Highly flame-retardant insulated power cable

Abstract

The application discloses a high-flame-retardant insulating power cable, which comprises a plurality of conductors arranged in sequence from inside to outside, the surface of the conductors is coated with an insulating layer, the outside of the insulating layer is provided with a wrapping inner liner layer, the wrapping inner liner layer and the insulating layer are filled with a filler, the outside of the wrapping inner liner layer is coated with a protective layer, the outside of the protective layer is coated with a sheath, and the sheath is prepared from modified resin. When the cable is burned, a dense fluoride protective film is formed on the surface of the cable, thereby isolating oxygen and flame. Organic phosphorus on the surface will decompose to generate phosphoric acid, metaphosphoric acid and poly-metaphosphoric acid and other substances when heated, can make the polymer surface dehydrate and carbonize, and can form a dense silicon-nitrogen layer by compounding with the organic silicon structure, and the doping of boron and nitrogen elements further improves the density of the silicon-carbon layer, a multilayer protective layer is formed on the surface of the cable, the generation of dripping objects is effectively avoided, and carbon nanotubes can form a network structure, the structure can play a role in blocking oxygen and heat transfer, and the flame-retardant effect is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flame-retardant cable material preparation, and particularly relates to a high-flame-retardant insulated power cable. BACKGROUND

[0002] The power cable is a cable for transmitting and distributing electric energy, and is often used in urban underground power grids, power station outgoing lines, internal power supply of industrial and mining enterprises and underwater power transmission lines across rivers and seas. In power lines, the proportion of cables is gradually increasing. The power cable is a cable product used for transmitting and distributing high-power electric energy in the main line of the power system, including 1-500KV and above various voltage levels and various insulation power cables. The traditional flame-retardant power cable adds halogen-containing or non-halogen-containing flame retardants to improve the flame retardance of the cable. Although the performance of the cable under the condition of fire can be significantly improved, there are problems such as large amount of smoke generation, serious emission of harmful gases and fast aging and deterioration. In addition, halogen-containing materials may generate extremely toxic acid gases when dissolved in water, which has a great impact on the environment and human health. Therefore, developing a new type of environmentally friendly and efficient flame-retardant power cable has become a technical problem to be solved. SUMMARY

[0003] The present application aims to provide a high-flame-retardant insulated power cable, which solves the problem of poor flame-retardant effect of the power cable at the present stage and the problem of fire spreading caused by dripping during combustion.

[0004] The purpose of the present application can be achieved by the following technical solutions.

[0005] A high-flame-retardant insulated power cable comprises a plurality of conductors arranged in sequence from inside to outside, the surface of the conductor is coated with an insulation layer, the outside of the insulation layer is provided with a wrapping inner liner layer, the wrapping inner liner layer and the insulation layer are filled with a filler, the outside of the wrapping inner liner layer is coated with a protective layer, and the outside of the protective layer is coated with a sheath.

[0006] The conductor is a tinned copper wire, the wrapping inner liner layer is a mica tape, the filler is a glass fiber, the insulation layer and the protective layer are polyvinyl chloride, and the sheath is prepared from a modified resin.

[0007] Further, the modified resin is prepared by the following steps:

[0008] Step A1: uniformly mix 4-maleimide phenol, potassium carbonate and DMF, protect with nitrogen, react for 10-15 min at a rotation speed of 120-150 r / min and a temperature of 50-60℃, then add 3-chloropropyl triethoxysilane, and react for 1-1.5 h to obtain a modifier; uniformly mix carboxyl carbon nanotubes, dicyclohexyl carbodiimide, KH550 and toluene, react for 3-5 h at a rotation speed of 200-300 r / min and a temperature of 20-25℃ to obtain pretreated carbon nanotubes;

[0009] Step A2: disperse the pretreated carbon nanotubes in ethanol, stir at a rotation speed of 200-300 r / min and a temperature of 60-70℃, then add KH550, the modifier and deionized water, and react for 3-5 h to obtain modified carbon nanotubes; uniformly mix the modified carbon nanotubes, 4-formylphenylboronic acid and n-hexane, react for 5-10 min at a rotation speed of 60-80 r / min and a temperature of 70-75℃ to obtain functionalized carbon nanotubes;

[0010] Step A3: mix the reinforcing filler, the functionalized carbon nanotubes, 1,4-benzenediboronic acid and toluene, stir for 6-8 h at a rotation speed of 600-800 r / min and a temperature of 70-80℃ to obtain a composite filler; uniformly mix SBS masterbatch, PP masterbatch, the composite filler, dicumyl peroxide and xylene, react for 2-2.5 h at a rotation speed of 60-80 r / min and a temperature of 130-135℃, then cool to room temperature, remove the filtrate by filtration, melt and extrude the filter cake to obtain a modified resin.

