High-elasticity fatigue-resistant rubber sealing ring and preparation method thereof

Abstract

This application relates to the field of rubber sealing ring processing technology, and more specifically, to a highly elastic and fatigue-resistant rubber sealing ring and its preparation method. It is prepared from the following raw materials in parts by weight: 100 parts silicone, 30-50 parts silica, 5-10 parts high-vinyl silicone oil, 4-6 parts vinyl-terminated polyborosiloxane, 5-10 parts vinyl-terminated fluorosilicone oil, 2-4 parts phenyltriethoxysilane, 1-2 parts CeO2@vinylsiloxane core-shell particles, 3-5 parts hydroxyl silicone oil, 5-8 parts methyl silicone oil, 1-3 parts hydrogen-containing silicone oil, and 0.8-1 parts platinum catalyst. The rubber sealing ring prepared by the above formulation exhibits excellent aging resistance, elastic recovery ability, and fatigue resistance. It maintains good sealing contact pressure even under long-term compressive stress and micro-vibration environments, effectively suppressing stress relaxation and permanent deformation. Simultaneously, it effectively delays surface hardening, cracking, and powdering, significantly extending the service life of the sealing ring in medical monitors.

Description

Technical Field

[0001] This application relates to the field of rubber sealing ring processing technology, and more specifically, to a highly elastic and fatigue-resistant rubber sealing ring and its preparation method. Background Technology

[0002] Currently, the seals commonly used in medical monitors are mainly made of elastomeric materials, including silicone rubber, fluororubber, and EPDM rubber. These materials are processed into specific shapes of sealing rings, gaskets, or strips through compression molding or injection molding processes, and installed in critical locations such as the seams of the monitor's casing, the bezel of the display screen, around the buttons, cable interfaces, and sensor connections. Among these, silicone rubber has become the preferred material for medical monitor seals due to its excellent biocompatibility, resistance to high and low temperatures (-60℃ to 200℃), and good electrical insulation properties.

[0003] In practical use, silicone rubber meets the basic sealing requirements of medical monitors to a certain extent, but the following problems may occur during long-term continuous use: Medical monitors typically require 24 / 7 continuous operation, placing the seals under constant compressive stress and subjecting them to the micro-vibrations generated during operation. Existing elastomeric seals are prone to molecular chain breakage and recombination under dynamic stress, leading to stress relaxation and permanent deformation, resulting in insufficient fatigue resistance. After 6 months to 1 year of continuous use, the permanent compression deformation rate of the seals often exceeds 30%, losing their original elastic recovery ability, causing a decrease in sealing contact pressure, and significantly increasing the risk of seal failure. Especially when the monitor is frequently moved, transported, or subjected to accidental impacts, fatigue cracks in the seals can propagate rapidly, leading to sudden seal failure.

[0004] To prevent cross-infection, the surface of the equipment needs to be frequently wiped and disinfected with chemical reagents such as chlorine-containing disinfectants, alcohol, and hydrogen peroxide. These disinfectants have a strong oxidizing and swelling effect on the sealing materials. At the same time, the heat generated by the operation of the electronic components inside the monitor keeps the sealing materials in a warm environment of 40°C to 60°C for a long time, which accelerates the thermal aging of the materials. Summary of the Invention

[0005] To address the issues of insufficient fatigue resistance and aging in silicone rubber seals, this application provides a highly elastic, fatigue-resistant rubber seal and its preparation method.

[0006] In a first aspect, this application provides a highly elastic and fatigue-resistant rubber sealing ring, employing the following technical solution: A highly elastic and fatigue-resistant rubber sealing ring is prepared from the following raw materials in parts by weight: 100 parts silicone 30-50 parts of silica 5-10 parts of high vinyl silicone oil Vinyl-terminated polyborosiloxane 4-6 parts 5-10 parts of vinyl-terminated fluorosilicone oil 2-4 parts of phenyltriethoxysilane 8-12 parts of CeO2@vinylsiloxane core-shell particles 3-5 parts of hydroxy silicone oil 5-8 parts methyl silicone oil 1-3 parts of hydrogen-containing silicone oil 0.8-1 part platinum catalyst.

[0007] By adopting the above technical solution, the rubber sealing ring is made with good aging resistance, elastic recovery ability and fatigue resistance. It can maintain good sealing contact pressure under long-term compressive stress and micro-vibration environment, effectively suppressing stress relaxation and permanent deformation, and greatly extending the service life of the sealing ring under the condition of 7×24-hour uninterrupted operation of medical monitor, ensuring the long-term reliable sealing performance of the equipment.

