High oil resistance and high sealing composite material, preparation method and application thereof

Abstract

This application discloses a composite material with high oil resistance and high sealing performance, its preparation method, and its application, belonging to the field of polymer materials technology. By weight, it comprises 60-90 parts of fluorosilicone rubber raw rubber, 10-30 parts of fluororubber, 5-10 parts of nitrile rubber, 15-30 parts of reinforcing filler, 5-15 parts of interface reinforcing filler, 2-6 parts of microporous foaming agent, 2-6 parts of vulcanizing agent, 1-3 parts of antioxidant, and 0.5-1.5 parts of internal release agent; wherein the interface reinforcing filler is a modified compound of molybdenum disulfide and graphene oxide. Through the synergistic effect of the ternary system of the rubber matrix and the specific interface reinforcing filler, combined with microporous foaming technology, the composite material maintains excellent mechanical strength while possessing superior oil expansion resistance and high sealing reliability, making it suitable for manufacturing sealing elements under harsh operating conditions such as electric slide gate valves.

Description

Technical Field

[0001] This application relates to a composite material with high oil resistance and high sealing performance, its preparation method and application, belonging to the field of polymer materials technology. Background Technology

[0002] Electric slide gate valves are valves that control the size of fluid passages by sliding a slide gate. They are widely used in metallurgy, power, chemical, mining, and environmental dust control systems. In petrochemical, coking, and oil transportation scenarios, the seals of slide gate valves are in long-term contact with gasoline, diesel, lubricating oil, aromatic solvents, and high-temperature oil vapors, and are subjected to frequent opening and closing shearing, pressure fluctuations, and temperature changes. Therefore, extremely high comprehensive performance requirements are placed on the sealing materials of slide gate valves: excellent resistance to oil swelling, extremely low compression set, low coefficient of friction, and good thermal and oxidative aging stability.

[0003] Currently, the commonly used sealing materials for electric slide gate valves mainly include fluororubber, nitrile rubber, polytetrafluoroethylene (PTFE), and ordinary fluorosilicone rubber. However, each of these individual materials has significant drawbacks: fluororubber has poor elasticity and a high coefficient of friction; nitrile rubber lacks sufficient resistance to high temperatures and polar oils; PTFE has extremely poor elasticity, poor adhesion to metals, and is prone to leakage; and ordinary fluorosilicone rubber has low mechanical strength and poor tear resistance. None of these materials can meet the requirements for long-term maintenance-free operation of slide gate valves.

[0004] To balance oil resistance and sealing elasticity, existing technologies have attempted to simply blend fluororubber with nitrile rubber or acrylate rubber, or add conventional reinforcing fillers (such as carbon black, silica, etc.). However, problems still exist, such as poor interfacial compatibility, rapid penetration of oil media along the filler-rubber interface, and uneven dispersion of fillers leading to an increased coefficient of friction.

[0005] Therefore, there is an urgent market demand and significant engineering value in developing a high-sealing composite material for electric slide gate valves that has excellent oil resistance, low coefficient of friction, and microporous elastic compensation capability. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a composite material with high oil resistance and excellent sealing performance. Through the synergistic effect of a ternary system of rubber matrix and specific interface-reinforcing fillers, combined with microporous foaming technology, the composite material maintains excellent mechanical strength while exhibiting superior oil expansion resistance and high sealing reliability.

[0007] According to one aspect of this application, a composite material with high oil resistance and high sealing performance is provided, comprising, by weight, 60-90 parts of fluorosilicone rubber raw rubber, 10-30 parts of fluororubber, 5-10 parts of nitrile rubber, 15-30 parts of reinforcing filler, 5-15 parts of interface reinforcing filler, 2-6 parts of microporous foaming agent, 2-6 parts of vulcanizing agent, 1-3 parts of antioxidant, and 0.5-1.5 parts of internal release agent; The interface-enhancing filler is a modified compound of molybdenum disulfide and graphene oxide.

[0008] Fluorosilicone rubber provides excellent resistance to high and low temperatures, oil, aging, and low surface energy. Fluororubber enhances resistance to mineral oil, organic solvents, and media corrosion. Nitrile rubber improves mechanical strength, wear resistance, and processability. The combination of these three materials works synergistically to compensate for the shortcomings of individual rubbers, achieving basic properties of high oil resistance, high elasticity, and high sealing performance.