[0011] Further, the molar ratio of 4-maleimide phenol, potassium carbonate and 3-chloropropyl triethoxysilane in step A1 is 1:1.1:1, and the molar ratio of carboxyl on the carboxyl carbon nanotubes, dicyclohexyl carbodiimide and KH550 is 1:1:1.

[0012] Further, the amount ratio of the pretreated carbon nanotubes, ethanol, KH550, the modifier and deionized water in step A2 is 1 g:15 mL:30 mg:30 mg:3 mL, and the molar ratio of amino groups on the modified carbon nanotubes and 4-formylphenylboronic acid is 1:1.

[0013] Further, the mass ratio of the reinforcing filler, the functionalized carbon nanotubes and 1,4-benzenediboronic acid in step A3 is 1:3:3, and the weight ratio of SBS masterbatch, PP masterbatch, the composite filler and dicumyl peroxide is 40-60:130-150:35-55:3-8.

[0014] Further, the reinforcing filler is prepared by the following steps:

[0015] Step B1: mix octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis(ammonia propyl) tetramethyl disiloxane and dimethyl sulfoxide uniformly, protect with nitrogen, under the conditions of rotation speed of 120-150 r / min and temperature of 105-110℃, react for 3-5 h to obtain a diamino polysiloxane, mix the diamino polysiloxane, 4-vinyl benzaldehyde, sodium carbonate and DMF uniformly, under the conditions of rotation speed of 150-200 r / min and temperature of 80-90℃, react for 5-7 h to obtain a modified monomer;

[0016] Step B2: mix sodium dodecyl benzene sulfonate, styrene, acrylonitrile, the modified monomer and DMF uniformly, stir and add potassium persulfate and polytetrafluoroethylene emulsion under the conditions of rotation speed of 200-300 r / min and temperature of 80-85℃, react for 2-3 h, then heat to 90-95℃ and continue to react for 3-5 h to obtain a composite liquid, mix the composite liquid and sulfuric acid solution uniformly, stir and add sulfuric acid solution under the conditions of rotation speed of 600-800 r / min and temperature of 90-95℃, stir for 1-1.5 h, remove the filtrate by filtration to obtain a precursor;

[0017] Step B3: mix the precursor, DOPO and ethanol uniformly, reflux under the conditions of rotation speed of 60-80 r / min and temperature of 78-80℃ for 3-5 h to obtain a modified precursor, mix the modified precursor, 4-vinyl phenyl boronic acid, chloroplatinic acid and n-hexane uniformly, react under the conditions of rotation speed of 120-150 r / min and temperature of 80-85℃ for 2-4 h to obtain a reinforced filler.

[0018] Further, the molar ratio of octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(ammonia propyl) tetramethyl disiloxane in step B1 is 1.4:1:3:2, the molar ratio of the diamino polysiloxane and 4-vinyl benzaldehyde is 1:2, and the amount of sodium carbonate is 1% of the mass of 4-vinyl benzaldehyde.

[0019] Further, the mass ratio of sodium dodecyl benzene sulfonate, styrene, acrylonitrile, the modified monomer and DMF, potassium persulfate and polytetrafluoroethylene emulsion in step B2 is 0.8:45:12:15:200:0.3:20, the solid content of the polytetrafluoroethylene emulsion is 60%, the mass ratio of the composite liquid and sulfuric acid solution is 2:5, and the mass fraction of the sulfuric acid solution is 5%.

[0020] Further, the precursor, DOPO and ethanol in step B3 are used in a ratio of 1g:1.5g:15mL, the molar ratio of Si-H bond on the modified precursor and 4-vinylphenylboronic acid is 1:1, and the amount of chloroplatinic acid is 1 ‰ of the mass of 4-vinylphenylboronic acid.