[0008] Among them, vinyl-terminated fluorosilicone oil is blended with silicone to form an interpenetrating network. Utilizing the low surface energy and strong CF bond characteristics of fluorine atoms, this significantly improves the sealing ring's resistance to swelling and corrosion from chlorine-containing disinfectants, alcohol, and other chemical reagents, thus slowing down the aging process of the sealing ring. Vinyl-terminated polyborosiloxane introduces dynamically reversible boron-oxygen bonds, which can effectively dissipate energy through bond breaking and recombination under micro-vibration and dynamic compressive stress, inhibiting crack propagation and thus endowing the material with good fatigue resistance and resistance to permanent deformation. CeO2@vinylsiloxane core-shell particles serve as functional nanofillers. The material's core, cerium dioxide, plays an excellent role in capturing free radicals, blocking the chain reaction of thermo-oxidative aging. The outer shell, vinylsiloxane, ensures its chemical bonding with the matrix, preventing agglomeration and enhancing interfacial adhesion. Combined with high vinyl silicone oil to adjust crosslinking density, phenyltriethoxysilane to improve heat resistance, and silica for reinforcement, the synergistic effect of these components allows the final sealing ring to maintain extremely low compression set and high elastic recovery force even under 40℃-60℃ warm environments and continuous dynamic loads, extending its service life and ensuring the long-term sealing reliability of medical devices.

[0009] Preferably, the CeO2@vinylsiloxane core-shell particles are prepared by the following method: 1) Disperse CeO2 ultrasonically in anhydrous ethanol to prepare a dispersion of 0.5-2.0 wt%. Add deionized water dropwise under stirring, controlling the volume ratio of ethanol to water to be (8-10):1. Adjust the pH to 4.0-5.0 with acetic acid. Stir at room temperature for 30-60 min to obtain surface hydroxylated CeO2. 2) Under nitrogen protection, vinyltrimethoxysilane is slowly added dropwise to the above hydroxylated dispersion at a rate of 1-3 drops / second, with a mass ratio of vinyltrimethoxysilane to CeO2 of 0.2-0.5:1. After the addition is complete, the mixture is stirred continuously at room temperature for 3-6 hours. 3) Heat the reaction system to 50-70℃, add ammonia to adjust the pH to 8.0-9.0, react for 4-8 hours, filter, take the filter residue, rinse and dry to obtain CeO2@vinylsiloxane core-shell particles.

[0010] By adopting the above technical solution, active hydroxyl groups are first introduced on the CeO2 surface through ultrasonic dispersion and acid-catalyzed hydrolysis to provide reaction sites for the subsequent silane coupling reaction. Then, vinyltrimethoxysilane is used for a room temperature grafting reaction under nitrogen protection. By controlling the dropping rate, the silane molecules are uniformly coated on the CeO2 surface to form a stable vinyl functionalized intermediate layer. Finally, a condensation reaction is carried out under weakly alkaline conditions to further crosslink and solidify the silane molecules, forming a dense and complete vinylsiloxane shell structure. This core-shell particle organically combines the antioxidant and heat-resistant properties of inorganic CeO2 with the interfacial compatibility and reactivity of organovinylsiloxane through chemical bonding. On the one hand, it utilizes the rare earth element variable valence characteristics of CeO2 to effectively capture free radicals and delay the thermo-oxidative aging process of the rubber matrix. On the other hand, it participates in the vulcanization and cross-linking reaction of silicone rubber through surface vinyl groups, realizing chemical bonding between the particles and the matrix. This significantly improves the interfacial bonding strength between the filler and the matrix, thereby ensuring the high elasticity of the material while further enhancing the fatigue resistance and chemical corrosion resistance of the sealing ring. This effectively solves the problem of aging failure of medical monitor sealing components under long-term dynamic stress and disinfection environment.

[0011] Preferably, the silicone is methyl vinyl silicone rubber, wherein the vinyl content of the methyl vinyl silicone rubber is 0.18-0.25 mol%, and the weight-average molecular weight is 600,000-800,000.