[0009] The modified molybdenum disulfide and graphene oxide compound, as an interface reinforcing filler, can improve the bonding force between the filler and the rubber interface, reduce interface defects, and at the same time construct a dense barrier network. Furthermore, its two-dimensional sheet structure can physically block the diffusion of oil molecules.

[0010] Adding a microporous foaming agent can form closed micropores during vulcanization, which is beneficial for absorbing contact stress, improving sealing performance, and reducing the actual contact area of ​​the friction surface, thus lowering the coefficient of dynamic friction.

[0011] The synergistic effect of the components gives the composite material high oil resistance, high resilience, low friction, and long-term sealing stability.

[0012] Optionally, the mass ratio of the fluororubber to the nitrile rubber is (2-5):1.

[0013] This mass ratio ensures that the high oil resistance of fluororubber plays a dominant role while reasonably incorporating the strong mechanical and processing properties of nitrile rubber. It avoids the reduction in oil and temperature resistance caused by an excessively high nitrile rubber content, and also prevents the product from becoming too hard and having poor sealing and resilience due to an excessive fluororubber content. Simultaneously, this mass ratio results in optimal compatibility at the ternary rubber phase interface, reducing problems such as phase separation and internal micropore defects in the blend system, further stabilizing the oil resistance of the composite material and making it better suited for the long-term sealing conditions of electric slide gate valves.

[0014] Optionally, the molar content of vinyl groups in the fluorosilicone rubber raw material is 0.2-2%.

[0015] Limiting the vinyl content ensures a moderate crosslinking density, thereby controlling the degree of crosslinking reaction. This guarantees the product's mechanical strength and oil resistance stability while retaining excellent elasticity and sealing resilience. Too low a content leads to insufficient crosslinking and easy deformation, while too high a content results in overly dense crosslinking, brittleness, and reduced sealing adhesion.

[0016] Optionally, the fluororubber is a vinylidene fluoride rubber with a Mooney viscosity of 30-60 M.

[0017] Vinylidene fluoride fluororubber has excellent resistance to oil and acid / alkali media. Its specific Mooney viscosity range can better adapt to internal mixing and open milling processes, so that the flowability and processability of the composite material are balanced. It can be evenly dispersed during mixing, avoiding the problem of difficult mixing due to excessive viscosity and poor dimensional stability of molding due to excessive viscosity.

[0018] Optionally, the vinylidene fluoride rubber is fluororubber 26 or fluororubber 246.

[0019] Optionally, the acrylonitrile content in the nitrile rubber is 30-50 wt%.

[0020] The higher the acrylonitrile content, the stronger the oil resistance, but too high acrylonitrile content can lead to brittleness at low temperatures, so its content is limited to 30-50 wt%.

[0021] Optionally, the preparation of the interface-reinforcing filler includes the following steps: Molybdenum disulfide was treated with oxygen plasma, then mixed with graphene oxide and silane coupling agent, and ball-milled for 1-4 hours with anhydrous ethanol as the dispersion medium at a speed of 200-400 rpm. After the process, the anhydrous ethanol was removed to obtain the final product. The mass ratio of molybdenum disulfide to graphene oxide is (1-1.2):1, and the amount of silane coupling agent added is 1-3% of the total mass of molybdenum disulfide and graphene oxide.

[0022] Molybdenum disulfide, after oxygen plasma treatment, introduces hydrophilic oxygen-containing functional groups on its surface, improving its wettability with graphene oxide and rubber matrices, thus solving the problem of inorganic filler agglomeration. Dispersed in anhydrous ethanol, the molybdenum disulfide and graphene oxide are uniformly dispersed and exfoliated through ball milling. Simultaneously, a silane coupling agent enables chemical bonding between the inorganic filler and the organic rubber, significantly improving interfacial bonding strength. The modified filler can form a continuous barrier network within the rubber, further blocking oil penetration channels and simultaneously improving the composite material's wear resistance and compression set resistance.

[0023] Molybdenum disulfide can improve the wear resistance and lubricity of composite materials, while graphene oxide can construct a physical barrier layer, strengthen interfacial bonding, and improve oil resistance and mechanical properties. However, if there is too much graphene oxide, it is easy for the sheets to stack up, and if there is too much molybdenum disulfide, it is easy for it to agglomerate. At this mass ratio, the two can achieve complementary functions, ensuring wear resistance and wear resistance, enhancing oil resistance and sealing, and preventing agglomeration.