[0021] The application has the following beneficial effects: the high-flame-retardant insulating power cable disclosed by the application comprises a plurality of conductors arranged in sequence from inside to outside, the surface of the conductors is coated with an insulating layer, the outside of the insulating layer is provided with a wrapping inner liner layer, the wrapping inner liner layer and the insulating layer are filled with a filler, the outside of the wrapping inner liner layer is coated with a protective layer, the outside of the protective layer is coated with a sheath, the sheath is prepared from modified resin, the modified resin is prepared by treating 4-maleimide phenol with potassium carbonate and then reacting with 3-chloropropyl triethoxysilane, so that the hydroxyl group on the 4-maleimide phenol and the chlorine atom site on the 3-chloropropyl triethoxysilane react, a modifier is prepared, carboxyl carbon nanotubes and KH550 are reacted, so that the carboxyl group on the carboxyl carbon nanotube and the amino group on the KH550 react, pretreated carbon nanotubes are prepared, the pretreated carbon nanotubes, KH550 and the modifier are hydrolyzed and condensed, a modified carbon nanotube is prepared, the modified carbon nanotube and 4-formylphenylboronic acid are reacted, the activity of the boronic acid group is reduced under the action of n-hexane, so that the amino group on the modified carbon nanotube and the aldehyde group on the 4-formylphenylboronic acid react, a functionalized carbon nanotube is prepared, the reinforcing filler, the functionalized carbon nanotube and 1,4-benzenediol are reacted, so that the boronic acid groups are grafted with each other, a composite filler is prepared, the SBS master batch, the PP master batch, the composite filler and dicumyl peroxide are reacted, so that the double bonds in the composite filler and the molecules of the SBS master batch and the PP master batch are grafted, and the modified resin is prepared.

[0022] The reinforcing filler is prepared by ring-opening octamethylcyclotetrasiloxane and tetramethylcyclotetrasiloxane as raw materials, and then polymerizing with 1,3-bis (aminopropane alkyl) tetramethyldisiloxane to obtain a diamino polysiloxane, reacting the diamino polysiloxane with 4-vinylbenzaldehyde to make the amino group on the diamino polysiloxane react with the aldehyde group on the 4-vinylbenzaldehyde, and preparing a modified monomer, polymerizing styrene, acrylonitrile and the modified monomer to form a polymer on the surface of polytetrafluoroethylene to form a core-shell structure, and preparing a precursor, reacting the precursor with DOPO to make the C=N bond on the surface of the precursor react with the P-H bond on DOPO, and preparing a modified precursor, and reacting the modified precursor with 4-vinylphenylboronic acid to make the Si-H bond on the modified precursor react with the double bond on the 4-vinylphenylboronic acid, and preparing the reinforcing filler.

[0023] The polytetrafluoroethylene in the composite filler decomposes to generate free radicals when the cable burns, the free radicals can react with oxygen in the air to form a dense fluorine protective film on the surface of the cable, and then isolate oxygen and flame, and the organic phosphorus on the surface will decompose to generate phosphoric acid, metaphosphoric acid and polyphosphoric acid and other substances when heated, the substances have strong dehydration property, can make the surface of the polymer dehydrate and carbonize, and the silicon-nitrogen layer can be formed by compounding with the organic silicon structure, and the doping of boron and nitrogen elements further improves the density of the silicon-carbon layer, forms a multi-layer protective layer on the surface of the cable, effectively avoids the generation of dripping, and the carbon nanotubes can form a network structure, the structure can block oxygen and heat transfer, and improves the flame retardant effect. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0025] Embodiment 1: A high-flame-retardant insulated power cable, comprising a plurality of conductors arranged in sequence from inside to outside, the surface of the conductors being covered with an insulation layer, the outside of the insulation layer being provided with a wrapping inner liner layer, the wrapping inner liner layer being filled with a filler between the insulation layer, the outside of the wrapping inner liner layer being covered with a protective layer, and the outside of the protective layer being covered with a sheath.

[0026] The conductors are tinned copper wires, the wrapping inner liner layer is a mica tape, the filler is a glass fiber, the insulation layer and the protective layer are polyvinyl chloride, the model of the polyvinyl chloride is SG-1, and the sheath is prepared from a modified resin.

[0027] The modified resin is prepared by the following steps:

[0028] Step A1: 4-maleimide phenol, potassium carbonate and DMF are uniformly mixed, nitrogen protection is performed, under the condition that the rotation speed is 120 r / min and the temperature is 50 DEG C, reaction is carried out for 10 min, then 3-chloropropyl triethoxysilane is added, and reaction is carried out for 1 h to prepare a modifier; carboxyl carbon nanotubes, dicyclohexyl carbodiimide, KH550 and toluene are uniformly mixed, under the condition that the rotation speed is 200 r / min and the temperature is 20 DEG C, reaction is carried out for 3 h to prepare pretreated carbon nanotubes.