[0012] By adopting the above technical solutions and optimizing the type and parameters of silicone, the silicone rubber is ensured to have suitable cross-linking reactivity and vulcanization density. This ensures the material's high elastic recovery ability while avoiding increased brittleness due to excessive cross-linking. At the same time, the appropriate molecular weight gives the molecular chains sufficient chain entanglement density and physical cross-linking points, improving the material's mechanical strength and fatigue resistance, enabling it to maintain good elastic stability under long-term compressive stress.

[0013] Preferably, the high-vinyl silicone oil has a molecular weight of 10,000-20,000 and a vinyl content of 5-10 mol.

[0014] By adopting the above technical solution, the high vinyl content provides abundant reaction sites, which can form a multi-point crosslinking network with the matrix silicone rubber and crosslinking agent, effectively improving the crosslinking density and reducing aging; the appropriate molecular weight has good fluidity and dispersibility, and can be uniformly penetrated into the rubber matrix. Under dynamic stress, it can effectively absorb and dissipate energy through the flexible movement of molecular chains, thereby improving the fatigue resistance and elastic recovery ability of the sealing ring, and effectively alleviating the problem of fatigue crack propagation in medical monitor sealing components under long-term compression.

[0015] Preferably, the vinyl-terminated polyborosiloxane has the following structural formula: Vi-(Me2SiO) a -(BO-SiMe2-O)ᵦ-(SiMe2O)c-Me2Si-Vi Wherein, Vi is vinyl, Me is methyl, a+c is 10-30, ᵦ is 3-8, boron content is 2-5wt%, and viscosity at 25℃ is 100-500mPa.s.

[0016] By adopting the above technical solutions, the structure and parameters of vinyl-terminated polyborosiloxane are optimized. The introduction of BO-Si bonds in the main chain endows the molecular chain with unique flexibility and thermal stability. The electron-deficient characteristics of boron enable it to capture free radicals and effectively inhibit thermo-oxidative aging. The vinyl-terminated structure enables it to participate in vulcanization crosslinking, and the introduction of boron-containing structures into the crosslinking network improves the thermo-oxidative aging resistance and chemical corrosion resistance of silicone rubber. The appropriate chain segment length and viscosity ensure that it has good dispersibility and interfacial compatibility in the matrix, thereby effectively delaying the hardening, cracking and powdering of the seals under the 40-60℃ warm environment and disinfectant corrosion conditions generated by the long-term operation of medical monitors.

[0017] Preferably, the vinyl-terminated fluorosilicone oil is α,ω-divinyl polymethyltrifluoropropylsiloxane, with a fluorine content of 15-25 wt%, a vinyl content of 0.8-1.2 mmol / g, and a viscosity of 500-2000 mPa·s at 25°C.

[0018] By adopting the above technical solution and optimizing the type and parameters of the vinyl-terminated fluorosilicone oil, fluorine endows silicone rubber with excellent chemical corrosion resistance and oxidation resistance, effectively resisting the erosion of chemical reagents such as chlorine-containing disinfectants, alcohol, and hydrogen peroxide; the appropriate vinyl content enables it to participate in the cross-linking reaction, stably introducing fluorosilicone segments into the network structure; the specific viscosity range ensures that it has good processing fluidity during the mixing process, and can uniformly coat the filler and rubber molecule surface to form a dense fluorinated protective layer, thereby improving the swelling resistance and surface stability of the sealing ring in frequent disinfection environments, and effectively preventing sealing failure caused by chemical aging.

[0019] Preferably, the methyl silicone oil is dimethyl silicone oil with a viscosity of 100-1000 mPa·s at 25°C.

[0020] By adopting the above technical solution, dimethyl silicone oil can migrate to the material surface to form a hydrophobic protective layer, reducing the penetration of disinfectant molecules. At the same time, through lubrication, it reduces the frictional loss of the seal during dynamic compression, thereby helping to improve the fatigue resistance and long-term sealing reliability of the sealing ring.

[0021] Preferably, the hydroxyl content of the hydroxyl silicone oil is 6-10 wt%, and the molecular weight is 5000-10000.

[0022] By adopting the above technical solution, the high hydroxyl content enables it to form hydrogen bonds with the silanol groups on the surface of silica, effectively inhibiting the secondary agglomeration of silica and improving the dispersion uniformity of silica in the rubber matrix; the appropriate molecular weight ensures that it has sufficient chain length to play a structural control role, while maintaining good fluidity, and can effectively coat silica during the mixing process, reducing the Mooney viscosity of the rubber compound.

