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CN-122011538-A - High-temperature-resistant oil-resistant special cable for electrical equipment

CN122011538ACN 122011538 ACN122011538 ACN 122011538ACN-122011538-A

Abstract

The application relates to the technical field of rubber materials and wire and cable manufacturing, and discloses a high-temperature-resistant oil-resistant special cable for electrical equipment. The prefabricated drying functional powder is prepared by adsorbing epoxidized soybean oil and calcium stearate through fumed silica through a special process. The preparation method comprises a high-temperature mixing induction in-situ polymerization and a low-temperature mixing and vulcanizing two-step method. According to the application, the heat resistance of the matrix is improved by constructing the zinc dimethacrylate ion reinforced network, and the plasticizer is locked by utilizing a physical adsorption and chemical anchoring dual mechanism of the functional powder, so that the hardening and shrinkage problem of the material caused by plasticizer migration in the high Wen Youhuan environment is effectively solved, and the long-term mechanical stability and the processing performance of the cable material are improved.

Inventors

  • XU GUANGYU
  • JIANG RUIYING
  • ZONG XUAN
  • WU QIANG
  • WU MEILING
  • CHEN XILIANG

Assignees

  • 江苏宇久电缆科技有限公司

Dates

Publication Date
20260512
Application Date
20260302

Claims (10)

  1. 1. The special cable for the high-temperature-resistant oil-resistant electrical equipment is characterized by comprising a cable core and a sheath layer coated outside the cable core, wherein the sheath layer is prepared from the following raw materials in parts by weight: 40-60 parts of hydrogenated nitrile rubber; 40-60 parts of ethylene-vinyl acetate rubber; 18-25 parts of zinc dimethacrylate; 0.6-1.5 parts of alpha-methylstyrene dimer; 12-18 parts of prefabricated drying functional powder; 0.4-0.6 part of scorch retarder; 4-6 parts of active magnesium oxide; 2-2.5 parts of anti-aging agent; 3.0-4.0 parts of dicumyl peroxide; 0.8-1.5 parts of triallyl isocyanurate; 3-5 parts of calcium oxide masterbatch.
  2. 2. The high temperature resistant and oil resistant electrical equipment specific cable according to claim 1, wherein the sheath layer is prepared from the following raw materials: 50-55 parts of hydrogenated nitrile rubber; 45-50 parts of ethylene-vinyl acetate rubber; 20-22 parts of zinc dimethacrylate; 0.8-1.2 parts of alpha-methyl styrene dimer; 15 parts of prefabricated drying functional powder.
  3. 3. The high-temperature-resistant and oil-resistant electrical equipment special cable according to claim 1, wherein the prefabricated drying functional powder is prepared from fumed silica, epoxidized soybean oil and calcium stearate, and the weight ratio of the fumed silica to the epoxidized soybean oil to the calcium stearate is 10:20-28:0.3-0.6.
  4. 4. The high-temperature-resistant and oil-resistant electrical equipment special cable according to claim 1, wherein the prefabricated drying functional powder is prepared by the following steps: dispersing calcium stearate in epoxidized soybean oil heated to 55-60 ℃ to form modified oil, then atomizing the modified oil into fumed silica in a high-speed stirring state, maintaining the temperature of the material at 55-65 ℃ by using shearing friction heat, and mixing until the material is in a dry powder state.
  5. 5. The high-temperature-resistant and oil-resistant cable special for electrical equipment according to claim 1, wherein the scorch retarder is 2, 6-di-tert-butyl-4-methylphenol, and the antioxidant is 4,4' -bis (alpha, alpha-dimethylbenzyl) diphenylamine.
  6. 6. A method for preparing a high temperature resistant and oil resistant electrical equipment special cable, which is used for preparing the high temperature resistant and oil resistant electrical equipment special cable according to any one of claims 1 to 5, and is characterized by comprising the following steps: S1, selecting a conductor, extruding an insulating layer on the conductor to obtain an insulating wire core, twisting and filling the insulating wire core into a cable, and obtaining a cable core; S2, adding hydrogenated nitrile rubber, ethylene-vinyl acetate rubber, an anti-aging agent, active magnesium oxide and a scorch retarder into an internal mixer for mixing, then adding zinc dimethacrylate, alpha-methylstyrene dimer and prefabricated drying functional powder, heating and mixing at a constant temperature of 136-145 ℃ to obtain a section A mixing rubber; s3, cooling the section A rubber compound to 65-75 ℃, adding dicumyl peroxide, triallyl isocyanurate and calcium oxide master batch, uniformly mixing, and discharging slices to obtain special rubber compound for the sheath; and S4, extruding the special rubber compound for the sheath obtained in the step S3 on the outer layer of the cable core prefabricated in the step S1, and performing high-temperature vulcanization and crosslinking to obtain a cable finished product.
  7. 7. The method for preparing the high-temperature-resistant and oil-resistant electrical equipment special cable according to claim 6, wherein in the step S1, the pre-drying functional powder adopts the following pretreatment method: Heating epoxidized soybean oil to 55-60 ℃ in a stirring container, adding calcium stearate, stirring and dispersing for 15 minutes to obtain a mixed solution; putting the fumed silica into a high-speed mixer, and spraying the obtained mixed solution through a high-pressure atomizing nozzle at the rotating speed of 1500-1800 rpm; controlling the oil spraying time to be 5-8 minutes, maintaining the temperature to be 55-65 ℃ by utilizing shearing heat, and continuing mixing for 3-5 minutes until discharging after oil spraying is finished.
  8. 8. The method for preparing a high temperature resistant and oil resistant electrical equipment special cable according to claim 6, wherein the process parameters of the step S2 are controlled as follows: After zinc dimethacrylate, alpha-methylstyrene dimer and prefabricated drying functional powder are added, the ram pressure on an internal mixer is raised to 0.6-0.8MPa, the rotating speed of a rotor is raised to 75-95rpm, the temperature of a sizing material is raised to 136-145 ℃ within 2 minutes, and the constant-temperature mixing time is 3-5 minutes.
  9. 9. The method for preparing a high temperature resistant and oil resistant electrical equipment specific cable according to claim 6, wherein the step S3 further comprises: Transferring the section A rubber compound to an open mill, and adjusting the roll spacing to be 1.5mm to perform thin-pass heat dissipation; Adding dicumyl peroxide, triallyl isocyanurate and calcium oxide masterbatch when the temperature of the sizing material is reduced to 65-75 ℃; and then performing triangular bag beating and left and right cutter operation for 5-6 times respectively, adjusting the roll spacing to 4mm, discharging tablets, and curing for 8-24 hours at room temperature.
  10. 10. The method for preparing a high temperature resistant and oil resistant electrical equipment special cable according to claim 6, wherein in the step S4, the crosslinking temperature is controlled to 178-185 ℃, and the steam pressure is controlled to 1.3-1.5MPa.

