Self-lubricating material for tailgate support rod bellows

Abstract

The application discloses a kind of tailgate support rod bellows self-lubricating materials, with ternary ethylene-propylene rubber 100 parts as matrix, with N550 carbon black, N774 carbon black, paraffin oil, active zinc oxide, stearic acid, antioxidant, composite processing aid, composite protective wax, resin type processing aid and porous oil-loaded composite self-lubricating component 8-15 parts, etc. The material is made of raw materials. Through the synergistic effect of porous oil-loaded component and polytetrafluoroethylene lubricating phase, the interface frictional resistance of bellows and tailgate support rod sleeve assembly is reduced, the two are easily fitted, the manual oiling operation before assembly is reduced, the sliding friction coefficient under specified test conditions is reduced, and the mechanical properties and heat aging resistance of the rubber matrix are considered.

Description

Technical Field

[0001] This invention relates to the field of rubber composite materials technology, and specifically to a self-lubricating material for tailgate strut corrugated pipes. Background Technology

[0002] The bellows in the tailgate strut is a key protective and sealing component in the automotive electric tailgate strut system. Its main function is to protect the motor and transmission mechanism inside the strut from dust, moisture, and mechanical damage, while allowing the strut to deform freely during extension and retraction. During the assembly of the bellows with the tailgate strut, the bellows needs to be fitted over the strut. When the frictional resistance at the contact interface is high, the bellows may not smoothly align with the tailgate strut, usually requiring manual lubrication to assist assembly. After assembly, repeated friction occurs between the inner and outer walls of the bellows and between the bellows and the strut body during the reciprocating motion of the tailgate opening and closing. Over time, this may lead to wear, abnormal noise, and seal failure.

[0003] In existing technologies, tailgate strut bellows typically use ethylene propylene diene monomer (EPDM) rubber as the base material, primarily utilizing EPDM's excellent weather resistance, ozone resistance, and heat aging resistance. However, EPDM rubber itself has a high coefficient of friction, which can easily generate significant interfacial frictional resistance when the bellows is fitted with the tailgate strut, making it difficult for the bellows to fit smoothly. After assembly, stick-slip can easily occur under dry friction conditions, leading to abnormal noise and wear. To improve assembly lubrication performance, existing technologies often employ two solutions: one is to manually apply grease during bellows assembly, but this method adds a manual oiling step, making it difficult to control the amount and uniformity of oil application, and the grease may migrate, leak, and age during long-term use, resulting in insufficient lubrication durability; the other is to directly add solid lubricants such as polytetrafluoroethylene micro powder, molybdenum disulfide, or graphite to the rubber formulation, but the dispersion state and amount of solid lubricants can affect the frictional and mechanical properties of the rubber material, and improper use may lead to agglomeration.

[0004] Furthermore, directly adding liquid lubricants such as silicone oil to the rubber formulation may reduce the mechanical properties and vulcanization crosslinking density of the rubber, affecting the performance of the bellows. Therefore, how to reduce the interfacial frictional resistance when assembling the bellows and tailgate struts, while taking into account the mechanical properties and heat aging resistance of the EPDM rubber matrix, to facilitate the fitting of the two and reduce the reliance on manual oiling, and at the same time reduce the sliding friction coefficient during use to alleviate abnormal noise and wear, is a technical problem that needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to address the problem of high resistance during the assembly of the tailgate strut bellows and tailgate strut, which typically requires manual oiling. This invention provides a self-lubricating material for the tailgate strut bellows. This material reduces the interfacial frictional resistance during the assembly of the bellows and tailgate strut by introducing a porous, oil-carrying composite self-lubricating component into a EPDM rubber matrix. This facilitates the assembly and reduces reliance on manual oiling. Simultaneously, under the test conditions specified in this application, it reduces the material's sliding friction coefficient, helping to alleviate abnormal noise and wear during use, while also considering the mechanical properties, processing performance, and heat aging resistance of the rubber matrix.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: a self-lubricating material for tailgate strut corrugated pipes, comprising, by weight, the following components: 100 parts EPDM rubber, 30-45 parts N550 carbon black, 15-25 parts N774 carbon black, 20-35 parts paraffin oil, 2.5-4.5 parts active zinc oxide, 1.0-2.0 parts stearic acid, 0.8-1.5 parts 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, 1.0-2.0 parts anhydrous fatty alcohol and fatty acid ester composite processing aid, 1.0-2.0 parts natural fatty acid calcium salt and amide ester wax composite processing aid, 1.0-2.0 parts paraffin wax and microcrystalline wax composite protective wax, and resin-based... Processing aids 1.0-2.5 parts, porous oil-carrying composite self-lubricating component 8-15 parts, pre-dispersed sulfur masterbatch with sulfur mass fraction of 75-80% 1.0-1.8 parts, TMTD-80GN pre-dispersion accelerator 0.2-0.5 parts, DPTT-70GE pre-dispersion accelerator 0.2-0.5 parts, ZDBC-80GE pre-dispersion accelerator 0.2-0.5 parts, ZDTP-70 pre-dispersion accelerator 0.2-0.5 parts, ZBEC-70GE pre-dispersion accelerator 0.2-0.5 parts, CBS-80PE pre-dispersion accelerator 0.4-0.8 parts, and MBTS-75GE pre-dispersion accelerator 0.4-0.8 parts.

[0007] Furthermore, the porous oil-carrying composite self-lubricating component is made from the following raw materials in parts by weight: 100 parts mesoporous silica, 65-90 parts dimethyl silicone oil, 20-35 parts polytetrafluoroethylene micro powder, and 8-15 parts thermoplastic acrylic modified silicone resin.

[0008] Further, through the above technical solution, the porous oil-loaded composite self-lubricating component is a composite particle formed by mixing mesoporous silica loaded with dimethyl silicone oil, thermoplastic acrylic modified silicone resin, and polytetrafluoroethylene micro powder; wherein, the dimethyl silicone oil is located in the pores of the mesoporous silica, the thermoplastic acrylic modified silicone resin is located between the oil-loaded mesoporous silica and the polytetrafluoroethylene micro powder and plays a physical bonding role, and the polytetrafluoroethylene micro powder is distributed in the interior and / or surface of the composite particle.

[0009] Furthermore, the preparation method of the porous oil-carrying composite self-lubricating component, based on the above technical solution, includes the following steps: A1. Dry the mesoporous silica at 115-125℃ and a gauge pressure of -0.095-0.085MPa for 2-4 hours to ensure that the moisture content of the mesoporous silica is not higher than 0.5%.