[0023] Secondly, this application provides a method for preparing a highly elastic fatigue-resistant rubber sealing ring, using the following technical solution: A method for preparing a highly elastic fatigue-resistant rubber sealing ring includes the following steps: S1. Add silica gel, fumed silica, and hydroxyl silicone oil to a mixer and mix at 120-140℃ for 20-40 minutes to obtain the base compound. S2. Cool the base rubber compound to below 60°C, add high vinyl silicone oil, vinyl-terminated polyborosiloxane, vinyl-terminated fluorosilicone oil, phenyltriethoxysilane, CeO2@vinylsiloxane core-shell particles, and methyl silicone oil, and mix at 80-100°C for 15-25 minutes to obtain the mixed rubber compound. S3. Cool the mixed rubber compound to below 40°C, add hydrogen-containing silicone oil and platinum catalyst, stir rapidly under vacuum for 5-10 minutes, vulcanize, and obtain a highly elastic and fatigue-resistant rubber sealing ring.

[0024] By adopting the above technical solution, step S1 involves high-temperature mixing of silicone, silica, and hydroxyl silicone oil, which fully disperses the silica and causes a structural reaction with the hydroxyl silicone oil to form a stable base compound. Step S2 involves adding functional modifiers such as high-vinyl silicone oil and vinyl-terminated polyborosiloxane to avoid premature crosslinking or volatilization loss caused by high temperature, ensuring uniform dispersion of each component. Step S3 involves adding hydrogen-containing silicone oil and platinum catalyst to prevent premature catalytic reaction of the platinum catalyst at high temperature, ensuring that the compound has a suitable processing safety period. Finally, vulcanization forms a dense and uniform crosslinked network structure, thereby ensuring that the sealing ring has excellent comprehensive performance and a high yield.

[0025] Preferably, the vulcanization process adopts a two-stage vulcanization process: the first stage vulcanization temperature is 120-140℃, the pressure is 5-10MPa, and the time is 5-15min; the second stage vulcanization temperature is 160-180℃, and the time is 10-30min.

[0026] By adopting the above technical solution, the first stage of vulcanization rapidly establishes the basic framework of the cross-linked network under medium temperature and high pressure conditions, enabling the sealing ring to take shape and obtain initial mechanical strength. The high pressure environment effectively prevents the generation of bubbles and ensures the compactness of the product. The second stage of vulcanization carries out the post-vulcanization reaction at a higher temperature, promoting the full progress of the residual cross-linking reaction, making the cross-linked network more complete and uniform. At the same time, through heat aging stabilization treatment, the internal stress is relaxed, thereby improving the dimensional stability, mechanical property uniformity and long-term aging resistance of the sealing ring.

[0027] In summary, this application has the following beneficial effects: The sealing ring prepared in this application exhibits excellent fatigue resistance and resistance to permanent deformation. By introducing dynamic reversible boron-oxygen bonds into vinyl-terminated polyborosiloxane, it effectively dissipates micro-vibration energy and inhibits crack propagation, ensuring high elastic recovery and extremely low compression set under long-term compression and 7×24-hour dynamic load. The interpenetrating network formed by the vinyl-terminated fluorosilicone oil significantly improves resistance to swelling from chlorine-containing disinfectants and alcohol. CeO2@core-shell particles utilize cerium dioxide to capture free radicals, blocking the thermo-oxidative aging chain reaction, and, in conjunction with phenyltriethoxysilane, improve heat resistance. Furthermore, the vinyl groups on the surface of the functional core-shell particles participate in sulfurization crosslinking, achieving chemical bonding between the filler and the matrix, preventing agglomeration and enhancing interfacial adhesion. The synergistic effect of the components enables the sealing ring to maintain reliable sealing contact pressure even under high temperature and continuous dynamic stress environments of 40℃-60℃, effectively solving the problem of aging failure of medical monitor seals under harsh conditions and significantly extending the service life of the equipment. Detailed Implementation Preparation Example

[0028] Preparation Example 1 A CeO2@vinylsiloxane core-shell particle is prepared by the following method: 1) Disperse 20g of CeO2 in anhydrous ethanol by ultrasonication to prepare a 0.5wt% dispersion. Add deionized water dropwise under stirring to control the volume ratio of ethanol to water at 8:1. Adjust the pH to 4.0 with acetic acid and stir at room temperature for 30 min to obtain surface hydroxylated CeO2. 2) Under nitrogen protection, vinyltrimethoxysilane was slowly added dropwise to the above hydroxylated dispersion at a rate of 1 drop / second, with a mass ratio of vinyltrimethoxysilane to CeO2 of 0.2:1. After the addition was completed, the mixture was stirred continuously at room temperature for 3-6 hours. 3) Heat the reaction system to 50°C, add ammonia (10% by mass) and CeO21%, adjust the pH to 8.0, react for 4 hours, filter, take the filter residue, rinse and dry to obtain CeO2@vinylsiloxane core-shell particles.

