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CN-121975222-A - High-temperature-resistant halogen-free flame-retardant composite cable and preparation method thereof

CN121975222ACN 121975222 ACN121975222 ACN 121975222ACN-121975222-A

Abstract

The invention discloses a high-temperature-resistant halogen-free flame-retardant composite cable and a preparation method thereof, and belongs to the technical field of cables, wherein the high-temperature-resistant halogen-free flame-retardant composite cable consists of a cable core and a high-temperature-resistant flame-retardant protective sleeve, and the high-temperature-resistant halogen-free flame-retardant protective sleeve comprises, by weight, 50-55 parts of linear low-density polyethylene, 15-20 parts of ethylene-octene copolymer, 8-12 parts of allyl diphenyl phosphinate, 5-8 parts of silanized benzoxazine imine hydroxyacrylate, 0.3-0.6 part of an initiator, 0.5-0.8 part of an antioxidant, 0.5-1.5 parts of a catalyst and 0.5-1.0 part of a processing aid. According to the invention, the high-temperature resistance, halogen-free flame retardance and mechanical property of the cable are synergistically optimized through two monomers of allyl diphenyl phosphinate and silanized benzoxazine imine hydroxyl acrylate and a reasonable stepped curing process.

Inventors

  • WU WEIDONG
  • WEN SHAOHE
  • Lin Chuanghong

Assignees

  • 广东澳通特种电缆有限公司

Dates

Publication Date
20260505
Application Date
20260323

Claims (9)