[0029] Step A2: the pretreated carbon nanotubes were dispersed in ethanol, stirring was carried out at a rotation speed of 200 r / min and a temperature of 60℃, and then KH550, a modifier and deionized water were added, and reaction was carried out for 3h, to obtain modified carbon nanotubes; the modified carbon nanotubes, 4-formylphenylboronic acid and n-hexane were uniformly mixed, stirring was carried out at a rotation speed of 60 r / min and a temperature of 70℃, and then reaction was carried out for 5 min, to obtain functionalized carbon nanotubes;

[0030] Step A3: the reinforcing filler, the functionalized carbon nanotubes, 1,4-benzenediol and toluene were mixed, stirring was carried out at a rotation speed of 600 r / min and a temperature of 70℃ for 6h, to obtain a composite filler; the SBS master batch, the PP master batch, the composite filler, dicumyl peroxide and xylene were uniformly mixed, reaction was carried out at a rotation speed of 60 r / min and a temperature of 130℃ for 2h, then the temperature was lowered to room temperature, the filtrate was removed by filtration, and the filter cake was melt-extruded, to obtain a modified resin.

[0031] The molar ratio of the 4-maleimide phenol, potassium carbonate and 3-chloropropyl triethoxysilane in step A1 was 1:1.1:1, and the molar ratio of the carboxyl on the carboxyl carbon nanotube, dicyclohexyl carbodiimide and KH550 was 1:1:1.

[0032] The amount ratio of the pretreated carbon nanotubes, ethanol, KH550, a modifier and deionized water in step A2 was 1g:15mL:30mg:30mg:3mL, and the molar ratio of the amino group on the modified carbon nanotube and 4-formylphenylboronic acid was 1:1.

[0033] The mass ratio of the reinforcing filler, the functionalized carbon nanotubes and 1,4-benzenediol in step A3 was 1:3:3, and the weight ratio of the SBS master batch, the PP master batch, the composite filler and dicumyl peroxide was 40:130:35:3; the SBS master batch was YH792, and the PP master batch was K8003.

[0034] The reinforcing filler was prepared by the following steps:

[0035] Step B1: octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis (aminopropanalkyl) tetramethyldisiloxane and dimethyl sulfoxide were uniformly mixed, nitrogen protection was carried out, stirring was carried out at a rotation speed of 120 r / min and a temperature of 105℃ for 3h, to obtain a diamino polysiloxane; the diamino polysiloxane, 4-vinylbenzaldehyde, sodium carbonate and DMF were uniformly mixed, stirring was carried out at a rotation speed of 150 r / min and a temperature of 80℃ for 5h, to obtain a modified monomer;

[0036] Step B2: the sodium dodecyl benzene sulfonate, styrene, acrylonitrile, modified monomer and DMF were mixed uniformly, and stirred at a rotation speed of 200 r / min and a temperature of 80℃, and then potassium persulfate and polytetrafluoroethylene emulsion were added and reacted for 2 h, and then the temperature was increased to 90℃ and the reaction was continued for 3 h to obtain a composite solution, and then the composite solution and sulfuric acid solution were mixed uniformly, and stirred at a rotation speed of 600 r / min and a temperature of 90℃, and then the sulfuric acid solution was added and stirred for 1 h, and then the filtrate was removed by filtration to obtain a precursor;

[0037] Step B3: the precursor, DOPO and ethanol were mixed uniformly, and refluxed at a rotation speed of 60 r / min and a temperature of 78℃ for 3 h to obtain a modified precursor, and then the modified precursor, 4-vinylbenzene boronic acid, chloroplatinic acid and n-hexane were mixed uniformly, and reacted at a rotation speed of 120 r / min and a temperature of 80℃ for 2 h to obtain a reinforced filler.

[0038] The molar ratio of octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(ammonia propane alkyl) tetramethyl disiloxane in step B1 is 1.4:1:3:2, the molar ratio of bisamino polysiloxane and 4-vinylbenzaldehyde is 1:2, and the amount of sodium carbonate is 1% of the mass of 4-vinylbenzaldehyde.

[0039] The mass ratio of sodium dodecyl benzene sulfonate, styrene, acrylonitrile, modified monomer and DMF, potassium persulfate and polytetrafluoroethylene emulsion in step B2 is 0.8:45:12:15:200:0.3:20, the solid content of the polytetrafluoroethylene emulsion is 60%, the mass ratio of the composite solution and sulfuric acid solution is 2:5, and the mass fraction of the sulfuric acid solution is 5%.

[0040] The amount ratio of the precursor, DOPO and ethanol in step B3 is 1 g:1.5 g:15 mL, the molar ratio of the Si-H bond on the modified precursor and 4-vinylbenzene boronic acid is 1:1, and the amount of chloroplatinic acid is 1 ‰ of the mass of 4-vinylbenzene boronic acid.

