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CN-122011796-A - Oil-resistant fluorine-containing rubber sealing element and preparation method thereof

CN122011796ACN 122011796 ACN122011796 ACN 122011796ACN-122011796-A

Abstract

The invention discloses an oil-resistant fluorine-containing rubber sealing piece and a preparation method thereof, and belongs to the technical field of fluorine-containing rubber, wherein sodium montmorillonite and graphene oxide are stirred and ultrasonically treated to obtain graphene intercalated montmorillonite powder, the graphene intercalated montmorillonite powder is subjected to hydrothermal loading of CeO 2 /ZrO 2 nano particles and a titanate coupling agent to be subjected to hydrophobic modification to obtain modified composite montmorillonite, and the modified composite montmorillonite and F26-type fluorine-containing rubber are premixed to obtain composite fluorine-containing rubber, and are mixed with gas-phase white carbon black, a plasticizer F-20, active magnesium oxide, calcium hydroxide and phenolic resin SP-1055 and vulcanized in two steps to obtain the oil-resistant fluorine-containing rubber sealing piece; the sealing element has high tensile strength, excellent normal temperature and high temperature oil resistance, high tensile strength heat aging retention rate and good sealing durability.

Inventors

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Assignees

  • 江苏逸晟密封件科技有限公司

Dates

Publication Date
20260512
Application Date
20260327

Claims (10)

  1. 1. The preparation method of the oil-resistant fluorine-containing rubber sealing piece is characterized by comprising the following steps of: Stirring and ultrasonic treating sodium-based montmorillonite and graphene oxide to enable graphene oxide sheets and sodium-based montmorillonite to be intercalated and compounded to obtain graphene intercalated montmorillonite powder; Step two, carrying out hydrothermal loading on CeO 2 /ZrO 2 nano particles on graphene intercalated montmorillonite powder, and then carrying out hydrophobic modification on the graphene intercalated montmorillonite powder by a titanate coupling agent to obtain modified composite montmorillonite; and thirdly, premixing the modified composite montmorillonite and F26 type fluorine-containing rubber to obtain composite fluorine-containing rubber, mixing the composite fluorine-containing rubber with gas-phase white carbon black, a plasticizer F-20, active magnesium oxide, calcium hydroxide and phenolic resin SP-1055, and vulcanizing the mixture in two steps to obtain the oil-resistant fluorine-containing rubber sealing piece.
  2. 2. The preparation method of the oil-resistant fluorine-containing rubber sealing piece according to claim 1, wherein the specific preparation steps of the graphene intercalated montmorillonite powder are as follows: Adding sodium montmorillonite and deionized water into a three-neck flask, magnetically stirring for 20-24h, carrying out ultrasonic treatment for 2-4h to obtain montmorillonite dispersion liquid, adding graphene oxide, continuously stirring for 20-24h, carrying out ultrasonic treatment for 2-4h, transferring into a glass evaporation dish, carrying out air blast drying at 55-65 ℃ to be thick, carrying out ultrasonic treatment for 2-4h, carrying out freeze drying at-70 ℃ below zero and 60 ℃ below zero to be constant weight, grinding, and sieving with a 100-mesh sieve to obtain graphene intercalated montmorillonite powder.
  3. 3. The method for preparing the oil-resistant fluorine-containing rubber sealing piece according to claim 2, wherein the dosage ratio of the sodium montmorillonite to the deionized water to the graphene oxide is 250-350 g/25-40L/250-350 g.
  4. 4. The method for preparing the oil-resistant fluorine-containing rubber sealing element according to claim 1, wherein the specific preparation steps of the modified composite montmorillonite are as follows: Adding the composite montmorillonite into absolute ethyl alcohol, stirring for 10-20min by ultrasonic, adding titanate coupling agent, reacting for 20-30min at 80-90 ℃, filtering, washing the product, and drying to obtain the modified composite montmorillonite.
  5. 5. The method for preparing an oil-resistant fluorine-containing rubber sealing element according to claim 4, wherein the dosage ratio of the composite montmorillonite, the absolute ethyl alcohol and the titanate coupling agent is 400-600g:20-50L:80-120g; The titanate coupling agent is any one of titanate coupling agent HY-201, titanate coupling agent KR-12 and titanate coupling agent KR-TTS.
  6. 6. The method for preparing the oil-resistant fluorine-containing rubber sealing element according to claim 5, wherein the specific preparation steps of the composite montmorillonite are as follows: Adding graphene intercalated montmorillonite powder and deionized water into a round-bottom flask, stirring for 20-24h, adding cerium nitrate and zirconyl nitrate, continuing magnetic stirring for 5-7h, transferring into a reaction kettle, keeping the temperature at 150-160 ℃ for 20-24h, cooling to room temperature, centrifuging for 10-20min, washing, drying to constant weight, transferring into a muffle furnace, roasting for 5-7h at 500-600 ℃, and cooling to room temperature to obtain the composite montmorillonite.
  7. 7. The method for preparing the oil-resistant fluorine-containing rubber sealing element according to claim 6, wherein the dosage ratio of the graphene intercalated montmorillonite powder to deionized water to cerium nitrate to zirconyl nitrate is 400-600 g/20-50L/24-36 g/38.4-46.2 g.
  8. 8. The method for preparing the oil-resistant fluorine-containing rubber sealing element according to claim 1, wherein the specific preparation steps of the composite fluorine-containing rubber are as follows: Adding F26 type fluorine-containing rubber with fluorine content of about 65-70% into ethyl acetate, magnetically stirring for 2-4h, adding modified composite montmorillonite, stirring for 20-30min, ultrasonically stirring for 30-40min, heating to 80-90 ℃, continuously stirring for 1-2h, filtering, and vacuum drying to constant weight to obtain composite fluorine-containing rubber; The dosage ratio of the F26 fluorine-containing rubber, the ethyl acetate and the modified composite montmorillonite is 1000-1200g, 20-22L and 400-480g.
  9. 9. The method for preparing the oil-resistant fluorine-containing rubber sealing member according to claim 1, wherein the specific preparation steps of the oil-resistant fluorine-containing rubber sealing member are as follows: Adjusting an open mill to 50-70 ℃ and an initial roll spacing of 3-4mm, adding composite fluorine-containing rubber, adding gas-phase white carbon black and a plasticizer F-20 after a covered roll generates stacking rubber, uniformly mixing, then adding active magnesium oxide and calcium hydroxide, continuously mixing until uniformity, then adding phenolic resin SP-1055, adjusting the roll spacing to 0.5-1mm, thinning for 4-6 times, adjusting to 2-3mm, discharging sheets, and standing the mixed rubber for 24-48h for curing for later use; Uniformly smearing a release agent on the inner wall of a die cavity, standing for 1-3min to enable the release agent to form a film naturally, adding the rubber compound into the die, vulcanizing for 10-20min at 170-180 ℃ and 15-17MPa, vulcanizing for 10-12h at 200-210 ℃, naturally cooling to room temperature, taking out a part, and trimming to obtain the oil-resistant fluorine-containing rubber sealing part; The mass ratio of the composite fluorine-containing rubber to the gas-phase white carbon black to the plasticizer F-20 to the active magnesium oxide to the calcium hydroxide to the phenolic resin SP-1055 is 1000-1200:150-200:50-80:30-50:60-80:15-25.
  10. 10. An oil-resistant fluororubber seal, characterized in that it is prepared by the method for preparing an oil-resistant fluororubber seal according to any one of claims 1 to 9.