[0010] A2. Add the dried mesoporous silica to a closed stirring device. Under the conditions of 75-90℃, 100-200r / min and gauge pressure of -0.085--0.060MPa, add dimethyl silicone oil dropwise over 15-30 minutes. After the addition is complete, continue stirring for 30-60 minutes. Then, under continuous stirring, restore the pressure to normal and continue stirring for 20-40 minutes to obtain oil-loaded mesoporous silica.

[0011] A3. Heat the oil-carrying mesoporous silica to 100-115℃, add thermoplastic acrylic-modified silicone resin with a softening point of 80-100℃, and mix at 40-60 r / min for 2-5 min to soften the thermoplastic acrylic-modified silicone resin and wet the surface of the oil-carrying mesoporous silica. Then add polytetrafluoroethylene micro powder and continue mixing for 5-10 min. After cooling to below 35℃, pulverize and classify by airflow, controlling the median particle size D50 to be 8-20 μm. Then remove large agglomerates through a 60-100 mesh sieve to obtain the porous oil-carrying composite self-lubricating component.

[0012] Furthermore, the EPDM rubber described above is a Keltan 10660C type EPDM rubber. This EPDM rubber serves as the matrix material, providing rubber elasticity, weather resistance, and heat aging resistance. This EPDM rubber has a high ethylene content, giving the material good tensile strength and filler filling capacity; a moderate ethylene-based norbornene content ensures sufficient vulcanization crosslinking density; and the Mooney viscosity range ensures good processing fluidity.

[0013] Furthermore, through the above technical solution, the mass ratio of N550 carbon black to N774 carbon black is 1.5-2.5:1. The N550 carbon black and N774 carbon black are reinforcing fillers. N550 carbon black is a fast-extrusion furnace black, imparting high tensile strength and stress at a given elongation to the rubber compound; N774 carbon black is a non-polluting, high-elongation semi-reinforcing furnace black, imparting good elasticity, low heat generation, and low compression set to the rubber compound.

[0014] Furthermore, through the above technical solution, the mass ratio of the paraffin oil to the total amount of N550 carbon black and N774 carbon black is 0.38-0.62:1. The paraffin oil is a paraffin-based processing oil, used as a plasticizer to improve the processing performance and softness of the rubber compound, and also has good compatibility with EPDM rubber.

[0015] Furthermore, through the above technical solution, the active zinc oxide serves as a vulcanization activator, improving the vulcanization rate and crosslinking density. The stearic acid serves as a vulcanization activating aid, forming a soluble zinc soap in conjunction with zinc oxide to promote the vulcanization reaction. The 4,4′-bis(α,α-dimethylbenzyl)diphenylamine serves as an antioxidant, providing resistance to thermo-oxidative aging and flexural fatigue.

[0016] Furthermore, the anhydrous fatty alcohol and fatty acid ester composite processing aid described above is an AFLUX42 type processing aid.

[0017] Furthermore, the natural fatty acid calcium salt and amide ester wax composite processing aid described above is an AFLUX16 type processing aid.

[0018] Furthermore, through the above technical solution, the paraffin wax and microcrystalline wax composite protective wax is ANTILUX654 type protective wax with a solidification point of 62-67℃.

[0019] Furthermore, through the above technical solution, the resin-type processing aid is a hydrocarbon tackifying resin for rubber with a softening point of 90-115℃.

[0020] Furthermore, through the above technical solution, the median particle size D50 of the mesoporous silica is 4-10 μm.

[0021] Furthermore, through the above technical solution, the dimethyl silicone oil is a trimethylsiloxy-terminated polydimethylsiloxane with a kinematic viscosity of 1000-5000 mmHg at 25°C. 2 / s.

[0022] Furthermore, through the above technical solution, the median particle size D50 of the polytetrafluoroethylene micro powder is 2-6 μm.

[0023] Furthermore, through the above technical solution, the thermoplastic acrylic modified silicone resin is solid at room temperature and has a softening point of 80-100℃.

[0024] Furthermore, through the above technical solution, the volume of the dimethyl silicone oil is calculated based on its measured density at 25°C, and is not greater than the total pore volume of the mesoporous silica measured by nitrogen adsorption method.

[0025] Furthermore, through the above technical solution, the total mass fraction of the predispersed sulfur masterbatch, TMTD-80GN predispersing accelerator, DPTT-70GE predispersing accelerator, ZDBC-80GE predispersing accelerator, ZDTP-70 predispersing accelerator, ZBEC-70GE predispersing accelerator, CBS-80PE predispersing accelerator and MBTS-75GE predispersing accelerator is 2.8-5.9 parts.

[0026] Through the above technical solution, the sulfur mass fraction of the pre-dispersed sulfur masterbatch is 75-80%, and the pre-dispersion method is used to improve the uniform dispersion of sulfur in the rubber compound. The TMTD-80GN pre-dispersion accelerator, DPTT-70GE pre-dispersion accelerator, ZDBC-80GE pre-dispersion accelerator, ZDTP-70 pre-dispersion accelerator, ZBEC-70GE pre-dispersion accelerator, CBS-80PE pre-dispersion accelerator, and MBTS-75GE pre-dispersion accelerator constitute a composite vulcanization accelerator system. Among them, CBS and MBTS are sulfenamide and thiazole accelerators, respectively; TMTD and DPTT are thiuram accelerators and can participate in sulfur supply; ZDBC and ZBEC are zinc dithiocarbamate accelerators; and ZDTP is zinc dialkyl dithiocarbamate accelerator. The values ​​in the above pre-dispersion accelerator models represent their nominal effective ingredient mass fraction, and the actual effective ingredient content is subject to the corresponding batch product qualification certificate.

[0027] This invention also provides a method for preparing a self-lubricating material for a tailgate strut bellows, comprising the following steps: S1. A porous oil-carrying composite self-lubricating component is prepared according to the preparation method specified above.

[0028] S2. Set the filling coefficient of the internal mixer to 0.68-0.75 and the rotor speed to 45-60 r / min. Add EPDM rubber and plasticize for 60-120s. Then add N550 carbon black, N774 carbon black, active zinc oxide, stearic acid, 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, anhydrous fatty alcohol and fatty acid ester composite processing aid, natural fatty acid calcium salt and amide ester wax composite processing aid, paraffin wax and microcrystalline wax composite protective wax, resin-type processing aid, and 50-60% of the total amount of paraffin oil. Mix for 90-150s.