[0024] Optionally, the silane coupling agent is at least one of γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

[0025] Optionally, the graphene oxide has fewer than 10 layers and the molar content of oxygen-containing functional groups is 30-50%.

[0026] Few-layer graphene oxide has a large specific surface area and regular layers, which can form a two-dimensional sheet-like physical barrier layer inside the rubber. The labyrinth effect can extend the oil penetration path and significantly improve oil resistance and sealing performance.

[0027] Within this range of oxygen-containing functional groups, sufficient reaction sites with silane coupling agents and rubber molecules can be ensured to enhance interfacial adhesion. At the same time, excessive functional groups can be avoided to prevent lamellar aggregation and increased moisture absorption, thus preventing performance degradation under high-temperature oil immersion and balancing its interfacial bonding with the rubber matrix and its resistance to damp heat and oil.

[0028] Optionally, the oxygen flow rate of the oxygen plasma treatment is 50-100 mL / min, the power is 50-150 W, and the treatment time is 5-15 min.

[0029] Optionally, the microporous foaming agent is sodium bicarbonate, azodicarbonamide, and zinc oxide in a mass ratio of 1:(1-1.5):(1-2).

[0030] The multi-component foaming agent, composed of sodium bicarbonate, azodicarbonamide, and zinc oxide, enables segmented and gentle foaming, allowing for controllable foaming rate and gas generation. This results in a uniform, fine, closed-cell microporous structure free of macropores and interconnected pores. The uniform closed-cell structure reduces the hardness of the composite material, enhances its elastic resilience, and cushions deformation under pressure. It also conforms to the valve sealing surface gap, significantly improving sealing performance under low-pressure and low-pressure-difference conditions, while simultaneously reducing material weight and minimizing vibration and noise.

[0031] In addition, zinc oxide has a dual function as a foaming activator and a vulcanization aid, which synergistically regulates the simultaneous occurrence of foaming and vulcanization reactions, avoiding problems such as product collapse and uneven cell size caused by premature or delayed foaming.

[0032] Optionally, the reinforcing filler is fumed silica.

[0033] Optionally, the vulcanizing agent is at least one of dicumyl peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxide, benzoyl peroxide, and bis(2,4-dichlorobenzoyl) peroxide.

[0034] Optionally, the antioxidant is at least one of antioxidant RD, antioxidant 4010NA, antioxidant 4020, antioxidant 1010, and antioxidant 1076.

[0035] Optionally, the internal release agent is zinc stearate or stearic acid.

[0036] According to a second aspect of this application, this application provides a method for preparing the high oil resistance and high sealing performance composite material as described in any of the above claims, comprising the following steps: (1) Fluorosilicone rubber raw rubber, fluororubber and nitrile rubber are mechanically blended and plasticized in an internal mixer to obtain a rubber matrix; (2) Reinforcing filler and interface reinforcing filler are added to the matrix in sequence, and the first compound is obtained after mixing. (3) Transfer the first compound to a two-roll mill, add microporous foaming agent, vulcanizing agent, antioxidant and internal release agent, and mix to obtain the second compound; (4) The second compound is vulcanized to obtain the final product.

[0037] First, the ternary rubber matrix is ​​plasticized and blended through internal mixing to achieve full entanglement of the three rubber molecular chains, improve matrix compatibility, and avoid phase separation caused by the subsequent addition of fillers. Reinforcing fillers and interface-enhancing fillers are added in stages to ensure uniform dispersion of nanofillers, prevent agglomeration, and maximize the reinforcing and interface-enhancing effects. Foaming agents and vulcanizing agents are added in the later open mixing stage. This avoids the problems of premature decomposition of foaming agents and premature failure of vulcanizing agents caused by high-temperature, long-term internal mixing, controls the reaction sequence of foaming and vulcanization, and ensures the synchronous formation of the cell structure and cross-linking network.

[0038] Optionally, the vulcanization in step (4) is as follows: pre-vulcanization at 150-170℃ and 5-10 MPa for 5-15 min; then first-stage vulcanization at 170-190℃ and 10-20 MPa for 15-30 min; and finally second-stage vulcanization at 180-200℃ and 10-20 MPa for 2-5 h.