  1. 1. The high-temperature-resistant halogen-free flame-retardant composite cable is characterized by comprising, by weight, 50-55 parts of linear low-density polyethylene, 15-20 parts of ethylene-octene copolymer, 8-12 parts of allyl diphenyl phosphinate, 5-8 parts of silanized benzoxazine imine hydroxyacrylate, 0.3-0.6 part of initiator, 0.5-0.8 part of antioxidant, 0.5-1.5 parts of catalyst and 0.5-1.0 part of processing aid.
  2. 2. The high-temperature-resistant halogen-free flame-retardant composite cable according to claim 1, wherein the initiator is one or more selected from dicumyl peroxide, dibenzoyl peroxide, bis-tert-butylperoxyisopropyl benzene, di-tert-butyl peroxide and tert-butyl peroxybenzoate, the antioxidant is one or more selected from antioxidant 1010, antioxidant 168, antioxidant 1076 and antioxidant DSTP, the catalyst is one or more selected from dibutyltin dilaurate, dibutyltin diacetate, stannous octoate, tetrabutyl titanate and tetraisopropyl titanate, and the processing aid is one or more selected from stearic acid, zinc stearate, calcium stearate, polyethylene wax, oxidized polyethylene wax and ethylene bis stearamide.
  3. 3. The high temperature resistant halogen-free flame retardant composite cable of claim 1, wherein the preparation method of the allyl diphenyl phosphinate comprises the following steps: Dissolving a mixture of allyl alcohol, diphenyl phosphine oxide, trifluoro methane sulfonic anhydride and dimethyl sulfoxide in an organic solvent, stirring the mixture at room temperature for reaction, and purifying the mixture after the reaction is finished to obtain allyl diphenyl phosphinate.
  4. 4. The high-temperature-resistant halogen-free flame-retardant composite cable according to claim 3, wherein the preparation method is under the protection of inert gas, and the molar ratio of the allyl alcohol to the diphenyl phosphine oxide to the trifluoro methanesulfonic anhydride to the dimethyl sulfoxide is 1 (2.1-2.5): (1.8-2.1).
  5. 5. The high temperature resistant halogen-free flame retardant composite cable of claim 1, wherein the preparation method of the silanized benzoxazine imine hydroxyacrylate comprises the following steps: (1) The synthesis of silanized benzoxazine formaldehyde comprises the steps of mixing vanillin, an aminosilane coupling agent and paraformaldehyde in an organic solvent, heating and stirring a reaction mixture, and purifying after the reaction is finished to obtain silanized benzoxazine formaldehyde: (2) The method comprises the steps of dissolving silanized benzoxazine formaldehyde and 3- ((4- (aminomethyl) benzyl) amino) -2-hydroxypropyl methacrylate in an anhydrous organic solvent, adding p-toluenesulfonic acid, heating and stirring a reaction mixture, and purifying after the reaction is finished to obtain the silanized benzoxazine imine hydroxy acrylate.
  6. 6. The high-temperature-resistant halogen-free flame-retardant composite cable according to claim 5, wherein the reaction condition of the step (1) is under the protection of inert gas and under the anhydrous condition, the aminosilane coupling agent is one or more selected from 3-aminopropyl methyl dimethoxy silane, 3-aminopropyl trimethoxy silane, 3-aminopropyl triethoxy silane and 4-aminobutyl triethoxy silane, and the molar ratio of vanillin to aminosilane coupling agent to paraformaldehyde is 1 (1-1.2): 2.1-2.3.
  7. 7. The high-temperature-resistant halogen-free flame-retardant composite cable according to claim 5, wherein the reaction condition of the step (2) is under the protection of inert gas and under the anhydrous condition, and the mol ratio of the silanized benzoxazine formaldehyde, 3- ((4- (aminomethyl) benzyl) amino) -2-hydroxypropyl methacrylate and p-toluenesulfonic acid is 1 (1.0-1.3) (0.1-0.3).
  8. 8. The method for preparing the high-temperature-resistant halogen-free flame-retardant composite cable according to any one of claims 1 to 7, which is characterized by comprising the following steps: S1, preparing premix, namely uniformly blending allyl diphenyl phosphinate, silanized benzoxazine imine hydroxyl acrylic ester, linear low-density polyethylene, ethylene-octene copolymer, an initiator, an antioxidant and a processing aid in a high-speed mixer to obtain the premix for the cable; s2, extrusion molding, namely adding the premix obtained in the step S1 into a double-screw extruder, melting and plasticizing at the processing temperature, extruding and wrapping the premix on a wire core, and cooling and shaping the premix through a water tank to obtain an uncrosslinked cable blank; s3, catalyst application, namely preparing a catalyst into a catalyst solution, immersing the cable blank in the catalyst solution, performing ultrasonic treatment during the process, taking out, and then drying in vacuum to obtain the cable blank with the surface and shallow layers uniformly attached with the catalyst; S4, step-type heat curing and moisture crosslinking, namely performing temperature programming curing on the cable blank treated by the step S3, namely performing free radical copolymerization curing in a first stage, placing the cable in an oven for treatment, performing benzoxazine ring-opening polymerization in a second stage, raising the temperature, continuing treatment, and performing silane moisture condensation, transferring and placing the cable subjected to heat curing to obtain the high-temperature-resistant halogen-free flame-retardant composite cable.
  9. 9. The preparation method of the high-temperature-resistant halogen-free flame-retardant composite cable according to claim 8, wherein the temperature of the high-speed mixer in the step S1 is 60-90 ℃, the processing temperature of the twin-screw extruder in the step S2 is 100-140 ℃, the mass concentration of the catalyst solution in the step S3 is 5-10%, the ultrasonic treatment condition in the step S3 is 25-35 kHz, the power is 60-80W, the treatment time is 5-10 seconds, the included angle between the ultrasonic probe and the cable is 45 ℃, the vacuum drying condition in the step S3 is 70-80 ℃ and the absolute pressure is 10-20 kPa, the oven temperature in the first stage in the step S4 is 140-160 ℃, the treatment time is 20-60 min, the oven temperature in the second stage in the step S4 is 180-220 ℃, the treatment time is 1-4 h, the environment temperature transferred in the third stage in the step S4 is 50-90 ℃, the relative humidity is 60% -95%, and the standing time is 24-72 h.