[0029] S3. When the temperature of the rubber compound in the internal mixer reaches 105-115℃, add the remaining paraffin oil and porous oil-carrying composite self-lubricating component, continue mixing for 60-120s, and discharge the rubber when the temperature of the rubber compound reaches 125-135℃ to obtain a first-stage compound.

[0030] S4. Cool the first section of the compound to below 50°C and let it stand for 4-12 hours. Then add it to a mixer and add pre-dispersed sulfur masterbatch, TMTD-80GN pre-dispersion accelerator, DPTT-70GE pre-dispersion accelerator, ZDBC-80GE pre-dispersion accelerator, ZDTP-70 pre-dispersion accelerator, ZBEC-70GE pre-dispersion accelerator, CBS-80PE pre-dispersion accelerator and MBTS-75GE pre-dispersion accelerator in sequence at 50-80°C. Mix for 2-4 minutes and discharge the compound when the temperature is not higher than 100°C to obtain the self-lubricating material for the tailgate strut corrugated pipe.

[0031] S5. Place the tailgate strut bellows in a bellows mold with a self-lubricating material, and mold and vulcanize it for 8-12 minutes at 165-175℃ and 8-12MPa. After demolding, cool it to 30-40℃ to obtain the tailgate strut bellows.

[0032] Through the above technical solution, further, in step S3, the porous oil-carrying composite self-lubricating component is added in two parts, with the two addition amounts being 55-65% and 35-45% of the total mass of the porous oil-carrying composite self-lubricating component, respectively, and the time interval between the two additions being 30-60s.

[0033] A tailgate strut bellows is provided, wherein the tailgate strut bellows is made by compression molding and vulcanization of the aforementioned tailgate strut bellows with a self-lubricating material; the porous oil-loaded composite self-lubricating component is dispersed in the rubber matrix of the tailgate strut bellows, the porous oil-loaded composite self-lubricating component includes mesoporous silica loaded with dimethyl silicone oil, thermoplastic acrylic modified silicone resin, and polytetrafluoroethylene micro powder; a standard vulcanized test piece is prepared by compression molding and vulcanizing the same batch of unvulcanized rubber material used to prepare the tailgate strut bellows at 170°C and 10MPa for 10 minutes, the Shore A hardness measured according to ASTM D2240 is 55-65, the tensile strength measured according to ASTM D412 is not less than 8MPa, and the elongation at break is not less than 400%; the Mooney viscosity measured at 100°C in ML(1+4) of the same batch of unvulcanized rubber material is 20-28MU.

[0034] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention loads dimethyl silicone oil into mesoporous silica channels, forming composite particles with the oil-loaded mesoporous silica, thermoplastic acrylic-modified silicone resin, and polytetrafluoroethylene (PTFE) micropowder. The PTFE micropowder provides solid lubrication, while the loaded dimethyl silicone oil provides liquid lubrication. Together, they reduce the interfacial frictional resistance when the inner wall of the bellows mates with the outer surface of the tailgate strut, facilitating smooth bellows assembly and reducing manual oiling before assembly. Its low-friction characteristics also reduce abnormal noise and wear during use.

[0035] 2. Mesoporous silica is a rigid porous particle. Thermoplastic acrylic modified silicone resin can wet and physically bind oil-loaded mesoporous silica and polytetrafluoroethylene micro powder above its softening temperature, which helps the composite particles disperse in the rubber matrix.

[0036] 3. Loading dimethyl silicone oil at least partially within the mesoporous silica channels helps reduce the impact of silicone oil being added directly to the rubber formulation in a free liquid state on the properties of the vulcanized rubber; at the same time, 4,4′-bis(α,α-dimethylbenzyl)diphenylamine antioxidant and paraffin wax and microcrystalline wax composite protective wax are used to improve the material's resistance to thermo-oxidative aging and ozone protection.

[0037] 4. The present invention uses pre-dispersed sulfur masterbatch and pre-dispersed accelerator, which helps the vulcanizing compounding agents to disperse in the rubber compound; the compound processing aid is used to improve the flowability of the rubber compound and the dispersibility of fillers during the mixing process.

[0038] 5. The thermoplastic acrylic-modified silicone resin softens at the temperature in step A3 and wets and physically binds the oil-loaded mesoporous silica and polytetrafluoroethylene micropowder. Attached Figure Description

[0039] Figure 1 This is a comparison of the Fourier transform infrared spectra of the porous oil-carrying composite self-lubricating component and its constituent raw materials in Example 1 of the present invention.

[0040] Figure 2 The TEM image shows the porous oil-carrying composite self-lubricating component of Example 1 of the present invention, along with its interface structure. Among them: (a) a magnified TEM image of the transition zone between the mesoporous silica and resin enrichment in the composite particles; (b) a TEM image of the overall morphology of the composite particles and the outer edge region of the particles.

[0041] Figure 3 The image shows the SEM morphology of the corrugated pipe cross-section of the vulcanized tailgate strut in Embodiment 1 of the present invention and the EDS surface distribution diagrams of C, O, Si, F, Zn, and S elements. Among them: (a) low-magnification cross-sectional SEM image; (b) high-magnification cross-sectional SEM image; (c) C element; (d) O element; (e) Si element; (f) F element; (g) Zn element; (h) S element surface distribution map; Figure 4 This is a physical image of the present invention. Detailed Implementation

[0042] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1: This embodiment provides a self-lubricating material for the tailgate strut bellows, the formulation of which is as follows: 100 parts of ethylene propylene diene monomer (Keltan 10660C type, ethylene mass fraction 56%, ethylene-1,2-bis(norbornene) mass fraction 6.5%, Mooney viscosity at 150℃ ML(1+8) 66MU)

[0044] 37.5 parts of N550 carbon black.

[0045] 20 parts of N774 carbon black.

[0046] 27.5 parts paraffin oil.

[0047] 3.5 parts of active zinc oxide.

[0048] 1.5 parts stearic acid.

[0049] 1.15 parts of 4,4′-bis(α,α-dimethylbenzyl)diphenylamine.

[0050] 1.5 parts of AFLUX42 processing aid (i.e., anhydrous fatty alcohol and fatty acid ester composite processing aid).

[0051] 1.5 parts of AFLUX16 type processing aid (i.e., a composite processing aid of natural fatty acid calcium salt and amide ester wax).