[0039] The low-temperature, low-pressure pre-curing stage first shapes the composite material and locks in the microporous cell structure to prevent cell collapse and merging under subsequent high-temperature and high-pressure conditions, ensuring the complete preservation of the fine closed-cell structure. A subsequent curing stage completes the main cross-linking and molding of the composite material, constructing a stable rubber cross-linking network and endowing the material with fundamental mechanical and sealing properties.

[0040] Finally, the high-temperature and long-duration second-stage vulcanization process can completely eliminate residual small molecules of vulcanization, release internal stress, further increase crosslinking density, reduce compression set, and improve oil resistance, temperature resistance, and aging resistance stability, making the composite material suitable for the harsh working conditions of electric slide gate valves, such as long-term high-temperature oil immersion and frequent opening and closing.

[0041] According to a third aspect of this application, this application provides the application of the high oil resistance and high sealing performance composite material described in any one of the above claims, or the composite material prepared by the preparation method of the high oil resistance and high sealing performance composite material described in any one of the above claims, in an electric slide gate valve.

[0042] The beneficial effects of this application include, but are not limited to: 1. The high oil resistance and high sealing performance composite material of this application adopts a ternary blend of fluorosilicone rubber raw rubber, fluororubber and nitrile rubber to construct the matrix, and is combined with reinforcing fillers, modified molybdenum disulfide-graphene oxide interface reinforcing fillers and other auxiliary agents. It effectively solves the technical problem that it is difficult to achieve the same oil resistance, sealing and mechanical properties of single rubber, and realizes the comprehensive advantages of high oil resistance, high sealing, high mechanical strength and aging resistance of composite material.

[0043] 2. According to the high oil resistance and high sealing performance composite material of this application, molybdenum disulfide is mixed with graphene oxide after oxygen plasma treatment, and modified by adding silane coupling agent, which effectively improves the interfacial bonding force between inorganic filler and organic rubber matrix, solves the filler agglomeration problem, and constructs a two-dimensional sheet barrier network, which significantly improves the oil penetration resistance and wear resistance of the composite material.

[0044] 3. According to the high oil resistance and high sealing performance composite material of this application, the addition of microporous foaming agent makes the composite material form a uniform and fine closed-cell structure, which not only improves the sealing fit and elastic rebound ability, but also reduces the material weight, thus achieving a dual improvement in sealing performance and ease of use.

[0045] 4. According to the preparation method of the high oil resistance and high sealing performance composite material of this application, the step-by-step mixing and open milling process is adopted, combined with the three-stage step vulcanization process, which realizes the blending of rubber, uniform dispersion of fillers, and synergistic foaming and vulcanization reactions, avoiding problems such as premature failure of heat-sensitive additives and collapse of cell structure. Detailed Implementation

[0046] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0047] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this application were all purchased commercially.

[0048] Unless otherwise specified, the methods used in the embodiments and comparative examples of this application are conventional methods in the prior art.

[0049] Example 1 This embodiment relates to a method for preparing a composite material with high oil resistance and high sealing performance, characterized by comprising the following steps: (1) 60 parts of fluorosilicone rubber raw rubber (molar content of vinyl is 0.2%), 10 parts of fluororubber 26 (Mooney viscosity is 30M) and 5 parts of nitrile rubber (acrylonitrile content is 30wt%) were mechanically blended and plasticized in an internal mixer for 5 min at a temperature of 80℃ and a pressure of 0.5MPa to obtain a rubber matrix; (2) Add 15 parts of fumed silica and 5 parts of interfacial reinforcing filler to the matrix in sequence, mix for 10 min to obtain the first compound, the temperature is 100℃ and the pressure is 0.6MPa. (3) After the first compound is transferred to the open mill and passed through it three times at 60°C, 2 parts of microporous foaming agent (sodium bicarbonate, azodicarbonamide and zinc oxide in a mass ratio of 1:1:1), 2 parts of vulcanizing agent diisopropylbenzene peroxide, 1 part of antioxidant RD and 0.5 parts of internal release agent stearic acid are added. After mixing at 60°C for 10 minutes, the second compound is obtained. (4) The second compound is pre-cured at 150°C and 5 MPa for 15 min; then vulcanized at 170°C and 10 MPa for 30 min; and finally vulcanized at 180°C and 10 MPa for 5 h to obtain the product.