[0029] The difference between Preparation Examples 2-3 and Preparation Example 1 lies in the types, amounts, and parameters of raw materials used to prepare the highly elastic and fatigue-resistant rubber seals. Specific differences are shown in Table 1. Table 1. Types, amounts, and parameters of raw materials used in the preparation of CeO2@vinylsiloxane core-shell particles. Example

[0030] The hydrogen-containing silicone oil has a hydrogen content of 1.2 wt%, a viscosity range of 10 mPa·s, and a molecular weight of 3000.

[0031] The platinum catalyst is a Karstedt catalyst with a platinum content of 3000 ppm.

[0032] Example 1

[0033] A highly elastic and fatigue-resistant rubber sealing ring is prepared by the following method: S1. Add 100g of silicone, 30g of fumed silica and 3g of hydroxyl silicone oil to a mixer and mix at 120℃ for 20 minutes to obtain the base compound. The silicone is methyl vinyl silicone rubber, with a vinyl content of 0.18 mol% and a weight-average molecular weight of 600,000. The hydroxyl content of the hydroxyl silicone oil is 6 wt%, and the molecular weight is 5000. S2. Cool the base compound to below 60°C, add 5g of high vinyl silicone oil, 3g of vinyl-terminated polyborosiloxane, 5g of vinyl-terminated fluorosilicone oil, 2g of phenyltriethoxysilane, 8g of CeO2@vinylsiloxane core-shell particles from Preparation Example 1, and 5g of methyl silicone oil, and mix at 80°C for 15 minutes to obtain a mixed compound. The high-vinyl silicone oil has a molecular weight of 10,000 and a vinyl content of 5 mol%. Vinyl-terminated polyborosiloxanes have the following structural formula: Vi-(Me2SiO) a -(BO-SiMe2-O)ᵦ-(SiMe2O)c-Me2Si-Vi Wherein, Vi is vinyl, Me is methyl, a is 5, c is 5, a+c is 10, ᵦ is 3, boron content is 2wt%, and viscosity at 25℃ is 100mPa.s; The vinyl-terminated fluorosilicone oil is α,ω-divinyl polymethyltrifluoropropylsiloxane, with a fluorine content of 15wt%, a vinyl content of 0.8mmol / g, and a viscosity of 500mPa.s at 25℃. Methyl silicone oil is dimethyl silicone oil with a viscosity of 100 mPa·s at 25°C. The hydroxyl content of the hydroxyl silicone oil is 6 wt%, and the molecular weight is 5000. S3. Cool the mixed rubber compound to below 40°C, add 1g of hydrogen-containing silicone oil and 0.8g of platinum catalyst, stir rapidly under vacuum for 5 minutes, vulcanize, and obtain a highly elastic and fatigue-resistant rubber sealing ring. The vulcanization process adopts a two-stage vulcanization process: the first stage vulcanization temperature is 120℃, the pressure is 5MPa, and the time is 5min; the second stage vulcanization temperature is 160℃ and the time is 10min.

[0034] The difference between Examples 2-3 and Example 1 lies in the types, amounts, and parameters of raw materials used to prepare the highly elastic, fatigue-resistant rubber sealing rings. Specific differences are shown in Table 2. Table 2. Raw material types, dosages, and parameters for preparing highly elastic and fatigue-resistant rubber seals.

[0035]

[0036] Example 4

[0037] A highly elastic and fatigue-resistant rubber sealing ring, the difference between this embodiment and Embodiment 1 is that the fluorine content of α,ω-divinyl polymethyltrifluoropropylsiloxane is 10wt%.

[0038] Example 5

[0039] A highly elastic and fatigue-resistant rubber sealing ring, the difference between this embodiment and Embodiment 1 is that in the vinyl-terminated polyborosiloxane, a is 10, c is 25, and a+c is 40.

[0040] Example 6

[0041] A highly elastic and fatigue-resistant rubber sealing ring, the difference between this embodiment and Embodiment 1 is that in the vinyl-terminated polyborosiloxane, a is 5, c is 3, and a+c is 8.

