain the main antioxidant.

[0035] (3) preparing a modified solution with hydroxyl-terminated methyl vinyl silicone oil and anhydrous ethanol in a mass ratio of 1:8, adding porous carbon, mixing the porous carbon and hydroxyl-terminated methyl vinyl silicone oil in a mass ratio of 1:0.3, stirring at 800 rpm for 30 min, evaporating the organic solvent, and drying at 100° C. for 6 h to obtain modified porous carbon;

[0036] (4) Dissolve 2 g of the main antioxidant in 15 g of acetone. After fully dissolved, add 25 g of modified porous carbon. After fully absorbed, dry at room temperature. After the surface of the modified porous carbon is dry, put it into a vacuum oven and dry it at 40° C. for 2 h to obtain a composite filler.

[0037] (5) 100 parts of polypropylene and 12 parts of composite filler are extruded and granulated at 220° C. to obtain a polypropylene composite;

[0038] (6) In parts by weight, 55 parts of ethylene propylene diene monomer rubber, 0.4 parts of polyethylene wax, and 6 parts of diethyl phosphite were mixed at 150° C. for 8 minutes, and then extruded through a twin-screw extruder to prepare a rubber masterbatch; 100 parts of the rubber masterbatch and 120 parts of the polypropylene compound were mixed in proportion in a twin-screw extruder for rubber and plastic blending and extrusion granulation, the twin-screw temperature was 190° C., and the speed was 200 rpm to prepare the rubber masterbatch; then 100 parts of the rubber masterbatch and 6 parts of the vulcanizing agent NFCP-P were vulcanized and extruded in a twin-screw extruder, the screw extruder ￠=35mmL / D=56, the temperature was 200° C., and the speed was 300 rpm to obtain the sheath layer.

[0039] Example 3

[0040] A flame-retardant cable resistant to high cold weather comprises a copper wire core, a polyethylene insulation layer, a copper wire braided shielding layer, and a sheath layer; the preparation method of the sheath layer is as follows:

[0041] (1) 30 g of methyl 3-(3-tert-butyl-4-hydroxy)benzenepropanoate and 60 g of water were mixed and heated to 70° C., then 0.25 g of sodium dodecylbenzene sulfonate was added, and the mixture was stirred at 50 rpm for 15 min. Then 11 g of 36 wt% formaldehyde aqueous solution was added, and the stirring was continued for 15 min. Then 1.50 g of industrial phosphoric acid was added, and the mixture was heated to 80° C. and kept for reaction for 7 h. After the reaction was completed, the mixture was filtered while hot, and the filter cake was washed four times with 110 g of 90° C. hot water by beating and suction filtering, and the filter cake was dried at 70° C. to constant weight to obtain intermediate A;

[0042] (2) 16 g of intermediate A and 8 g of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine were dissolved in 45 g of toluene. The temperature was raised to 60° C. under N2 protection. 0.4 g of KOH was added and the temperature was raised to 80° C. After the reaction was completed, the temperature was cooled to 60° C. 88 g of toluene was added. The pH of the reaction solution was adjusted to 6 with glacial acetic acid. 30 g of distilled water was added and the mixture was stirred at 50 rpm for 30 min. The mixture was allowed to stand for separation of water. After dehydration, 1 g of activated carbon was added and the mixture was stirred at 80 rpm for 30 min. The mixture was filtered while hot. The filtrate was cooled to room temperature and filtered. The filter cake was washed three times with 40 g of toluene by pulping. The filter cake was filtered by suction and dried at 50° C. to constant weight to obtain the main antioxidant.

[0043] (3) preparing a modified solution with hydroxyl-terminated methyl vinyl silicone oil and anhydrous ethanol in a mass ratio of 1:10, adding porous carbon, mixing the porous carbon and hydroxyl-terminated methyl vinyl silicone oil in a mass ratio of 1:0.5, stirring at 800 rpm for 30 minutes, evaporating the organic solvent, and drying at 100° C. for 8 hours to obtain modified porous carbon;

[0044] (4) Dissolve 3 g of the main antioxidant in 15 g of acetone. After fully dissolved, add 30 g of modified porous carbon. After fully absorbed, dry at room temperature. After the surface of the modified porous carbon is dry, put it into a vacuum oven and dry it at 40° C. for 2 h to obtain a composite filler.