[0050] The preparation of the interface-reinforcing filler includes the following steps: Molybdenum disulfide was treated with oxygen plasma for 5 min at an oxygen flow rate of 100 mL / min and a power of 150 W. It was then mixed with graphene oxide (9 layers, with a molar content of 30% oxygen-containing functional groups) and γ-aminopropyltriethoxysilane. The mixture was ball-milled for 1 h at a speed of 400 rpm using anhydrous ethanol as the dispersion medium. After the mixture was finished, it was dried in a vacuum drying oven to remove the anhydrous ethanol. The mass ratio of molybdenum disulfide to graphene oxide was 1:1, and the amount of γ-aminopropyltriethoxysilane added was 1% of the total mass of molybdenum disulfide and graphene oxide.

[0051] Example 2 This embodiment relates to a method for preparing a composite material with high oil resistance and high sealing performance, characterized by comprising the following steps: (1) 90 parts of fluorosilicone rubber raw rubber (2% molar content of vinyl), 30 parts of fluororubber 26 (Mooney viscosity of 60M) and 10 parts of nitrile rubber (50wt% content of acrylonitrile) were mechanically blended and plasticized in an internal mixer for 5 min at a temperature of 80℃ and a pressure of 0.5MPa to obtain a rubber matrix. (2) Add 30 parts of fumed silica and 15 parts of interfacial reinforcing filler to the matrix in sequence, mix for 10 min to obtain the first compound, the temperature is 100℃ and the pressure is 0.6MPa. (3) After transferring the first compound to a two-roll mill and passing it through a thin mill three times at 60°C, add 6 parts of microporous foaming agent (sodium bicarbonate, azodicarbonamide, and zinc oxide in a mass ratio of 1:1.5:2), 6 parts of vulcanizing agent 2,5-dimethyl-2,5-di-tert-butylperoxide, 3 parts of antioxidant 4010NA, and 1.5 parts of internal release agent zinc stearate. After mixing at 60°C for 10 minutes, the second compound is obtained. (4) The second compound is pre-cured at 170°C and 10 MPa for 5 min; then vulcanized at 190°C and 20 MPa for 15 min; and finally vulcanized at 200°C and 20 MPa for 2 h to obtain the final product.

[0052] The preparation of the interface-reinforcing filler includes the following steps: Molybdenum disulfide was treated with oxygen plasma for 15 min at an oxygen flow rate of 50 mL / min and a power of 50 W. This mixture was then combined with graphene oxide (7 layers, with a molar content of 50% oxygen-containing functional groups) and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane. The mixture was ball-milled for 4 h at 200 rpm using anhydrous ethanol as the dispersion medium. After the milling process, it was dried in a vacuum drying oven to remove the anhydrous ethanol, yielding the product. The mass ratio of molybdenum disulfide to graphene oxide was 1.2:1, and the amount of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane added was 3% of the total mass of molybdenum disulfide and graphene oxide.

[0053] Example 3 This embodiment relates to a method for preparing a composite material with high oil resistance and high sealing performance, characterized by comprising the following steps: (1) 75 parts of fluorosilicone rubber raw rubber (1% molar content of vinyl), 30 parts of fluororubber 246 (Mooney viscosity of 50M) and 6 parts of nitrile rubber (45wt% content of acrylonitrile) were mechanically blended and plasticized in an internal mixer for 5 minutes at a temperature of 80℃ and a pressure of 0.5MPa to obtain a rubber matrix. (2) 25 parts of fumed silica and 12 parts of interfacial reinforcing filler were added to the matrix in sequence, and the first compound was obtained after mixing for 10 min at a temperature of 100℃ and a pressure of 0.6MPa. (3) After transferring the first compound to a two-roll mill and passing it through a thin mill three times at 60°C, add 4 parts of microporous foaming agent (sodium bicarbonate, azodicarbonamide, and zinc oxide in a mass ratio of 1:1.2:1.6), 4 parts of vulcanizing agent benzoyl peroxide, 2 parts of antioxidant 4020, and 1 part of inner release agent zinc stearate. After mixing at 60°C for 10 minutes, the second compound is obtained. (4) The second compound is pre-cured at 160°C and 8MPa for 10 min; then vulcanized at 180°C and 15MPa for 20 min; and finally vulcanized at 200°C and 15MPa for 3.5 h to obtain the final product.