[0041] Embodiment 2, a high flame-retardant insulating power cable, comprising a plurality of conductors arranged in sequence from inside to outside, the surface of the conductor is coated with an insulating layer, the outside of the insulating layer is provided with a wrapping inner liner layer, the wrapping inner liner layer and the insulating layer are filled with a filler, the outside of the wrapping inner liner layer is coated with a protective layer, and the outside of the protective layer is coated with a sheath.

[0042] The conductor is a tinned copper wire, the wrapping inner liner layer is a mica tape, the filler is a glass fiber, the insulating layer and the protective layer are polyvinyl chloride, the type of polyvinyl chloride is SG-1, and the sheath is made of a modified resin.

[0043] The modified resin is made by the following steps:

[0044] Step A1: 4-maleimide phenol, potassium carbonate and DMF were mixed uniformly, protected by nitrogen, reacted for 15 min at a rotation speed of 120 r / min and a temperature of 55℃, then 3-chloropropyl triethoxysilane was added and reacted for 1.5 h to prepare a modifier; carboxyl carbon nanotubes, dicyclohexyl carbodiimide, KH550 and toluene were mixed uniformly, reacted for 4 h at a rotation speed of 200 r / min and a temperature of 25℃ to prepare pretreated carbon nanotubes;

[0045] Step A2: The pretreated carbon nanotubes were dispersed in ethanol, stirred at a rotation speed of 200 r / min and a temperature of 65℃, then KH550, the modifier and deionized water were added and reacted for 4 h to prepare modified carbon nanotubes; the modified carbon nanotubes, 4-formylphenylboronic acid, sodium carbonate and n-hexane were mixed uniformly, reacted for 10 min at a rotation speed of 60 r / min and a temperature of 75℃ to prepare functionalized carbon nanotubes.

[0046] Step A3: The reinforcing filler, the functionalized carbon nanotubes, 1,4-benzenediol and toluene were mixed and stirred at a rotation speed of 600 r / min and a temperature of 75℃ for 7 h to prepare a composite filler; SBS masterbatch, PP masterbatch, the composite filler, dicumyl peroxide and xylene were mixed uniformly, reacted for 2.5 h at a rotation speed of 60 r / min and a temperature of 130℃, then cooled to room temperature, the filtrate was removed by filtration, and the filter cake was melt-extruded to prepare a modified resin.

[0047] The molar ratio of 4-maleimide phenol, potassium carbonate and 3-chloropropyl triethoxysilane in step A1 was 1:1.1:1, and the molar ratio of carboxyl on the carboxyl carbon nanotubes, dicyclohexyl carbodiimide and KH550 was 1:1:1.

[0048] The amount ratio of the pretreated carbon nanotubes, ethanol, KH550, the modifier and deionized water in step A2 was 1 g:15 mL:30 mg:30 mg:3 mL, and the molar ratio of the amino group on the modified carbon nanotubes and 4-formylphenylboronic acid was 1:1.

[0049] The mass ratio of the reinforcing filler, the functionalized carbon nanotubes and 1,4-benzenediol in step A3 was 1:3:3, and the weight ratio of SBS masterbatch, PP masterbatch, the composite filler and dicumyl peroxide was 50:140:45:5; the model of SBS masterbatch was YH792, and the model of PP masterbatch was K8003.

[0050] The reinforcing filler was prepared by the following steps:

[0051] Step B1: octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis(ammonia propyl) tetramethyl disiloxane and dimethyl sulfoxide were mixed uniformly, and then reacted at 120 r / min and 110℃ for 4 h under nitrogen protection to obtain a diamino polysiloxane; the diamino polysiloxane, 4-vinyl benzaldehyde, sodium carbonate and DMF were mixed uniformly, and then reacted at 200 r / min and 80℃ for 6 h to obtain a modified monomer;

[0052] Step B2: sodium dodecyl benzene sulfonate, styrene, acrylonitrile, the modified monomer and DMF were mixed uniformly, and then stirred at 200 r / min and 85℃, and then potassium persulfate and polytetrafluoroethylene emulsion were added and reacted for 2 h; the temperature was increased to 95℃, and then the reaction was continued for 4 h to obtain a composite liquid; the composite liquid and a sulfuric acid solution were mixed uniformly, and then stirred at 600 r / min and 95℃, and then the sulfuric acid solution was added and stirred for 1 h; the filtrate was removed by filtration to obtain a precursor;

[0053] Step B3: the precursor, DOPO and ethanol were mixed uniformly, and then refluxed at 80 r / min and 78℃ for 5 h to obtain a modified precursor; the modified precursor, 4-vinyl phenyl boronic acid, chloroplatinic acid and n-hexane were mixed uniformly, and then reacted at 120 r / min and 85℃ for 3 h to obtain a reinforced filler.