Description

High-temperature-resistant halogen-free flame-retardant composite cable and preparation method thereof Technical Field The invention belongs to the technical field of cables, and particularly relates to a high-temperature-resistant halogen-free flame-retardant composite cable and a preparation method thereof. Background With the rapid development of the fields of electric power, communication, new energy and the like, the performance requirements on the cable are increasingly severe, and particularly, the high temperature resistance and flame retardant safety of the cable become core indexes under high temperature, high load and fire hazard environments. The traditional halogen-containing flame-retardant cable can generate a large amount of toxic and corrosive smoke during combustion, so that the traditional halogen-containing flame-retardant cable is phased out, and the development of the high-performance halogen-free flame-retardant cable becomes the main stream direction of the industry. At present, a halogen-free flame-retardant cable taking crosslinked polyethylene as a matrix is an important research point. Crosslinking can significantly improve the heat distortion temperature and mechanical properties of polyethylene. The silane crosslinking technology is widely applied due to simple process and low energy consumption, but the traditional process needs to rely on high energy consumption modes such as external high-temperature cooking or high-pressure steam, and the traditional process is not friendly to a plurality of flame retardants and auxiliaries which are sensitive to water heat. In addition, the conventional additive type halogen-free flame retardant, such as aluminum hydroxide, magnesium hydroxide and the like, needs high filling amount to reach the flame retardant standard, seriously damages the mechanical property and processing fluidity of materials, and is high-efficiency reactive or synergistic flame retardant, such as 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-based derivatives, has low addition amount, but has poor compatibility with polyolefin matrix, has the problems of migration and precipitation after long-term use, and leads to flame retardant property attenuation. In the high-resistant Wen Fangmian, the long-term use temperature of the polymer is usually not more than 90-125 ℃ by simply relying on a crosslinked polyethylene network. To increase the heat resistance level, researchers have attempted to introduce heat resistant resins such as benzoxazines, polyimides, etc., but have generally faced challenges such as poor compatibility with polyolefin blends, narrow processing temperature window, or high cost. Specifically, the prior art has the following outstanding problems to be solved: 1. The properties are difficult to compromise, high flame retardancy often comes at the expense of mechanical properties, in particular toughness and processability. 2. The long-term stability is insufficient, and the physically blended flame retardant is easy to migrate and volatilize, so that the flame retardant performance is reduced with time. 3. The process is complex or has harsh conditions, the realization of high temperature resistance and deep crosslinking often requires multi-step high temperature post treatment or special equipment, the energy consumption is high, and the efficiency is low. 4. The function is single, most modification means are only aimed at a certain performance, such as flame retardance or heat resistance, and lack of systematic molecular structure integration to realize synergistic optimization of multiple performances. Disclosure of Invention In order to overcome the defects in the prior art, the invention provides a high-temperature-resistant halogen-free flame-retardant composite cable and a preparation method thereof. The technical scheme for realizing the purpose of the invention is as follows: The high-temperature-resistant halogen-free flame-retardant composite cable comprises a cable core and a high-temperature-resistant halogen-free flame-retardant protective sleeve, wherein the high-temperature-resistant halogen-free flame-retardant protective sleeve comprises, by weight, 50-55 parts of linear low-density polyethylene, 15-20 parts of ethylene-octene copolymer, 8-12 parts of allyl diphenyl phosphinate, 5-8 parts of silanized benzoxazine imine hydroxyl acrylate, 0.3-0.6 part of an initiator, 0.5-0.8 part of an antioxidant, 0.5-1.5 parts of a catalyst and 0.5-1.0 part of a processing aid. The initiator is selected from one or more of dicumyl peroxide, dibenzoyl peroxide, di-tert-butyl peroxyisopropyl benzene, di-tert-butyl peroxide and tert-butyl peroxybenzoate, the antioxidant is selected from one or more of antioxidant 1010, antioxidant 168, antioxidant 1076 and antioxidant DSTP, the catalyst is selected from one or more of dibutyl tin dilaurate, dibutyl tin diacetate, stannous octoate, tetrabutyl titanate and tetraisopropyl titanate, and the process