[0042] Example 7

[0043] A highly elastic and fatigue-resistant rubber sealing ring, the difference between this embodiment and Embodiment 1 is that the high vinyl silicone oil has a molecular weight of 10,000 and a vinyl content of 3 mol. Comparative Example

[0044] Comparative Example 1 A rubber sealing ring, the difference between this comparative example and Example 1 is that CeO2@vinylsiloxane core-shell particles are replaced with CeO2.

[0045] Comparative Example 2 A rubber sealing ring, which differs from Example 1 in that it does not contain high-vinyl silicone oil.

[0046] Comparative Example 3 A rubber sealing ring, the difference between this comparative example and Example 1 is that vinyl-terminated polydimethylsiloxane is used instead of vinyl-terminated polyborosiloxane.

[0047] The vinyl-terminated polydimethylsiloxane has a viscosity of 100 mPa·s at 25°C and a vinyl content of 0.18 mol.

[0048] Comparative Example 4 A rubber sealing ring, the difference between this comparative example and Example 1 is that hydroxyl-terminated fluorosilicone oil is used instead of vinyl-terminated fluorosilicone oil.

[0049] Hydroxyl-terminated fluorosilicone oil with a fluorine content of 15wt%, a hydroxyl group content of 0.8mmol / g, and a viscosity of 500mPa.s at 25℃.

[0050] Comparative Example 5 A rubber sealing ring, the difference between this comparative example and Example 1 is that vinyltriethoxysilane is used instead of phenyltriethoxysilane. Detection methods / test methods

[0051] Compression set: Refer to ASTM D395, Method B, compress at 30℃ and 70℃ for 22 hours respectively; Elastic recovery rate: Refer to ASTM D2632; Tensile strength and elongation at break: Refer to ASTM D412; Solvent resistance test: The rubber sealing ring was placed in 84 disinfectant solution for 72 hours, removed, dried, and then the tensile strength was tested. The tensile strength retention rate was calculated. The experimental data are shown in Table 3. Table 3 Experimental data of Examples 1-7 and Comparative Examples 1-5

[0052] The experimental data above show that, through the synergistic combination of CeO2@vinylsiloxane core-shell particles, high-vinyl silicone oil, vinyl-terminated polyborosiloxane, vinyl-terminated fluorosilane oil, and phenyltriethoxysilane, a rubber sealing ring with high elasticity, fatigue resistance, aging resistance, and chemical corrosion resistance can be prepared, meeting the stringent requirements of 24 / 7 uninterrupted operation of medical monitors.

[0053] Comparing the experimental data of Example 1 and Comparative Examples 1-5, it can be seen that adding the CeO2@vinylsiloxane core-shell particles and vinyl-terminated polyborosiloxane prepared in this application can improve the fatigue resistance of the sealing ring; adding an appropriate amount of high-vinyl silicone oil can enhance the mechanical strength and resistance to permanent deformation of the sealing ring; adding vinyl fluorosilicone oil can significantly improve the corrosion resistance of the sealing ring; and adding phenyltriethoxysilane can further improve the stability of the sealing ring performance. It is evident that through the synergistic effect of each component under the specific ratios of this application, Example 1 comprehensively outperforms the comparative examples lacking any single component in terms of fatigue resistance, elastic recovery, chemical corrosion resistance, and high-temperature stability, thus solving the problem of aging failure of medical monitor sealing components under long-term dynamic stress and sterilization environments.

[0054] Comparing the experimental data from Examples 1 and 4-7, it can be seen that optimizing the parameters of the vinyl-terminated fluorosilicone oil, the vinyl-terminated polyborosiloxane, and the high-vinyl silicone oil further improves the fatigue resistance of the sealing ring, ensuring that the sealing ring still has high elastic recovery capability under long-term dynamic load. The three factors work together to enable the rubber sealing ring to simultaneously meet the multiple requirements of chemical disinfection resistance, dynamic fatigue resistance, and long-term dimensional stability under the harsh conditions of 7×24-hour uninterrupted operation of medical monitors.