[0054] The molar ratio of octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(ammonia propyl) tetramethyl disiloxane in step B1 was 1.4:1:3:2; the molar ratio of the diamino polysiloxane and 4-vinyl benzaldehyde was 1:2; and the amount of sodium carbonate was 1% of the mass of 4-vinyl benzaldehyde.

[0055] The mass ratio of sodium dodecyl benzene sulfonate, styrene, acrylonitrile, the modified monomer and DMF, potassium persulfate and polytetrafluoroethylene emulsion in step B2 was 0.8:45:12:15:200:0.3:20; the solid content of the polytetrafluoroethylene emulsion was 60%; the mass ratio of the composite liquid and the sulfuric acid solution was 2:5; and the mass fraction of the sulfuric acid solution was 5%.

[0056] The amount ratio of the precursor, DOPO and ethanol in step B3 was 1 g:1.5 g:15 mL; the molar ratio of the Si-H bond on the modified precursor and 4-vinyl phenyl boronic acid was 1:1; and the amount of chloroplatinic acid was 1 ‰ of the mass of 4-vinyl phenyl boronic acid.

[0057] Embodiment 3, a high flame-retardant insulated power cable, comprising a plurality of conductors arranged in sequence from inside to outside, the surface of the conductors being coated with an insulation layer, the outside of the insulation layer being provided with a wrapping inner liner layer, the wrapping inner liner layer being filled with a filler between the insulation layer, the outside of the wrapping inner liner layer being coated with a protective layer, and the outside of the protective layer being coated with a sheath;

[0058] The conductors are tin-plated copper wires, the wrapping inner liner layer is a mica tape, the filler is a glass fiber, the insulation layer and the protective layer are polyvinyl chloride, the model of the polyvinyl chloride is SG-1, and the sheath is prepared from a modified resin.

[0059] The modified resin is prepared by the following steps:

[0060] Step A1: uniformly mix 4-maleimide phenol, potassium carbonate and DMF, protect under nitrogen, react at a rotation speed of 150 r / min and a temperature of 60℃ for 15 min, then add 3-chloropropyl triethoxysilane, and react for 1.5 h to prepare a modifier; uniformly mix carboxyl carbon nanotubes, dicyclohexyl carbodiimide, KH550 and toluene, react at a rotation speed of 300 r / min and a temperature of 25℃ for 5 h to prepare pretreated carbon nanotubes;

[0061] Step A2: disperse the pretreated carbon nanotubes in ethanol, stir at a rotation speed of 300 r / min and a temperature of 70℃, and add KH550, the modifier and deionized water, and react for 5 h to prepare modified carbon nanotubes; uniformly mix the modified carbon nanotubes, 4-formylphenylboronic acid, sodium carbonate and n-hexane, react at a rotation speed of 80 r / min and a temperature of 75℃ for 10 min to prepare functionalized carbon nanotubes;

[0062] Step A3: mix the reinforcing filler, the functionalized carbon nanotubes, 1,4-benzenediboronic acid and toluene, stir at a rotation speed of 800 r / min and a temperature of 80℃ for 8 h to prepare a composite filler; uniformly mix SBS masterbatch, PP masterbatch, the composite filler, dicumyl peroxide and xylene, react at a rotation speed of 80 r / min and a temperature of 135℃ for 2.5 h, then cool to room temperature, remove the filtrate by filtration, melt and extrude the filter cake to prepare the modified resin.

[0063] The molar ratio of 4-maleimide phenol, potassium carbonate and 3-chloropropyl triethoxysilane in step A1 is 1:1.1:1, and the molar ratio of carboxyl on the carboxyl carbon nanotubes, dicyclohexyl carbodiimide and KH550 is 1:1:1.

[0064] The amount ratio of the pretreated carbon nanotubes, ethanol, KH550, modifier and deionized water in step A2 is 1g:15mL:30mg:30mg:3mL, and the molar ratio of the amino group on the modified carbon nanotube and 4-formylphenylboronic acid is 1:1.

[0065] The mass ratio of the reinforcing filler, functionalized carbon nanotube and 1,4-benzenediol in step A3 is 1:3:3, and the weight ratio of the SBS master batch, PP master batch, composite filler and dicumyl peroxide is 60:150:55:8, and the type of the SBS master batch is YH792, and the type of the PP master batch is K8003.