Description

Oil-resistant fluorine-containing rubber sealing element and preparation method thereof Technical Field The invention relates to the technical field of fluorine-containing rubber, in particular to an oil-resistant fluorine-containing rubber sealing piece and a preparation method thereof. Background The fluorine-containing rubber sealing element is a high-end elastic sealing element which is prepared by taking special fluorine rubber bonded with fluorine atoms on carbon atoms of a molecular main chain or a side chain as a base material and vulcanizing and shaping, is specially designed for extreme working conditions of precision chemical equipment such as aerospace, petrochemical industry, automobile engines, fuel oil systems and the like, can be used as a static sealing and dynamic sealing component, effectively blocks media such as fuel oil, lubricating oil, acid-base solvent, strong oxidant, corrosive gas and the like, prevents system leakage and invasion of external impurities, maintains the tightness of equipment cavities and pipelines, and is a core component for guaranteeing continuous and stable operation of equipment under severe working conditions. General purpose rubber such as natural rubber, nitrile rubber, chloroprene rubber and the like is difficult to meet the sealing reliability requirements of extreme working conditions such as high temperature, strong corrosion, high oxidation, inflammable and explosive media, high vacuum, high-speed friction and the like due to the inherent defects of narrow temperature resistance range, weak chemical corrosion resistance, easiness in swelling and degradation by solvents and oxidants, insufficient ozone resistance and oxidation aging resistance, poor vacuum resistance and the like. The fluorine atom has extremely high electronegativity and extremely high C-F chemical bond energy, and the structural modification can break through the performance boundary of general rubber, so that the sealing element has excellent core characteristics of high temperature resistance, chemical corrosion resistance, ageing resistance and the like, and becomes a preferable base material for sealing under extreme working conditions. Through searching, the invention patent with the Chinese patent number of CN114874571A discloses a fluorine-containing rubber material and a preparation method thereof, and a low-Mooney ternary fluorine rubber TECNOFLON P457 is adopted as a matrix, and a specific barium sulfate filler, a methyl fluorosilicone oil plasticizer, a calcium hydroxide and magnesium oxide compound acid absorber, an organic silicone and octadecylamine compound processing aid and a compound vulcanization system consisting of triallyl cyanurate, triallyl isocyanurate and 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane are matched, and the final material is prepared through multistage mixing, parking, recycling and step-by-step vulcanization processes. According to the scheme, the flexural fatigue resistance, elongation at break and low temperature resistance of the fluororubber material are improved, but the adopted barium sulfate filler only forms weak combination of physical cladding with the fluororubber matrix, an anti-aging system and a high-efficiency oil-resistant barrier structure are lacked, the problems that under the complex working conditions of high temperature, ozone coexistence, complex oil phase (such as high-temperature oil immersion and multi-medium mixing) and the like, oxidative degradation of a rubber molecular chain and ozone-induced microcrack generation are easily caused, oil phase molecules are easy to permeate through filler gaps and interface gaps to cause swelling of the material, and the problems of elongation attenuation, oil resistance reduction, service life shortening and the like of a sealing piece prepared from the material are caused after thermal aging. Disclosure of Invention The invention aims to solve the defects that a fluorine-containing rubber sealing piece in the prior art is insufficient in oil resistance and poor in sealing durability in an oil medium environment, particularly a high-temperature oil medium environment, and the mechanical property retention rate is low, the sealing property is easy to attenuate under the synergistic effect of heat aging and high-temperature oil corrosion, and long-term use requirements of severe high-temperature oil sealing working conditions are difficult to meet. The aim of the invention can be achieved by the following technical scheme: the preparation method of the oil-resistant fluorine-containing rubber sealing piece comprises the following steps: Repeatedly stirring and ultrasonically treating sodium-based montmorillonite and graphene oxide to enable graphene oxide sheets to be physically inserted between montmorillonite layers, so as to obtain graphene intercalation montmorillonite powder. And step two, carrying out hydrophobic modification on graphene intercalated montmorillonite powder th