[0055] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A highly elastic, fatigue-resistant rubber sealing ring, characterized in that, It is prepared from the following raw materials in parts by weight: 100 parts silicone 30-50 parts of silica 5-10 parts of high vinyl silicone oil Vinyl-terminated polyborosiloxane 4-6 parts 5-10 parts of vinyl-terminated fluorosilicone oil 2-4 parts of phenyltriethoxysilane 8-12 parts of CeO2@vinylsiloxane core-shell particles 3-5 parts of hydroxy silicone oil 5-8 parts methyl silicone oil 1-3 parts of hydrogen-containing silicone oil 0.8-1 part platinum catalyst.

2. The highly elastic, fatigue-resistant rubber sealing ring according to claim 1, characterized in that, The CeO2@vinylsiloxane core-shell particles were prepared by the following method: 1) Disperse CeO2 ultrasonically in anhydrous ethanol to prepare a dispersion of 0.5-2.0 wt%. Add deionized water dropwise under stirring, controlling the volume ratio of ethanol to water to be (8-10):

1. Adjust the pH to 4.0-5.0 with acetic acid. Stir at room temperature for 30-60 min to obtain surface hydroxylated CeO2. 2) Under nitrogen protection, vinyltrimethoxysilane is slowly added dropwise to the above hydroxylated dispersion at a rate of 1-3 drops / second, with a mass ratio of vinyltrimethoxysilane to CeO2 of 0.2-0.5:

1. After the addition is complete, the mixture is stirred continuously at room temperature for 3-6 hours. 3) Heat the reaction system to 50-70℃, add ammonia water, adjust the pH to 8.0-9.0, react for 4-8 hours, filter, take the filter residue, rinse and dry to obtain CeO2@vinylsiloxane core-shell particles.

3. The highly elastic, fatigue-resistant rubber sealing ring according to claim 1, characterized in that: The silicone rubber is methyl vinyl silicone rubber, and the vinyl content of the methyl vinyl silicone rubber is 0.18-0.25 mol%, and the weight average molecular weight is 600,000-800,000.

4. The highly elastic, fatigue-resistant rubber sealing ring according to claim 1, characterized in that: The high-vinyl silicone oil has a molecular weight of 10,000-20,000 and a vinyl content of 5-10 mol.

5. The highly elastic, fatigue-resistant rubber sealing ring according to claim 1, characterized in that: The vinyl-terminated polyborosiloxane has the following structural formula: Vi-(Me2SiO) a -(BO-SiMe2-O)ᵦ-(SiMe2O) c -Me2Si-Vi Wherein, Vi is vinyl, Me is methyl, a+c is 10-30, ᵦ is 3-8, boron content is 2-5wt%, and viscosity at 25℃ is 100-500mPa.s.

6. The highly elastic, fatigue-resistant rubber sealing ring according to claim 1, characterized in that: The vinyl-terminated fluorosilicone oil is α,ω-divinyl polymethyltrifluoropropylsiloxane, with a fluorine content of 15-25wt%, a vinyl content of 0.8-1.2mmol / g, and a viscosity of 500-2000mPa.s at 25℃.

7. The highly elastic, fatigue-resistant rubber sealing ring according to claim 1, characterized in that: The methyl silicone oil is dimethyl silicone oil with a viscosity of 100-1000 mPa·s at 25°C.

8. The highly elastic, fatigue-resistant rubber sealing ring according to claim 1, characterized in that: The hydroxyl content of the hydroxyl silicone oil is 6-10 wt%, and the molecular weight is 5000-10000.

9. A method for preparing a high-elasticity fatigue-resistant rubber sealing ring as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Add silica gel, fumed silica, and hydroxyl silicone oil to a mixer and mix at 120-140℃ for 20-40 minutes to obtain the base compound. S2. Cool the base rubber compound to below 60°C, add high vinyl silicone oil, vinyl-terminated polyborosiloxane, vinyl-terminated fluorosilicone oil, phenyltriethoxysilane, CeO2@vinylsiloxane core-shell particles, and methyl silicone oil, and mix at 80-100°C for 15-25 minutes to obtain the mixed rubber compound. S3. Cool the mixed rubber compound to below 40°C, add hydrogen-containing silicone oil and platinum catalyst, stir rapidly under vacuum for 5-10 minutes, vulcanize, and obtain a highly elastic and fatigue-resistant rubber sealing ring.

10. The method for preparing a highly elastic fatigue-resistant rubber sealing ring according to claim 9, characterized in that, The vulcanization process employs a two-stage vulcanization process: the first stage vulcanization temperature is 120-140℃, the pressure is 5-10MPa, and the time is 5-15min; the second stage vulcanization temperature is 160-180℃, and the time is 10-30min.

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