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CN-122011776-A - Synergistic reinforced composite insulator silicon rubber and preparation method thereof

CN122011776ACN 122011776 ACN122011776 ACN 122011776ACN-122011776-A

Abstract

The invention belongs to the technical field of high-performance rubber composite materials, and particularly discloses a synergistic reinforced composite insulator silicon rubber. The composite insulator silicone rubber comprises, by weight, 80-120 parts of methyl vinyl silicone rubber raw rubber, 100-130 parts of aluminum hydroxide, 22-32 parts of gas-phase white carbon black, 1.5-3.5 parts of methyl silicone oil, 2.5-7 parts of hydroxyl silicone oil, 1-3 parts of vinyl silicone oil, 1-2.5 parts of a silane coupling agent, 0.2-0.4 part of a vulcanizing agent and 2-4 parts of ferric oxide. According to the invention, through the scientific proportioning and functional coordination of the methyl silicone oil, the hydroxyl silicone oil and the vinyl silicone oil and the proper mixing process, the mechanical property, the electrical insulation property, the processing property and the long-term service stability of the material are obviously improved while the excellent flame retardance is realized. The invention also provides a preparation method of the silicon rubber.

Inventors

  • JIN ZHUAN
  • LIU HAOCHENG
  • NING KAI
  • WANG BOWEN
  • FU ZHIYAO
  • XIE PENGKANG
  • WANG HAINING
  • LIAO ZEMIN
  • ZHOU XIANG

Assignees

  • 国网湖南省电力有限公司防灾减灾中心
  • 国网湖南省电力有限公司
  • 国家电网有限公司

Dates

Publication Date
20260512
Application Date
20260210

Claims (10)

  1. 1. The composite insulator silicone rubber is characterized by comprising, by weight, 80-120 parts of methyl vinyl silicone rubber raw rubber, 100-130 parts of aluminum hydroxide, 22-32 parts of fumed silica, 1.5-3.5 parts of methyl silicone oil, 2.5-7 parts of hydroxyl silicone oil, 1-3 parts of vinyl silicone oil, 1-2.5 parts of a silane coupling agent, 0.2-0.4 part of a vulcanizing agent and 2-4 parts of ferric oxide.
  2. 2. The composite insulator silicone rubber according to claim 1, wherein the vinyl content in the methyl vinyl silicone rubber raw rubber is 0.1-0.2 wt% and the molecular weight thereof is 4 x 10 5 ~9×10 5 .
  3. 3. The composite insulator silicone rubber according to claim 1, wherein the weight ratio of the methyl silicone oil, the hydroxyl silicone oil and the vinyl silicone oil is (0.8-1.5): 2-4): 1.
  4. 4. The composite insulator silicone rubber according to claim 1, wherein the viscosity of the methyl silicone oil is 80 to 500mm 4 /s (25 ℃), the viscosity of the hydroxyl silicone oil is 50 to 500cst (25 ℃) and the viscosity of the vinyl silicone oil is 200 to 800 mpa-s (25 ℃) and the vinyl content is 5.4 to 6.0wt%.
  5. 5. The composite insulator silicone rubber according to claim 1, wherein the specific surface area of the fumed silica is 185-225 m 2 /g, the fumed silica is pre-mixed with the hydroxyl silicone oil before use, the treatment temperature is 40-60 ℃ and the treatment time is 20-40 min.
  6. 6. The composite insulator silicone rubber according to claim 1, wherein the average particle diameter of the aluminum hydroxide is 1 to 3 μm.
  7. 7. The composite insulator silicone rubber of claim 1, wherein the silane coupling agent comprises at least one of vinyltrimethoxysilane or vinyltriethoxysilane.
  8. 8. The composite insulator silicone rubber of claim 1, wherein the vulcanizing agent comprises 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane or bis (2, 4-dichlorobenzoyl peroxide).
  9. 9. The preparation method of the composite insulator silicone rubber according to any one of claims 1 to 8, comprising the following steps: S1, mixing gas-phase white carbon black and hydroxyl silicone oil at a temperature of 40-60 ℃ for 20-40 min to obtain surface modified white carbon black; S2, putting the methyl vinyl silicone rubber raw rubber into an internal mixer, sequentially adding methyl silicone oil and vinyl silicone oil, and mixing, adding surface modified white carbon black, aluminum hydroxide, a silane coupling agent and ferric oxide, and mixing for 30-60 min at 50-70 ℃ under vacuum; s3, cooling the mixed sizing material to below 60 ℃ on an open mill, adding a vulcanizing agent, thinning out the sheet, and carrying out mould pressing vulcanization to obtain the composite insulator silicone rubber.
  10. 10. The method according to claim 9, wherein in the step S3, the vulcanizing condition is that the temperature is 160-180 ℃, the pressure is 8-15 MPa, and the time is 10-20 min.