[0052] 1.5 parts of ANTILUX654 protective wax (i.e., a composite protective wax of paraffin and microcrystalline wax, with a solidification point of 65℃).

[0053] 1.75 parts of a hydrocarbon tackifying resin for rubber with a softening point of 100℃.

[0054] 11.5 parts of porous oil-carrying composite self-lubricating component.

[0055] 1.4 parts of predispersed sulfur masterbatch with a sulfur mass fraction of 78%.

[0056] 0.35 parts of TMTD-80GN pre-dispersion accelerator.

[0057] 0.35 parts of DPTT-70GE pre-dispersion accelerator.

[0058] 0.35 parts of ZDBC-80GE pre-dispersion accelerator.

[0059] 0.35 parts of ZDTP-70 pre-dispersion accelerator.

[0060] 0.35 parts of ZBEC-70GE pre-dispersion accelerator.

[0061] 0.6 parts of CBS-80PE pre-dispersion accelerator.

[0062] MBTS-75GE pre-dispersion accelerator 0.6 parts.

[0063] The porous oil-carrying composite self-lubricating component is made from the following raw materials in parts by weight: mesoporous silica (median particle size D50 of 7 μm, BET specific surface area of ​​230 m²). 2 100 parts of dimethyl silicone oil (kinematic viscosity at 25℃ is 3000 mm³ / g, pore volume is 1.0 mL / g); 2 77.5 parts of polytetrafluoroethylene micro powder (median particle size D50 is 4μm) and 11.5 parts of thermoplastic acrylic modified silicone resin (softening point is 90℃).

[0064] The preparation method of the porous oil-carrying composite self-lubricating component includes the following steps: A1. Dry the mesoporous silica at 120℃ and a gauge pressure of -0.090MPa for 3 hours to ensure that the moisture content of the mesoporous silica is not higher than 0.5% (measured using a halogen moisture analyzer), thus obtaining dried mesoporous silica.

[0065] A2. Add the dried mesoporous silica to a closed stirring device. Under the conditions of 82℃, 150r / min and gauge pressure of -0.075MPa, add dimethyl silicone oil dropwise over 22 minutes. After the addition is complete, continue stirring for 45 minutes. Then, under continuous stirring, restore to normal pressure and continue stirring for 30 minutes to obtain oil-loaded mesoporous silica.

[0066] A3. Heat the oil-carrying mesoporous silica to 108°C, add thermoplastic acrylic modified silicone resin, and mix at 50 r / min for 3 min to soften the resin and wet the surface of the oil-carrying mesoporous silica. Then add polytetrafluoroethylene micro powder and continue mixing for 8 min. After cooling to below 30°C, pulverize and classify by airflow, and then remove large agglomerates through an 80-mesh sieve to obtain a porous oil-carrying composite self-lubricating component with a median particle size D50 of 14 μm.

[0067] The preparation method of the self-lubricating material for the tailgate strut bellows includes the following steps: S1. Prepare a porous oil-carrying composite self-lubricating component according to the above steps A1-A3.

[0068] S2. Set the filling factor of the internal mixer to 0.72 and the rotor speed to 52 r / min. Add EPDM rubber and plasticize for 90s. Then add N550 carbon black, N774 carbon black, active zinc oxide, stearic acid, 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, AFLUX42 processing aid, AFLUX16 processing aid, ANTILUX654 protective wax, hydrocarbon tackifying resin for rubber, and 55% (i.e., 15.1 parts) of the total amount of paraffin oil. Mix for 120s.

[0069] S3. When the temperature of the rubber compound in the internal mixer reaches 110℃, add the remaining paraffin oil (12.4 parts) and the porous oil-carrying composite self-lubricating component (11.5 parts). Add the porous oil-carrying composite self-lubricating component in two parts. The first part is 7.0 parts (accounting for 61% of the total mass), and the second part is 4.5 parts (accounting for 39% of the total mass) after an interval of 45s. Continue mixing for 90s. When the temperature of the rubber compound reaches 130℃, discharge the rubber to obtain a first-stage compound.

[0070] S4. Cool the first section of the compound to 45°C and let it stand for 8 hours. Then add it to a mixer and add pre-dispersed sulfur masterbatch, TMTD-80GN pre-dispersion accelerator, DPTT-70GE pre-dispersion accelerator, ZDBC-80GE pre-dispersion accelerator, ZDTP-70 pre-dispersion accelerator, ZBEC-70GE pre-dispersion accelerator, CBS-80PE pre-dispersion accelerator and MBTS-75GE pre-dispersion accelerator in sequence at 65°C. Mix for 3 minutes and discharge the compound when the temperature reaches 95°C to obtain the self-lubricating material for the tailgate strut bellows.

[0071] S5. Place the tailgate strut bellows in a bellows mold with self-lubricating material, and mold and vulcanize it for 10 minutes at 170°C and 10MPa. After demolding, cool it to 35°C to obtain the tailgate strut bellows.

[0072] Depend on Figure 1 It can be seen that mesoporous silica exists at a depth of approximately 3200–3600 cm. -1 A broad absorption band is observed at approximately 1080 cm⁻¹, caused by surface silanol groups and adsorbed water. -1 A strong Si-O-Si antisymmetric stretching vibration peak appears at approximately 800 cm⁻¹, and continues at this peak. -1 and 460cm -1 The characteristic peaks of Si-O-Si symmetrical stretching and bending vibrations appear nearby; dimethyl silicone oil shows a peak at approximately 2960 cm⁻¹. -1 A CH stretching vibration peak of -CH3 appears at approximately 1260 cm⁻¹. -1 A Si-CH3 deformation vibration peak appears at approximately 1090–1020 cm⁻¹. -1 and 800cm -1The surrounding area exhibits characteristic absorptions of the silicon-oxygen backbone Si-O-Si and Si-C / -Si(CH3)2, respectively; polytetrafluoroethylene micropowder shows characteristic absorptions at approximately 1200 cm⁻¹. -1 and 1150cm -1 A distinct double peak of -CF2- antisymmetric and symmetric stretching vibrations appears nearby; the acrylic-modified silicone resin retains approximately 1000–1100 cm⁻¹. -1 In addition to the Si-O-Si absorption at approximately 1720–1740 cm⁻¹, there is also absorption at approximately 1720–1740 cm⁻¹. -1 The characteristic peak of the C=O group of the ester carbonyl group in the acrylate group appears at [location missing]. The porous oil-carrying composite self-lubricating component also retains a peak at approximately 2960 cm⁻¹. -1 CH peak, approximately 1730 cm -1 The ester carbonyl peak, approximately 1200–1000 cm⁻¹ -1 Strong absorptions of overlapping CF and Si-O-Si within the range and approximately 800 cm⁻¹ -1 The presence of characteristic peaks of silicon-containing structures in the vicinity, and the absence of any obvious new independent absorption peaks, indicates that dimethyl silicone oil, polytetrafluoroethylene, and acrylic acid-modified silicone resin have all been introduced into the mesoporous silica system. The composite process mainly involves pore adsorption, interfacial coating, and physical bonding, rather than a large-scale new covalent chemical reaction.