[0066] The reinforcing filler is prepared by the following steps:

[0067] Step B1: uniformly mix octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis(ammonia propyl) tetramethyl disiloxane and dimethyl sulfoxide, protect under nitrogen, react for 5h under the condition of 150r / min rotation speed and 110℃ temperature, prepare diamino polysiloxane, uniformly mix the diamino polysiloxane, 4-vinyl benzaldehyde, sodium carbonate and DMF, react for 7h under the condition of 200r / min rotation speed and 90℃ temperature, prepare modified monomer;

[0068] Step B2: uniformly mix sodium dodecylbenzenesulfonate, styrene, acrylonitrile, modified monomer and DMF, stir and add potassium persulfate and polytetrafluoroethylene emulsion under the condition of 300r / min rotation speed and 85℃ temperature, react for 3h, continue to react for 5h after heating to 95℃, prepare composite liquid, uniformly mix the composite liquid and sulfuric acid solution, stir and add sulfuric acid solution under the condition of 800r / min rotation speed and 95℃ temperature, stir for 1.5h, remove the filtrate by filtration, prepare precursor;

[0069] Step B3: uniformly mix the precursor, DOPO and ethanol, reflux for 5h under the condition of 80r / min rotation speed and 80℃ temperature, prepare modified precursor, uniformly mix the modified precursor, 4-vinyl phenylboronic acid, chloroplatinic acid and n-hexane, react for 4h under the condition of 150r / min rotation speed and 85℃ temperature, prepare reinforcing filler.

[0070] The molar ratio of octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(ammonia propyl) tetramethyl disiloxane in step B1 is 1.4:1:3:2, the molar ratio of the diamino polysiloxane and 4-vinyl benzaldehyde is 1:2, and the amount of sodium carbonate is 1% of the mass of 4-vinyl benzaldehyde.

[0071] The mass ratio of sodium dodecyl benzene sulfonate, styrene, acrylonitrile, modified monomer and DMF, potassium persulfate and polytetrafluoroethylene emulsion in step B2 is 0.8:45:12:15:200:0.3:20, the solid content of the polytetrafluoroethylene emulsion is 60%, and the mass ratio of the composite liquid and the sulfuric acid solution is 2:5, and the mass fraction of the sulfuric acid solution is 5%.

[0072] The use amount ratio of the precursor, DOPO and ethanol in step B3 is 1g:1.5g:15mL, the molar ratio of Si-H bond on the modified precursor and 4-vinylphenylboronic acid is 1:1, and the use amount of chloroplatinic acid is 1 ‰ of the mass of 4-vinylphenylboronic acid.

[0073] Comparative Example 1, compared with Example 1, no reinforcing filler is added, and the remaining steps are the same.

[0074] Comparative Example 2, compared with Example 1, no functionalized carbon nanotube is added, and the remaining steps are the same.

[0075] Comparative Example 3, compared with Example 1, sodium dodecyl benzene sulfonate, styrene, acrylonitrile and DMF are uniformly mixed, stirred at a speed of 200r / min and a temperature of 80℃, and potassium persulfate and polytetrafluoroethylene emulsion are added, and reacted for 2h, then heated to 90℃ and continued to react for 3h to prepare a composite liquid, the composite liquid and a sulfuric acid solution are uniformly mixed, stirred at a speed of 600r / min and a temperature of 90℃, and a sulfuric acid solution is added, and stirred for 1h, then the filtrate is removed by filtration to prepare a product instead of a reinforcing filler, and the remaining steps are the same.

[0076] The modified resins prepared in Examples 1-3 and Comparative Examples 1-3 are used to prepare 130mm×13mm×4mm samples according to the standard of GB / T2408-2021, and the vertical burning grade and flame extinguishing time are detected, and the detection results are shown in Table 1.

[0077] Table 1

[0078]

[0079] From Table 1 above, it can be seen that the present application has good flame retardant effect.