[0045] (5) 100 parts of polypropylene and 15 parts of composite filler are extruded and granulated at 220° C. to obtain a polypropylene composite;

[0046] (6) In parts by weight, 60 parts of ethylene propylene diene monomer rubber, 0.6 parts of polyethylene wax, and 8 parts of diethyl phosphite were mixed at 150° C. for 10 minutes and then extruded through a twin-screw extruder to prepare a rubber masterbatch; 100 parts of the rubber masterbatch and 150 parts of the polypropylene compound were mixed and extruded into granules in a twin-screw extruder according to a proportion, the twin-screw temperature was 190° C., and the speed was 200 rpm to prepare the rubber masterbatch; then 100 parts of the rubber masterbatch and 8 parts of the vulcanizing agent NFCP-P were vulcanized and extruded in a twin-screw extruder, the screw extruder ￠=35 mmL / D=56, the temperature was 200° C., and the speed was 300 rpm to obtain the sheath layer.

[0047] Comparative Example 1

[0048] The difference between Comparative Example 1 and Example 1 is that 3-(3-tert-butyl-4-hydroxy)phenylpropionic acid methyl ester is not added, the main antioxidant component is N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, and the remaining steps are the same as Example 1.

[0049] Comparative Example 2

[0050] The difference between Comparative Example 2 and Example 1 is that N-butyl-2,2,6,6-tetramethyl-4-piperidinamine is not added, the main antioxidant component is 3-(3-tert-butyl-4-hydroxy)phenylpropionic acid methyl ester, and the remaining steps are the same as Example 1.

[0051] Comparative Example 3

[0052] The difference between Comparative Example 3 and Example 1 is that the porous carbon is not modified, and the remaining steps are the same as Example 1.

[0053] Effect example

[0054] The following table shows the results of the ultraviolet aging of the cables of Examples 1 to 3 of the present invention and Comparative Examples 1 to 3 under the condition of 0.89 W / m2 , temperature is 100℃, aging time is 240h, the test results are shown in the following table:

[0055]

[0056]

[0057] The invention uses 3-(3-tert-butyl-4-hydroxy)phenylpropionic acid methyl ester and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine as raw materials to form a main antioxidant with light stability and anti-oxidation, and uses modified porous carbon as a carrier to promote the slow release of the antioxidant, that is, under the action of heat, oxygen, light and solvent, the antioxidant is slowly released from the gap to extend the service life of the antioxidant, and the groups on the surface of the porous carbon material can improve the interface adhesion between polypropylene and the polypropylene, so that the interface of the two phases is more tightly combined, and oxygen is prevented from freely diffusing from the surface to the inside, thereby further improving the anti-aging performance of the cable sheath layer, and compounding ethylene propylene rubber and diethyl phosphite greatly improves the cold resistance, flame retardancy and anti-aging performance of the cable sheath layer.

[0058] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A flame-retardant cable resistant to high cold weather, comprising a core, an insulating layer, a shielding layer, and a sheath layer, characterized in that: The main raw materials of the sheath layer include polypropylene, composite filler, EPDM rubber and diethyl phosphite.