[0054] The preparation of the interface-reinforcing filler includes the following steps: Molybdenum disulfide was treated with oxygen plasma for 10 min at an oxygen flow rate of 80 mL / min and a power of 100 W. This mixture was then combined with graphene oxide (8 layers, with a molar content of 40% oxygen-containing functional groups) and γ-methacryloyloxypropyltrimethoxysilane. The mixture was ball-milled for 3 h at 300 rpm using anhydrous ethanol as the dispersion medium. After the milling process, it was dried in a vacuum drying oven to remove the anhydrous ethanol, yielding the product. The mass ratio of molybdenum disulfide to graphene oxide was 1.1:1, and the amount of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane added was 2% of the total mass of molybdenum disulfide and graphene oxide.

[0055] Example 4 The difference between this embodiment and Embodiment 3 is that the amount of fluororubber is 10 parts, while the rest are the same.

[0056] Example 5 The difference between this embodiment and Embodiment 3 is that the amount of nitrile rubber is 5 parts, while the rest are the same.

[0057] Example 6 The difference between this embodiment and Embodiment 3 is that the molar content of vinyl groups in the fluorosilicone rubber raw rubber is 3%, while the rest are the same.

[0058] Example 7 The difference between this embodiment and Embodiment 3 is that the Mooney viscosity of fluororubber 246 is 70M, while the rest are the same.

[0059] Example 8 The difference between this embodiment and Embodiment 3 is that the acrylonitrile content in the nitrile rubber is 55 wt%, while the rest are the same.

[0060] Example 9 The difference between this embodiment and Embodiment 3 is that the mass ratio of molybdenum disulfide to graphene oxide is 0.8:1, while all other aspects are the same.

[0061] Example 10 The difference between this embodiment and Embodiment 3 is that the mass ratio of molybdenum disulfide to graphene oxide is 1.5:1, while all other aspects are the same.

[0062] Example 11 The difference between this embodiment and Embodiment 3 is that molybdenum disulfide is not treated with oxygen plasma, but all other aspects are the same.

[0063] Example 12 The difference between this embodiment and Embodiment 3 is that the number of graphene oxide layers is 10, while the rest are the same.

[0064] Example 13 The difference between this embodiment and Embodiment 3 is that the mass ratio of sodium bicarbonate, azodicarbonamide, and zinc oxide in the microporous foaming agent is 1:1.8:1.6, while the rest are the same.

[0065] Example 14 The difference between this embodiment and Embodiment 3 is that the mass ratio of sodium bicarbonate, azodicarbonamide, and zinc oxide in the microporous foaming agent is 1:0.8:1.6, while the rest are the same.

[0066] Example 15 The difference between this embodiment and Embodiment 3 is that the mass ratio of sodium bicarbonate, azodicarbonamide, and zinc oxide in the microporous foaming agent is 1:1.2:0.6, while the rest are the same.

[0067] Example 16 The difference between this embodiment and Embodiment 3 is that the mass ratio of sodium bicarbonate, azodicarbonamide, and zinc oxide in the microporous foaming agent is 1:1.2:2.4, while the rest are the same.

[0068] Example 17 The difference between this embodiment and Embodiment 3 is that there is no pre-vulcanization step; all other aspects are the same.

[0069] Comparative Example 1 The difference between this comparative example and Example 3 is that fluororubber is not added; all other aspects are the same.

[0070] Comparative Example 2 The difference between this comparative example and Example 3 is that nitrile rubber is not added; all other aspects are the same.

[0071] Comparative Example 3 The difference between this comparative example and Example 3 is that the interface-enhancing filler is 18 parts, while the rest are the same.

[0072] Comparative Example 4 The difference between this comparative example and Example 3 is that the microporous foaming agent is 8 parts, while the rest are the same.

[0073] Comparative Example 5 The difference between this comparative example and Example 3 is that the interface reinforcing filler is a compound of molybdenum disulfide and graphene oxide, without modification treatment; all other aspects are the same.

[0074] Comparative Example 6 The difference between this comparative example and Example 3 is that ordinary graphene is used instead of graphene oxide; all other aspects are the same.