[0080] The above content is only an example and description of the concept of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, as long as they do not deviate from the concept of the present application or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. High flame retardant insulation power cable, characterized by: The conductor comprises a plurality of conductors arranged in sequence from the inside to the outside, wherein the surface of the conductor is covered with an insulating layer, a wrapped inner lining layer is provided outside the insulating layer, a filler is filled between the wrapped inner lining layer and the insulating layer, a protective layer is covered outside the wrapped inner lining layer, and a sheath is covered outside the protective layer; The conductor is tinned copper wire, the inner lining of the wrapping is mica tape, the filler is glass fiber yarn, the insulation layer and protective layer are polyvinyl chloride, and the sheath is made of modified resin; The modified resin is prepared by the following steps: Step A1: 4-maleimidophenol, potassium carbonate, and DMF were uniformly mixed and nitrogen atmosphere was introduced for protection. After the reaction, 3-chloropropyltriethoxysilane was added and the reaction was carried out for 1-1.5 hours to prepare a modifier. Carboxyl carbon nanotubes, dicyclohexylcarbodiimide, KH550, and toluene were mixed and reacted to prepare pretreated carbon nanotubes. Step A2: Dispersing the pretreated carbon nanotubes in ethanol, stirring, and adding KH550, a modifier, and deionized water to react to obtain modified carbon nanotubes, and mixing the modified carbon nanotubes, 4-formylphenylboronic acid, sodium carbonate, and n-hexane to react to obtain functionalized carbon nanotubes; Step A3: The reinforcing filler, functionalized carbon nanotubes, 1,4-phenylenediboronic acid, and toluene are mixed and stirred to prepare a composite filler, and the SBS masterbatch, PP masterbatch, composite filler, dicumyl peroxide, and xylene are mixed and reacted, and then cooled to room temperature. The filtrate is filtered to remove the filtrate, and the filter cake is melt-extruded to prepare a modified resin; The reinforcing filler is prepared by the following steps: Step B1: Octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, and dimethyl sulfoxide are uniformly mixed, and nitrogen is introduced to react to obtain bisaminopolysiloxane. The bisaminopolysiloxane, 4-vinylbenzaldehyde, sodium carbonate, and DMF are mixed and reacted to obtain a modified monomer. Step B2: Sodium dodecylbenzenesulfonate, styrene, acrylonitrile, a modified monomer, and DMF are mixed and stirred, and potassium persulfate and polytetrafluoroethylene emulsion are added to react to obtain a composite liquid. The composite liquid is mixed and stirred with a sulfuric acid solution, and the sulfuric acid solution is added and stirred. The filtrate is filtered to remove the filtrate to obtain a precursor; Step B3: The precursor, DOPO and ethanol are mixed and refluxed to react to obtain a modified precursor, and the modified precursor, 4-vinylphenylboronic acid, chloroplatinic acid and n-hexane are mixed and reacted to obtain a reinforcing filler.

2. The highly flame-retardant insulated power cable according to claim 1, characterized in that: The molar ratio of 4-maleimidophenol, potassium carbonate and 3-chloropropyltriethoxysilane in step A1 is 1:1.1:1, and the molar ratio of carboxyl groups on carboxyl carbon nanotubes, dicyclohexylcarbodiimide and KH550 is 1:1:

1.

3. The highly flame-retardant insulated power cable according to claim 1, characterized in that: The amount ratio of the pretreated carbon nanotubes, ethanol, KH550, modifier and deionized water described in step A2 is 1g:15mL:30mg:30mg:3mL, and the molar ratio of the amino groups on the modified carbon nanotubes to 4-formylphenylboronic acid is 1:

1.

4. The highly flame-retardant insulated power cable according to claim 1, characterized in that: The mass ratio of the reinforcing filler, functionalized carbon nanotubes and 1,4-phenylenediboric acid described in step A3 is 1:3:3, and the weight ratio of SBS masterbatch, PP masterbatch, composite filler and dicumyl peroxide is 40-60:130-150:35-55:3-8.

5. The highly flame-retardant insulated power cable according to claim 1, characterized in that: The molar ratio of octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethylammonium hydroxide and 1,3-bis(aminopropyl)tetramethyldisiloxane described in step B1 is 1.4:1:3:2, and the molar ratio of bisaminopolysiloxane and 4-vinylbenzaldehyde is 1:

2.

6. The highly flame-retardant insulated power cable according to claim 1, characterized in that: The mass ratio of sodium dodecylbenzenesulfonate, styrene, acrylonitrile, modified monomer and DMF, potassium persulfate and polytetrafluoroethylene emulsion described in step B2 is 0.8:45:12:15:200:0.3:20, and the mass ratio of the composite liquid and sulfuric acid solution is 2:

5.

7. The highly flame-retardant insulated power cable according to claim 1, characterized in that: The amount ratio of the precursor, DOPO and ethanol described in step B3 is 1 g:1.5 g:15 mL, and the molar ratio of the Si-H bond on the modified precursor to 4-vinylphenylboronic acid is 1:1.

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