2. The flame-retardant cable resistant to high cold weather according to claim 1, characterized in that: The preparation method of the sheath layer is as follows: (1) 15-30 g of methyl 3-(3-tert-butyl-4-hydroxy)benzenepropanoate and 55-70 g of water were mixed and heated to 70° C., then 0.1-0.4 g of sodium dodecylbenzene sulfonate was added, and the mixture was stirred at 40-60 rpm for 15 min. Then 7-11 g of 36 wt% formaldehyde aqueous solution was added, and the stirring was continued for 15 min. Then 1.0-1.50 g of industrial phosphoric acid was added, and the mixture was heated to 80° C. and kept warm for 4-7 h. After the reaction was completed, the mixture was filtered while hot, and the filter cake was washed four times with 110 g of 90° C. hot water by beating, and then filtered. The filter cake was dried at 70° C. to constant weight to obtain intermediate A; (2) 10-16 g of intermediate A and 5-8 g of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine were dissolved in 45 g of toluene, and the temperature was raised to 60° C. under N2 protection. After adding 0.4 g of KOH, the temperature was raised to 80° C. After the reaction was completed, the temperature was cooled to 60° C., 88 g of toluene was added, and the pH of the reaction solution was adjusted to 5-6 with glacial acetic acid. Then 30 g of distilled water was added, and the mixture was stirred at 40-60 rpm for 30 min. The mixture was allowed to stand for separation of water. After dehydration, 1 g of activated carbon was added, and the mixture was stirred at 80 rpm for 30 min. The mixture was filtered while hot. The filtrate was cooled to room temperature and filtered. The filter cake was washed three times with 40 g of toluene by pulping, and the filter cake was filtered by suction. The filter cake was dried at 50° C. to constant weight to obtain the main antioxidant; (3) preparing a modified solution with a mass ratio of 1:5-10 for hydroxyl-terminated methyl vinyl silicone oil and anhydrous ethanol, adding porous carbon, mixing the porous carbon and the hydroxyl-terminated methyl vinyl silicone oil with a mass ratio of 1:0.1-0.5, stirring at 300-900 rpm for 30 min, evaporating the organic solvent, and drying at 80-120° C. for 4-8 h to obtain the modified porous carbon; (4) dissolving 1-3 g of the main antioxidant in 10-15 g of acetone, adding 20-30 g of modified porous carbon after sufficient dissolution, drying at room temperature after sufficient absorption, and placing the modified porous carbon in a vacuum oven after the surface is dry, and drying at 40° C. for 2 h to obtain a composite filler; (5) Extruding and granulating 100 parts of polypropylene and 10 to 15 parts of composite filler at 200 to 230° C. to obtain a polypropylene composite; (6) In parts by weight, 50-60 parts of EPDM rubber, 0.2-0.6 parts of polyethylene wax, and 4-8 parts of diethyl phosphite are mixed at 100-150° C. for 8-10 minutes, and then extruded through a twin-screw extruder to prepare a rubber masterbatch; 100 parts of the rubber masterbatch and 100-150 parts of the polypropylene compound are mixed in proportion in a twin-screw extruder for rubber and plastic blending and extrusion granulation, the twin-screw temperature is 190° C., the speed is 200 rpm, to prepare a rubber masterbatch, and then 100 parts of the rubber masterbatch and 4-8 parts of the vulcanizing agent NFCP-P are vulcanized and extruded in a twin-screw extruder, and the screw extruder is used for the extrusion molding. The temperature is 200°C and the rotation speed is 300rpm to obtain the sheath layer.

3. The flame-retardant cable resistant to high cold weather according to claim 2, characterized in that: The hydroxyl content of the hydroxy-terminated methyl vinyl silicone oil in step (3) is 9-12wt%, and the vinyl content is 2.5-6wt%.

4. The flame-retardant cable resistant to high cold weather according to claim 2, characterized in that: The porous carbon in step (3) is coal-based porous carbon with a porosity of 50-60% and a particle size of 15-35 μm.

5. The high cold resistant flame retardant cable according to claim 2, characterized in that: The melt mass flow rate of the polypropylene in step (5) measured at 230°C / 2.16kg is 10 to 30 g / 10min.

6. The high cold resistant flame retardant cable according to claim 2, characterized in that: The performance parameters of the EPDM rubber in step (6) are: Mooney viscosity of 45, ethylene content of 44.5%, and ENB content of 7.6% tested at 100°C.

7. The high cold resistant flame retardant cable according to claim 1, characterized in that: The wire core is a copper wire.

8. The high cold resistant flame retardant cable according to claim 1, characterized in that: The insulating layer is a polyethylene insulating layer.

9. The high cold resistant flame retardant cable according to claim 1, characterized in that: The shielding layer is made of a mesh woven from copper wires.

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