[0073] Depend on Figure 2 As can be seen, the porous oil-carrying composite self-lubricating component of Example 1 exhibits an irregular composite particle morphology. The dark gray area with high electron density and internal granular and loose porous texture can be attributed to mesoporous silica. There is a transitional area with lighter grayness and uneven thickness on its outer side, which can correspond to the enriched area of ​​thermoplastic acrylic modified silicone resin. Irregular sheet-like or blocky low-contrast areas can be seen on the local outer edge.

[0074] Depend on Figure 3 As can be seen, the cross-section of the vulcanized corrugated pipe in Example 1 exhibits a continuous rubber matrix morphology. Tear ridges, wrinkled fracture textures, and several irregular micron-sized particles are visible within the matrix. No large-scale through-holes or severe interfacial debonding are observed around the particles. Carbon (C) is continuously distributed throughout the field of view, primarily originating from EPDM, carbon black, and organic components. O and Si elements are enriched in some irregular particle regions with largely overlapping spatial outlines, corresponding to silicon- and oxygen-containing mesoporous silica and organosilicon resin components. F elements are mainly distributed locally on the surface or edges of some Si / O-enriched particles, corresponding to polytetrafluoroethylene (PTFE) micropowder enrichment regions. Zn and S elements are distributed with relatively small signals in the rubber matrix, originating from zinc oxide, zinc-containing accelerators, sulfur, and sulfur-containing accelerators, respectively. These SEM-EDS results support the coexistence of Si / O-containing particle regions and F-enriched regions in the vulcanized rubber cross-section, but are not used to prove the type of chemical bonds, crosslinking density, or directional migration of composite particles on the inner surface of the corrugated pipe.

[0075] Example 2: This embodiment provides a self-lubricating material for tailgate strut bellows. Referring to the formulation and preparation method in Example 1, the amounts of each component are adjusted as follows: 30 parts N550 carbon black, 15 parts N774 carbon black, 20 parts paraffin oil, 2.5 parts active zinc oxide, 1.0 part stearic acid, 0.8 parts 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, 1.0 part AFLUX42 processing aid, 1.0 part AFLUX16 processing aid, 1.0 part ANTILUX654 protective wax, and rubber... 1.0 part of hydrocarbon tackifying resin, 8 parts of porous oil-carrying composite self-lubricating component, 1.0 part of predispersed sulfur masterbatch, 0.2 parts of TMTD-80GN predispersing accelerator, 0.2 parts of DPTT-70GE predispersing accelerator, 0.2 parts of ZDBC-80GE predispersing accelerator, 0.2 parts of ZDTP-70 predispersing accelerator, 0.2 parts of ZBEC-70GE predispersing accelerator, 0.4 parts of CBS-80PE predispersing accelerator, and 0.4 parts of MBTS-75GE predispersing accelerator.

[0076] The porous oil-loaded composite self-lubricating component comprises: 100 parts mesoporous silica, 65 parts dimethyl silicone oil, 20 parts polytetrafluoroethylene micro powder, and 8 parts thermoplastic acrylic modified silicone resin. The preparation parameters for the porous oil-loaded composite self-lubricating component are adjusted as follows: Step A1: drying temperature 115℃, gauge pressure -0.095MPa, drying time 2h; Step A2: stirring temperature 75℃, rotation speed 100r / min, gauge pressure -0.085MPa, addition time 15min, continued stirring for 30min, and stirring at normal pressure for 20min; Step A3: heating to 100℃, mixing rotation speed 40r / min, resin mixing for 2min, PTFE mixing for 5min, air jet milling and classification, and then passing through a 60-mesh sieve.

[0077] In step S2, the internal mixer filling coefficient is 0.68, the rotor speed is 45 r / min, the plasticizing time is 60 s, the mixing time is 90 s, and 55% (11 parts) of paraffin oil is added first. In step S3, when the rubber compound temperature is 105℃, the remaining paraffin oil and self-lubricating components are added (in two batches, 55% and 45%, with an interval of 30 s), and the mixture is mixed for 60 s and discharged at 125℃. In step S4, the mixture is cooled to below 50℃ and left to stand for 4 hours, then the vulcanizing agent is added at 50℃, and the mixture is mixed for 2 min and discharged at 95℃. In step S5, the mixture is vulcanized at 165℃ and 8MPa for 12 min and then cooled to 40℃.

[0078] The median particle size D50 of the porous oil-carrying composite self-lubricating component is 10 μm.

[0079] Example 3: This embodiment provides a self-lubricating material for the tailgate strut bellows. Referring to the formulation and preparation method in Example 1, the amounts of each component are adjusted as follows: 45 parts N550 carbon black, 25 parts N774 carbon black, 35 parts paraffin oil, 4.5 parts active zinc oxide, 2.0 parts stearic acid, 1.5 parts 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, 2.0 parts AFLUX42 processing aid, 2.0 parts AFLUX16 processing aid, 2.0 parts ANTILUX654 protective wax, and rubber hydrocarbon. The composition includes 2.5 parts of tackifying resin, 15 parts of porous oil-carrying composite self-lubricating component, 1.8 parts of predispersed sulfur masterbatch, 0.5 parts of TMTD-80GN predispersing accelerator, 0.5 parts of DPTT-70GE predispersing accelerator, 0.5 parts of ZDBC-80GE predispersing accelerator, 0.5 parts of ZDTP-70 predispersing accelerator, 0.5 parts of ZBEC-70GE predispersing accelerator, 0.8 parts of CBS-80PE predispersing accelerator, and 0.8 parts of MBTS-75GE predispersing accelerator.

