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CN-122011571-A - High-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material and preparation method thereof

CN122011571ACN 122011571 ACN122011571 ACN 122011571ACN-122011571-A

Abstract

The application relates to a high-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material and a preparation method thereof, wherein the high-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material comprises, by mass, 45-55 parts of ethylene-vinyl acetate, 10-15 parts of metallocene linear low-density polyethylene, 15-20 parts of an elastomer, 8-12 parts of a compatilizer, 125-140 parts of a flame retardant, 1-3 parts of a crosslinking aid, 2.5-4 parts of an antioxidant and 2-4 parts of a lubricant. According to the application, through the synergistic effect of the auxiliary crosslinking agent and the antioxidant, the tear resistance of the material is obviously improved while the long-term thermal oxidative aging performance is ensured, and the obtained insulating material has excellent tear resistance, good thermal aging stability and electrical insulation performance. The application relates to a high-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material and a preparation method thereof, wherein the high-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material comprises, by mass, 45-55 parts of ethylene-vinyl acetate, 10-15 parts of metallocene linear low-density polyethylene, 15-20 parts of an elastomer, 8-12 parts of a compatilizer, 125-140 parts of a flame retardant, 1-3 parts of a crosslinking aid, 2.5-4 parts of an antioxidant and 2-4 parts of a lubricant. According to the application, through the synergistic effect of the auxiliary crosslinking agent and the antioxidant, the tear resistance of the material is obviously improved while the long-term thermal oxidative aging performance is ensured, and the obtained insulating material has excellent tear resistance, good thermal aging stability and electrical insulation performance.

Inventors

  • YAO XIN
  • TAO SHENGXI
  • ZHANG YINGLONG
  • LIU XIONGJUN

Assignees

  • 江苏上上电缆集团新材料有限公司
  • 江苏上上电缆集团有限公司

Dates

Publication Date
20260512
Application Date
20260324

Claims (10)

  1. 1. The high-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material is characterized by comprising the following components in parts by weight: 45-55 parts of ethylene-vinyl acetate, 10-15 parts of metallocene linear low density polyethylene, 15-20 parts of elastomer, 8-12 parts of compatilizer, 125-140 parts of flame retardant, 1-3 parts of auxiliary cross-linking agent, 2.5-4 parts of antioxidant and 2-4 parts of lubricant.
  2. 2. The high-tear-resistance irradiation crosslinking low-smoke halogen-free flame retardant polyolefin insulation material as claimed in claim 1, wherein the vinyl acetate monomer content in the ethylene-vinyl acetate is 18-40wt%, and the melt mass flow rate is 2.0-6.0g/10min (190 ℃ per 2.16 kg).
  3. 3. The high tear radiation crosslinked low smoke zero halogen flame retardant polyolefin insulation material of claim 1, wherein the metallocene linear low density polyethylene has a density of 0.916-0.926g/cm 3 and a melt mass flow rate of 1.0-4.0g/10min (190 ℃ C./2.16 kg).
  4. 4. The high-tear-resistance irradiation crosslinking low-smoke zero-halogen flame-retardant polyolefin insulation material as claimed in claim 1, wherein the elastomer is a polyolefin elastomer, the density is 0.86-0.90g/cm 3 , and the melt flow rate is 1.0-3.0g/10min (190 ℃ per 2.16 kg).
  5. 5. The high-tear-resistance irradiation crosslinking low-smoke halogen-free flame retardant polyolefin insulating material as claimed in claim 1, wherein the compatilizer comprises any one of polyolefin elastomer grafted maleic anhydride, polyethylene grafted maleic anhydride and ethylene propylene diene monomer grafted maleic anhydride, and the grafting rate is 0.6-1.2%.
  6. 6. The high-tear-resistance irradiation crosslinking low-smoke halogen-free flame retardant polyolefin insulation material according to claim 1, wherein the flame retardant comprises any one or two of aluminum hydroxide and magnesium hydroxide, and the D50 of the flame retardant is 0.7-1.5 mu m.
  7. 7. The high-tear-resistance irradiation crosslinking low-smoke halogen-free flame retardant polyolefin insulation material according to claim 1, wherein the auxiliary crosslinking agent comprises hydroxyl-terminated hyperbranched polyester, the number of hydroxyl groups of which is 10-25/mol, and the molecular weight of which is 1000-3000g/mol.
  8. 8. The high-tear-resistance irradiation crosslinking low-smoke halogen-free flame retardant polyolefin insulating material according to claim 1, wherein the antioxidant comprises a main antioxidant, an auxiliary antioxidant and a metal ion passivating agent, and the mass ratio of the main antioxidant to the auxiliary antioxidant to the metal ion passivating agent is (1-1.5): 1.5-2.5): 0.2-0.5.
  9. 9. A high tear radiation crosslinking low smoke halogen free flame retardant polyolefin insulation material as defined in any one of claims 1-8, characterized by the steps of: Weighing various materials for standby, putting the materials into an internal mixer for internal mixing, discharging after the internal mixing is finished, adding the materials into a double-screw mixing, extruding and granulating by a single screw after the mixing, and finally drying and cooling to obtain material particles, namely the high-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material.
  10. 10. The method for preparing the high-tear-resistance irradiation crosslinking low-smoke halogen-free flame retardant polyolefin insulating material according to claim 9, wherein the thickness of the material particles is 2-4mm.