Description

High-temperature-resistant oil-resistant special cable for electrical equipment Technical Field The invention relates to the technical field of rubber materials and wire and cable manufacturing, in particular to a high-temperature-resistant oil-resistant special cable for electrical equipment. Background In the fields of oil drilling platforms, the periphery of high-power locomotive engines, heavy industrial machinery and the like, an electric connection system of the oil drilling platforms, the periphery of the high-power locomotive engines and the like is in extremely severe working conditions for a long time. The cables used in these locations are not only subjected to sustained high temperature baking, but often contact various types of fuel oil, hydraulic oil or grease. Once the cable sheath and the insulating layer fail in a high-temperature oil-gas environment, the insulation resistance is reduced to cause equipment shutdown, and the short circuit and even fire accidents are caused by heavy weight. The existing rubber cable material mainly selects a base material according to specific emphasis points. Although the oil resistance of the common nitrile rubber is good, the common nitrile rubber is difficult to bear the long-term high temperature of more than 120 ℃, and the carbon chain is easy to generate thermal oxidation aging to cause cracking. To improve heat resistance, industry has begun to move toward the use of ethylene-vinyl acetate rubber (EVM) or hydrogenated nitrile rubber (HNBR). In order to reduce the Mooney viscosity of these high performance rubbers, improve extrusion processability and impart the necessary softness to the cable, prior art solutions have typically incorporated into the formulation a significant amount of liquid plasticizers, such as phthalate esters or polyester based oils. Meanwhile, in order to meet the strength requirement, reinforcing fillers such as carbon black or white carbon black and the like are directly added in the mixing process. However, this conventional modification technique has a defect that the plasticizer has a durability problem, and only physical van der Waals force acts between the liquid small-molecule plasticizer and the rubber macromolecules, so that the plasticizer is easily migrated to the surface of the material and extracted by an external medium under a high Wen Youjin bubble environment. This migration causes the cable jacket to shrink in volume, stress is built in, the hardness of the material increases dramatically and the flexibility is lost, and eventually brittle fracture occurs during equipment vibration. Secondly, the limitation of the processing technology is that the sizing material is easy to slip on the metal wall surface due to the fact that liquid oil is directly added into an internal mixer, and the rotor shearing force is difficult to effectively transfer, so that the filler is unevenly dispersed. This not only reduces the production efficiency, but also causes serious batch fluctuations in the electrical insulation properties of the finished cable. Therefore, the invention provides a high-temperature-resistant oil-resistant special cable for electrical equipment, which solves the defects in the prior art. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a high-temperature-resistant oil-resistant special cable for electrical equipment, which solves the problems that the hardness of the material is increased, the volume is shrunk and the mechanical property is greatly attenuated due to the migration of a plasticizer under the conditions of high temperature and oil medium, and the processing fluidity and the aging-resistant stability are difficult to be simultaneously achieved. In order to achieve the above purpose, the invention is realized by the following technical scheme: The invention provides a high-temperature-resistant oil-resistant special cable for electrical equipment, which comprises a cable core and a sheath layer coated outside the cable core, wherein the sheath layer is prepared from the following raw materials, by weight, 40-60 parts of hydrogenated nitrile rubber, 40-60 parts of ethylene-vinyl acetate rubber, 18-25 parts of zinc dimethacrylate, 0.6-1.5 parts of alpha-methyl styrene dimer, 12-18 parts of prefabricated drying functional powder, 0.4-0.6 part of scorch retarder, 4-6 parts of active magnesium oxide, 2-2.5 parts of anti-aging agent, 3.0-4.0 parts of dicumyl peroxide, 0.8-1.5 parts of triallyl isocyanurate and 3-5 parts of calcium oxide masterbatch. By adopting the technical scheme, the hydrogenated nitrile rubber and the ethylene-vinyl acetate rubber are used as the matrix, and the ionic crosslinking network constructed by combining zinc dimethacrylate in-situ polymerization and the prefabricated drying functional powder have synergistic effect, so that the effects of high temperature resistance, oil swelling resistance and long-term mechanical property stabilit