[0080] The porous oil-loaded composite self-lubricating component comprises: 100 parts mesoporous silica, 90 parts dimethyl silicone oil, 35 parts polytetrafluoroethylene micro powder, and 15 parts thermoplastic acrylic modified silicone resin. The preparation parameters for the porous oil-loaded composite self-lubricating component are adjusted as follows: Step A1: drying temperature 125℃, gauge pressure -0.085MPa, drying time 4h; Step A2: stirring temperature 90℃, rotation speed 200r / min, gauge pressure -0.060MPa, addition time 30min, continued stirring 60min, and atmospheric pressure stirring 40min; Step A3: heating to 115℃, mixing rotation speed 60r / min, resin mixing 5min, PTFE mixing 10min, air jet milling and classification, and then passing through a 100-mesh sieve.

[0081] In step S2, the internal mixer filling coefficient is 0.75, the rotor speed is 60 r / min, the plasticizing time is 120 s, the mixing time is 150 s, and 60% (21 parts) of paraffin oil is added first. In step S3, when the rubber compound temperature is 115℃, the remaining paraffin oil and self-lubricating components are added (in two batches, 65% and 35%, with an interval of 60 s), and the mixture is mixed for 120 s and discharged at 135℃. In step S4, the mixture is cooled to below 50℃ and left to stand for 12 h, then the vulcanizing agent is added at 80℃, and the mixture is mixed for 4 min and discharged at 100℃. In step S5, the mixture is vulcanized at 175℃ and 12 MPa for 8 min and then cooled to 30℃.

[0082] The median particle size D50 of the porous oil-carrying composite self-lubricating component is 18 μm.

[0083] Example 4: This embodiment provides a self-lubricating material for tailgate strut bellows. Referring to the formulation and preparation method in Example 1, the BET specific surface area of ​​mesoporous silica is adjusted to 180 m².2 The pore volume was adjusted to 0.8 mL / g, the median particle size D50 was adjusted to 4 μm, and the kinematic viscosity of dimethyl silicone oil at 25 °C was adjusted to 1000 mm. 2 / s, the median particle size D50 of polytetrafluoroethylene micro powder was adjusted to 2μm, the softening point of thermoplastic acrylic modified silicone resin was adjusted to 80℃, and other aspects remained the same as in Example 1.

[0084] Comparative Example 1: This comparative example provides a rubber material for a tailgate strut corrugated pipe. Referring to the formulation and preparation method in Example 1, the porous oil-carrying composite self-lubricating component is omitted (i.e., the amount of porous oil-carrying composite self-lubricating component added is 0 parts), and everything else remains the same as in Example 1.

[0085] Comparative Example 2: This comparative example provides a rubber material for a tailgate strut corrugated pipe. Referring to the formulation and preparation method in Example 1, the porous oil-carrying composite self-lubricating component is replaced with an equal mass (11.5 parts) of polytetrafluoroethylene micro powder, which is directly added to the rubber formulation. Everything else remains the same as in Example 1.

[0086] Comparative Example 3: This comparative example provides a rubber material for a tailgate strut bellows. Referring to the formulation and preparation method in Example 1, the porous oil-carrying composite self-lubricating component is replaced with an equal mass (11.5 parts) of dimethyl silicone oil, which is directly added to the rubber formulation (added in step S3). Everything else remains the same as in Example 1.

[0087] Comparative Example 4: This comparative example provides a self-lubricating material for tailgate strut bellows. Referring to the formulation and preparation method in Example 1, when preparing the porous oil-loaded composite self-lubricating component, mesoporous silica is replaced with an equal mass of precipitated silica (BET specific surface area of ​​150 m²). 2 / g, pore volume is 0.4mL / g), and everything else is the same as in Example 1.

[0088] Comparative Example 5: This comparative example provides a self-lubricating material for tailgate strut bellows. Referring to the formulation and preparation method in Example 1, when preparing the porous oil-loaded composite self-lubricating component, polytetrafluoroethylene micro powder is omitted (that is, the mass part of polytetrafluoroethylene micro powder is adjusted to 0 parts, and the mesoporous silica is increased to 127.5 parts to maintain the consistency of the total mass), and everything else is the same as in Example 1.

[0089] Comparative Example 6: This comparative example provides a self-lubricating material for tailgate strut bellows. Referring to the formulation and preparation method in Example 1, when preparing the porous oil-carrying composite self-lubricating component, the thermoplastic acrylic modified silicone resin is omitted (that is, the mass part of the thermoplastic acrylic modified silicone resin is adjusted to 0 parts, and the mesoporous silica is increased to 111.5 parts to maintain the consistency of the total mass), the resin coating and mixing process in step A3 is omitted, and the oil storage core is directly mixed with polytetrafluoroethylene micro powder. Everything else is the same as in Example 1.

[0090] Comparative Example 7: This comparative example provides a self-lubricating material for tailgate strut bellows. Referring to the formulation and preparation method in Example 1, the amount of porous oil-carrying composite self-lubricating component added is adjusted to 4 parts (lower than the range of 8-15 parts in claim 1), and the rest remains the same as in Example 1.

[0091] Comparative Example 8: This comparative example provides a self-lubricating material for tailgate strut bellows. Referring to the formulation and preparation method in Example 1, the amount of porous oil-carrying composite self-lubricating component added is adjusted to 20 parts (higher than the range of 8-15 parts in claim 1), and the rest remains the same as in Example 1.

[0092] Comparative Example 9: This comparative example provides a self-lubricating material for tailgate strut bellows. Referring to the formulation and preparation method in Example 1, when preparing the porous oil-loaded composite self-lubricating component, the vacuum drying treatment in step A1 is omitted (the mesoporous silica is directly used in step A2 without drying), and everything else remains the same as in Example 1.

[0093] Comparative Example 10: This comparative example provides a self-lubricating material for tailgate strut bellows. Referring to the formulation and preparation method in Example 1, in step S3, the porous oil-carrying composite self-lubricating component is added simultaneously with fillers such as carbon black in step S2 (instead of being added in two parts when the temperature reaches 105-115°C in step S3). Everything else remains the same as in Example 1.

[0094] Performance testing: The performance of the self-lubricating material used in the tailgate strut bellows prepared in Examples 1-4 and Comparative Examples 1-10 was tested. The materials from each example and comparative example were molded and vulcanized at 170°C and 10 MPa for 10 min according to the conditions in step S5 to prepare standard test specimens. The coefficient of friction, as an indirect indicator of the trend of interfacial frictional resistance when the bellows material is in contact with the metal rod, was used to assist in evaluating the smoothness of the fitting assembly.