[0075] Test Example 1 The composite materials prepared in the above embodiments and comparative examples were subjected to mechanical property and sealing tests. The mechanical property tests were conducted in accordance with standard GB / T-528-2009, and the sealing tests were conducted in accordance with standard GB / T 7759.1-2015. The results are shown in Table 1.

[0076] Table 1

[0077] Test Example 2 After preparing the composite materials in the above examples and comparative examples, the oil resistance properties were tested. The test method was carried out in accordance with the standard GB / T1690-2006, and the conditions were 150℃×10h. The results are shown in Table 2.

[0078] Table 2

[0079] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. A composite material with high oil resistance and high sealing performance, characterized in that, By weight, it includes 60-90 parts of fluorosilicone rubber raw rubber, 10-30 parts of fluororubber, 5-10 parts of nitrile rubber, 15-30 parts of reinforcing filler, 5-15 parts of interface reinforcing filler, 2-6 parts of microporous foaming agent, 2-6 parts of vulcanizing agent, 1-3 parts of antioxidant, and 0.5-1.5 parts of internal release agent. The interface-enhancing filler is a modified compound of molybdenum disulfide and graphene oxide.

2. The composite material with high oil resistance and high sealing performance according to claim 1, characterized in that, The mass ratio of the fluororubber to the nitrile rubber is (2-5):

1.

3. The composite material with high oil resistance and high sealing performance according to claim 1, characterized in that, The molar content of vinyl groups in the fluorosilicone rubber raw material is 0.2-2%; and / or The fluororubber is a vinylidene fluoride-based rubber with a Mooney viscosity of 30-60 M; and / or The acrylonitrile content in the nitrile rubber is 30-50 wt%.

4. The high oil resistance and high sealing performance composite material according to claim 1, characterized in that, The preparation of the interface-reinforcing filler includes the following steps: Molybdenum disulfide was treated with oxygen plasma, then mixed with graphene oxide and silane coupling agent, and ball-milled for 1-4 hours with anhydrous ethanol as the dispersion medium at a speed of 200-400 rpm. After the process, the anhydrous ethanol was removed to obtain the final product. The mass ratio of molybdenum disulfide to graphene oxide is (1-1.2):1, and the amount of silane coupling agent added is 1-3% of the total mass of molybdenum disulfide and graphene oxide.

5. The composite material with high oil resistance and high sealing performance according to claim 4, characterized in that, The graphene oxide has fewer than 10 layers and contains 30-50% molar content of oxygen-containing functional groups.

6. The composite material with high oil resistance and high sealing performance according to claim 1, characterized in that, The microporous foaming agent is sodium bicarbonate, azodicarbonamide, and zinc oxide in a mass ratio of 1:(1-1.5):(1-2).

7. The high oil resistance and high sealing performance composite material according to claim 1, characterized in that, The reinforcing filler is fumed silica; The vulcanizing agent is at least one of dicumyl peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxide, benzoyl peroxide, and bis(2,4-dichlorobenzoyl) peroxide; The antioxidant is at least one of antioxidant RD, antioxidant 4010NA, antioxidant 4020, antioxidant 1010, and antioxidant 1076; The internal release agent is zinc stearate or stearic acid.

8. A method for preparing the high oil resistance and high sealing performance composite material according to any one of claims 1-7, characterized in that, Includes the following steps: (1) Fluorosilicone rubber raw rubber, fluororubber and nitrile rubber are mechanically blended and plasticized in an internal mixer to obtain a rubber matrix; (2) Reinforcing filler and interface reinforcing filler are added to the matrix in sequence, and the first compound is obtained after mixing. (3) Transfer the first compound to a two-roll mill, add microporous foaming agent, vulcanizing agent, antioxidant and internal release agent, and mix to obtain the second compound; (4) The second compound is vulcanized to obtain the final product.

9. The composite material with high oil resistance and high sealing performance according to claim 8, characterized in that, The vulcanization described in step (4) is as follows: pre-vulcanization at 150-170℃ and 5-10 MPa for 5-15 min; then first-stage vulcanization at 170-190℃ and 10-20 MPa for 15-30 min; and finally second-stage vulcanization at 180-200℃ and 10-20 MPa for 2-5 h.

10. The application of the composite material with high oil resistance and high sealing performance according to any one of claims 1-7 or the composite material with high oil resistance and high sealing performance according to any one of claims 8-9 in an electric slide gate valve.

Images