Description

Synergistic reinforced composite insulator silicon rubber and preparation method thereof Technical Field The invention relates to the technical field of high-performance rubber composite materials, in particular to a synergistic reinforced composite insulator silicon rubber and a preparation method thereof. Background In places with extremely high requirements on fire safety, such as power systems, particularly power stations and substations, the flame retardant performance of external insulation devices such as composite insulators has become a mandatory requirement. Aluminum hydroxide (ATH) is widely used as a high-efficiency and environment-friendly halogen-free flame retardant filler for flame retardant modification of silicone rubber. However, to achieve adequate flame retardant rating (e.g., UL 94V-0), ATH is typically filled in an amount of 120-160phr (per hundred parts of rubber), which presents serious technical challenges to the material in terms of significantly degrading mechanical properties, high levels of rigid inorganic particles severely impede the movement and orientation of the rubber molecular chains, resulting in a sharp decrease in tensile strength, tear strength and elongation at break of the material, and an increase in brittleness. The processability is deteriorated, the viscosity of the sizing material is greatly increased by a high filling system, the mixing energy consumption is increased, the filler is difficult to disperse, and the filler clusters and local stress concentration are easy to occur. The problem of the interface between the filler and the matrix is prominent, that is, a great amount of inorganic filler and the organic silicon rubber matrix have obvious physical and chemical property differences, and the interface bonding strength is low, so that the interface becomes a weak link of stress transmission and a starting point of damage. And the electrical performance and durability risks that filler agglomeration and interface defects are easy to become starting points of charge accumulation and partial discharge under a high-voltage electric field, so that the electric leakage tracking resistance of the material is reduced, and the electric aging and heat aging processes are accelerated. In addition, common methods for improving the performance of highly filled flame retardant silicone rubbers include treating reinforcing filler white carbon black with a single type of silicone oil (e.g., hydroxy silicone oil) to increase dispersibility, and treating inorganic fillers with a silane coupling agent to improve interfacial bonding. However, these approaches tend to focus on solving a single problem. For example, hydroxyl silicone oil can improve white carbon black dispersion, but has limited contribution to reducing system viscosity and improving processing fluidity, and cannot provide long-term hydrophobic recovery capability, and coupling agent treatment can improve interface, but cannot optimize the crosslinked structure of a rubber network. Particularly in the application scene of the composite insulator which needs to meet multiple requirements of high flame retardance, high strength, high insulation, long-term aging resistance and the like, the optimization of the comprehensive performance is difficult to realize by a single modification means. Therefore, development of a new synergistic modification technology is needed to solve the performance contradiction of high-filling flame-retardant silicone rubber from a plurality of layers of systems such as filler dispersion, interface optimization, network structure regulation and control, function giving and the like. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides the synergetic reinforced composite insulator silicon rubber. According to the invention, through the scientific proportioning and functional coordination of the methyl silicone oil, the hydroxyl silicone oil and the vinyl silicone oil and the proper mixing process, the mechanical property, the electrical insulation property, the processing property and the long-term service stability of the material are obviously improved while the excellent flame retardance is realized. The invention also provides a preparation method of the silicon rubber. The invention provides a composite insulator silicon rubber, which comprises, by weight, 80-120 parts of methyl vinyl silicon rubber raw rubber, 100-130 parts of aluminum hydroxide, 22-32 parts of fumed silica, 1.5-3.5 parts of methyl silicone oil, 2.5-7 parts of hydroxyl silicone oil, 1-3 parts of vinyl silicone oil, 1-2.5 parts of a silane coupling agent, 0.2-0.4 part of a vulcanizing agent and 2-4 parts of ferric oxide. The invention constructs a synergistic modification system consisting of three silicone oils with complementary functions. The methyl silicone oil is mainly used as a processing aid and a fun