[0095] 1. Shore A Hardness: The hardness of the vulcanized specimen was determined according to ASTM D2240, "Standard Test Methods for Rubber Properties - Shore Hardness," using a Shore A hardness tester. The specimen test surface was flat, and sufficient spacing was maintained between each test point.

[0096] 2. Tensile strength and elongation at break: Tested according to ASTM D412, "Standard Test Method for Tensile Properties of Vulcanized Rubber and Thermoplastic Elastomers". Vulcanized rubber sheets were cut into standard dumbbell-shaped specimens and subjected to tensile testing on a material testing machine. The maximum tensile stress and elongation at break were recorded as tensile strength and elongation at break, respectively.

[0097] 3. Assembly Interface Friction Coefficient: The test was conducted according to GB / T3960-2016 "Test Method for Sliding Friction and Wear of Plastics". Rubber samples prepared under the above vulcanization conditions were bonded and fixed onto a rigid sample holder. A No. 45 steel wheel was used for grinding, with a normal load of 20 N and a wheel speed of 200 r / min, for continuous friction for 30 min. The friction coefficient was continuously recorded during the test, and the average value after the friction coefficient entered the stable stage was taken as the test result. The stable stage refers to the fluctuation range of the friction coefficient within 10 consecutive minutes not exceeding ±10% of the average value of that stage. The test result is used to characterize the changing trend of interfacial frictional resistance when different materials are fitted with a metal rod, and is not equivalent to the actual assembly force of the entire bellows.

[0098] 4. Mooney viscosity: Tested according to ASTM D1646, "Standard Test Methods for Viscosity, Stress Relaxation and Pre-curing Properties of Rubber". The test temperature is 100℃, a large rotor is used, and the test conditions are ML(1+4), that is, after the sample is preheated for 1 min, the rotor rotates continuously for 4 min, and the Mooney viscosity value is read at the 4th minute, in MU.

[0099] 5. Performance Change Rate After Hot Air Aging: The samples were subjected to hot air aging treatment according to GB / T3512-2014 "Accelerated Aging and Heat Resistance Tests of Vulcanized Rubber or Thermoplastic Rubber in Hot Air". The aging temperature was 150℃, and the aging time was 72 hours. After aging, the samples were removed from the aging chamber and placed at 23±2℃ until the sample temperature stabilized. The tensile strength of the aged samples was then tested according to ASTM D412. The tensile strength change rate after hot air aging was calculated using the following formula: Tensile strength change rate after hot air aging = (Tensile strength after aging - Tensile strength before aging) ÷ Tensile strength before aging × 100%.

[0100] Performance test data are shown in Table 1.

[0101] Table 1. Performance test data for examples and comparative examples Table 1 shows that, under the unified vulcanization and testing conditions described in this application, Examples 1-4 achieved a balance between the coefficient of friction at the assembly interface, mechanical properties, Mooney viscosity, and the rate of change in tensile strength after hot air aging. Compared with Comparative Example 1, which did not contain the composite self-lubricating component, Examples 1-4 showed a lower coefficient of friction at the assembly interface during the stable phase, indicating that it helps reduce the interface frictional resistance when the bellows material and the metal rod are fitted together, thereby improving assembly smoothness and reducing reliance on manual oiling; this indicator is a comparison result under standardized grinding conditions and is not equivalent to the actual assembly force of the entire bellows. Comparative Examples 2 and 3 used polytetrafluoroethylene micropowder or dimethyl silicone oil with the same total mass as the composite self-lubricating component in Example 1, and are not considered as comparisons of equal effective component dosages. Comparative Examples 4-6 also involve changes in carrier properties, component omissions, or supplementary mass; their results are used for comparison of the corresponding overall schemes and are not used alone to quantitatively attribute a specific structural parameter. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A self-lubricating material for the corrugated pipe of a tailgate strut, characterized in that, By weight, it comprises the following components: 100 parts EPDM rubber, 30-45 parts N550 carbon black, 15-25 parts N774 carbon black, 20-35 parts paraffin oil, 2.5-4.5 parts active zinc oxide, 1.0-2.0 parts stearic acid, 0.8-1.5 parts 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, 1.0-2.0 parts anhydrous fatty alcohol and fatty acid ester composite processing aid, 1.0-2.0 parts natural fatty acid calcium salt and amide ester wax composite processing aid, 1.0-2.0 parts paraffin and microcrystalline wax composite protective wax, 1.0-2.5 parts resin-based processing aid, and porous oil-carrying type... The composition includes 8-15 parts of a composite self-lubricating component, 1.0-1.8 parts of a pre-dispersed sulfur masterbatch with a sulfur mass fraction of 75-80%, 0.2-0.5 parts of TMTD-80GN pre-dispersion accelerator, 0.2-0.5 parts of DPTT-70GE pre-dispersion accelerator, 0.2-0.5 parts of ZDBC-80GE pre-dispersion accelerator, 0.2-0.5 parts of ZDTP-70 pre-dispersion accelerator, 0.2-0.5 parts of ZBEC-70GE pre-dispersion accelerator, 0.4-0.8 parts of CBS-80PE pre-dispersion accelerator, and 0.4-0.8 parts of MBTS-75GE pre-dispersion accelerator. The porous oil-carrying composite self-lubricating component is made from the following raw materials in parts by weight: 100 parts mesoporous silica, 65-90 parts dimethyl silicone oil, 20-35 parts polytetrafluoroethylene micro powder, and 8-15 parts thermoplastic acrylic modified silicone resin. The porous oil-loaded composite self-lubricating component is a composite particle formed by mixing mesoporous silica loaded with dimethyl silicone oil, thermoplastic acrylic modified silicone resin, and polytetrafluoroethylene micro powder; wherein, the dimethyl silicone oil is located in the pores of the mesoporous silica, the thermoplastic acrylic modified silicone resin is located between the oil-loaded mesoporous silica and the polytetrafluoroethylene micro powder and plays a physical bonding role, and the polytetrafluoroethylene micro powder is distributed in the interior and / or surface of the composite particle.