Description

High-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material and preparation method thereof Technical Field The application relates to the field of high polymer insulating materials, in particular to a high-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material and a preparation method thereof. Background The irradiation crosslinking low-smoke halogen-free flame retardant polyolefin insulating material is widely applied to electrical systems in the fields of rail transit, new energy automobiles, ships, power transmission and the like due to excellent heat resistance, flame retardance and electrical insulation performance. With the continuous improvement of the system integration level, the insulating material faces a more severe service environment, namely, on one hand, the insulating material needs to bear high-temperature impact and long-term thermal oxidation aging caused by high-current on-off, and on the other hand, the insulating material needs to pass through narrow holes or contact sharp structures in the installation and laying processes, so that higher requirements are put on the tear resistance of the material. In the existing material system, irradiation crosslinking polyolefin is commonly used at 125 ℃ and 150 ℃ heat resistance grades, and silicon rubber is selected as the higher heat resistance grade. However, silicone rubber is expensive, not resistant to chemical solvents, and has poor tear resistance, which makes it difficult to meet long-term reliable operating requirements under complex conditions. Although irradiation crosslinking can improve the heat resistance and mechanical strength of the material, the influence on tensile strength and tear resistance is not synchronous. Tear resistance is more dependent on the energy dissipation capacity of the molecular chains at the crack tip, while highly crosslinked networks limit the mobility of the molecular chains, making the material "tough" to "brittle". In addition, high doses of irradiation can also initiate molecular chain scission, further compromising tear strength. Therefore, excellent tear resistance needs to be balanced between the degree of crosslinking and toughness. In the irradiation crosslinking system, an auxiliary crosslinking agent is often added to improve the crosslinking efficiency, but excessive use or irradiation dose is too high to form an excessively dense crosslinking network, so that the tear resistance is seriously reduced. Meanwhile, the insulating material for the high-voltage electric system generally needs to meet the long-term thermal oxidative aging requirement of more than 3000 hours, more antioxidants are needed to be added, but the traditional hindered phenol main antioxidants can inhibit crosslinking, so that the irradiation dose is forced to be increased, the chain breakage is aggravated, and the tear resistance is further weakened. In the prior art, although the disclosed patent relates to a tearing-resistant halogen-free flame retardant material, the metallocene polyethylene is mainly used for high hardness and low tearing resistance, or the compatibility is improved by introducing polar rubber, the insulation volume resistivity is obviously reduced, the electrical safety is affected, and no effective tearing-resistant measured data are provided. Therefore, the irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material which has excellent tear resistance, meets the long-term thermal oxidative aging requirement and has high electrical safety is developed, and has important practical significance. Disclosure of Invention In order to improve the tear resistance of the insulating material, the application provides a high tear resistance irradiation crosslinking low smoke halogen-free flame retardant polyolefin insulating material and a preparation method thereof. In a first aspect, the application provides a high-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material, which adopts the following technical scheme: The high-tear-resistance irradiation crosslinking low-smoke halogen-free flame-retardant polyolefin insulating material comprises the following components in parts by mass: 45-55 parts of ethylene-vinyl acetate, 10-15 parts of metallocene linear low density polyethylene, 15-20 parts of elastomer, 8-12 parts of compatilizer, 125-140 parts of flame retardant, 1-3 parts of auxiliary cross-linking agent, 2.5-4 parts of antioxidant and 2-4 parts of lubricant. By adopting the technical scheme, the ethylene-vinyl acetate is used as a basic matrix to provide flexibility and processability, the metallocene linear low-density polyethylene improves the heat resistance and electrical insulation of a system, the elastomer enhances the tearing resistance and the low-temperature toughness, the polyolefin matrix fo