2. The self-lubricating material for the tailgate strut corrugated pipe according to claim 1, characterized in that, The preparation method of the porous oil-carrying composite self-lubricating component includes the following steps: A1. Dry the mesoporous silica at 115-125℃ and a gauge pressure of -0.095-0.085MPa for 2-4 hours, so that the moisture content of the mesoporous silica is not higher than 0.5% by mass. A2. Add the dried mesoporous silica to a closed stirring device. Under the conditions of 75-90℃, 100-200r / min and gauge pressure of -0.085--0.060MPa, add dimethyl silicone oil dropwise over 15-30 minutes. After the addition is complete, continue stirring for 30-60 minutes. Then, under continuous stirring, restore the pressure to normal and continue stirring for 20-40 minutes to obtain oil-loaded mesoporous silica. A3. Heat the oil-carrying mesoporous silica to 100-115℃, add thermoplastic acrylic-modified silicone resin with a softening point of 80-100℃, and mix at 40-60 r / min for 2-5 min to soften the thermoplastic acrylic-modified silicone resin and wet the surface of the oil-carrying mesoporous silica. Then add polytetrafluoroethylene micro powder and continue mixing for 5-10 min. After cooling to below 35℃, pulverize and classify by airflow, controlling the median particle size D50 to be 8-20 μm. Then remove large agglomerates through a 60-100 mesh sieve to obtain the porous oil-carrying composite self-lubricating component.

3. The self-lubricating material for the tailgate strut corrugated pipe according to claim 1, characterized in that, The EPDM rubber is Keltan 10660C type EPDM rubber.

4. The self-lubricating material for the tailgate strut corrugated pipe according to claim 1, characterized in that, The mass ratio of N550 carbon black to N774 carbon black is 1.5-2.5:1; The mass ratio of the paraffin oil to the total amount of N550 carbon black and N774 carbon black is 0.38-0.62:

1.

5. The self-lubricating material for the tailgate strut corrugated pipe according to claim 1, characterized in that, The anhydrous fatty alcohol and fatty acid ester composite processing aid is AFLUX42 type processing aid; The natural fatty acid calcium salt and amide ester wax composite processing aid is AFLUX16 type processing aid; The paraffin wax and microcrystalline wax composite protective wax is ANTILUX654 type protective wax with a freezing point of 62-67℃. The resin-type processing aid is a hydrocarbon tackifying resin for rubber with a softening point of 90-115℃.

6. The self-lubricating material for the tailgate strut corrugated pipe according to claim 1, characterized in that, The median particle size D50 of the mesoporous silica is 4-10 μm; The dimethyl silicone oil is a trimethylsiloxy-terminated polydimethylsiloxane with a kinematic viscosity of 1000-5000 mmHg at 25°C. 2 / s; The median particle size D50 of the polytetrafluoroethylene micro powder is 2-6 μm; The thermoplastic acrylic-modified silicone resin is solid at room temperature and has a softening point of 80-100℃. The volume of the dimethyl silicone oil is calculated based on its measured density at 25°C, and is not greater than the total pore volume of the mesoporous silica measured by nitrogen adsorption.

7. The self-lubricating material for the tailgate strut corrugated pipe according to claim 1, characterized in that, The total mass fraction of the predispersed sulfur masterbatch, TMTD-80GN predispersive accelerator, DPTT-70GE predispersive accelerator, ZDBC-80GE predispersive accelerator, ZDTP-70 predispersive accelerator, ZBEC-70GE predispersive accelerator, CBS-80PE predispersive accelerator, and MBTS-75GE predispersive accelerator is 2.8-5.9 parts.

8. A method for preparing a self-lubricating material for the tailgate strut bellows according to any one of claims 1-7, characterized in that, Includes the following steps: S1. A porous oil-carrying composite self-lubricating component is prepared according to the preparation method defined in claim 2; S2. Set the filling coefficient of the internal mixer to 0.68-0.75 and the rotor speed to 45-60 r / min. Add EPDM rubber and plasticize for 60-120s. Then add N550 carbon black, N774 carbon black, active zinc oxide, stearic acid, 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, anhydrous fatty alcohol and fatty acid ester composite processing aid, natural fatty acid calcium salt and amide ester wax composite processing aid, paraffin wax and microcrystalline wax composite protective wax, resin-type processing aid, and 50-60% of the total amount of paraffin oil. Mix for 90-150s. S3. When the temperature of the rubber compound in the internal mixer reaches 105-115℃, add the remaining paraffin oil and porous oil-carrying composite self-lubricating component, continue mixing for 60-120s, and discharge the rubber compound when the temperature reaches 125-135℃ to obtain a first-stage compound. S4. Cool the first section of the compound to below 50°C and let it stand for 4-12 hours. Then add it to a mixer and add pre-dispersed sulfur masterbatch, TMTD-80GN pre-dispersion accelerator, DPTT-70GE pre-dispersion accelerator, ZDBC-80GE pre-dispersion accelerator, ZDTP-70 pre-dispersion accelerator, ZBEC-70GE pre-dispersion accelerator, CBS-80PE pre-dispersion accelerator and MBTS-75GE pre-dispersion accelerator in sequence at 50-80°C. Mix for 2-4 minutes and discharge the compound when the temperature is not higher than 100°C to obtain the self-lubricating material for the tailgate strut bellows. S5. Place the tailgate strut bellows in a bellows mold with a self-lubricating material, and mold and vulcanize it for 8-12 minutes at 165-175℃ and 8-12MPa. After demolding, cool it to 30-40℃ to obtain the tailgate strut bellows.

9. The preparation method according to claim 8, characterized in that, In step S3, the porous oil-carrying composite self-lubricating component is added in two batches, with the two addition amounts being 55-65% and 35-45% of the total mass of the porous oil-carrying composite self-lubricating component, respectively, and the time interval between the two additions being 30-60 seconds.

10. A tailgate strut corrugated pipe, characterized in that, The tailgate strut bellows is made of the tailgate strut bellows as described in any one of claims 1-7 by compression molding and vulcanization using a self-lubricating material; The porous oil-loaded composite self-lubricating component is dispersed in the rubber matrix of the tailgate strut bellows. The porous oil-loaded composite self-lubricating component includes mesoporous silica loaded with dimethyl silicone oil, thermoplastic acrylic modified silicone resin, and polytetrafluoroethylene micro powder. Standard vulcanized test pieces were prepared by molding and vulcanizing the same batch of unvulcanized rubber compound used to prepare the tailgate strut bellows at 170°C and 10MPa for 10 minutes. The Shore A hardness measured according to ASTM D2240 was 55-65, and the tensile strength measured according to ASTM D412 was not less than 8MPa and the elongation at break was not less than 400%. The Mooney viscosity of the same batch of unvulcanized rubber compound measured at 100°C in ML (1+4) was 20-28MU.

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