Rubber material for rubber sealing ring and preparation method thereof

Abstract

The invention relates to the field of rubber, and provides a rubber material for a rubber sealing ring and a preparation method of the rubber material. The rubber material for the rubber sealing ring is prepared from the following raw materials in parts by weight: 60-70 parts of fluorinated silicone rubber, 30-40 parts of hydrogenated nitrile rubber, 5-8 parts of modified graphene nanosheets, 3-5 parts of a plasticizer, 10-15 parts of a halogen-free flame retardant, 2-4 parts of self-repairing microcapsules, 1.5-2.5 parts of a cross-linking agent and 2-3 parts of cerium oxide. The rubber material for the rubber sealing ring provided by the invention aims to improve the temperature resistance, wear resistance and chemical medium corrosion resistance of the rubber sealing ring so as to meet wider application requirements.

Description

Technical Field

[0001] The present invention relates to the field of rubber technology, and in particular to a rubber material for a rubber sealing ring and a preparation method thereof. Background Art

[0002] As a key component to ensure the sealing performance and safe operation of equipment, rubber sealing rings are widely used in many industries such as automobiles, aerospace, petroleum and petrochemicals, and machinery manufacturing. The selection and preparation method of rubber materials have a crucial impact on the performance of rubber sealing rings.

[0003] At present, the commonly used materials for rubber seals include natural rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, etc. These rubber materials have different physical and chemical properties, such as elasticity, hardness, heat resistance, oil resistance, etc. However, there are still some technical problems with existing rubber seal materials. Some rubber materials are easy to deform or harden under high or low temperature environments, resulting in reduced sealing performance. For example, natural rubber is easy to soften at high temperatures, while chloroprene rubber is easy to harden at low temperatures; in friction and wear environments, rubber seals are easy to wear, shortening their service life. Although polyurethane rubber has high wear resistance, its high cost limits its wide application; some rubber materials will swell, dissolve or age when in contact with specific chemical media, resulting in failure of sealing performance. For example, although nitrile rubber has good oil resistance, it performs poorly in corrosive media such as strong acids and alkalis.

[0004] The technical problems of existing rubber sealing ring materials mainly stem from the limitations of their chemical structure and physical properties. The lack of temperature resistance is due to the fact that the rubber molecular chain is prone to thermal movement at high temperatures, resulting in material deformation; the poor wear resistance is related to the hardness and roughness of the rubber surface; the limited resistance to chemical corrosion is due to the reaction of certain functional groups in the rubber molecular chain with the chemical medium, resulting in a decrease in material performance. Based on this, the present invention proposes a rubber material for a rubber sealing ring and a preparation method thereof. Summary of the invention

[0005] The invention provides a rubber material for a rubber sealing ring and a preparation method thereof, which optimizes the temperature resistance, wear resistance and chemical medium resistance of the rubber material.

[0006] The technical solution of the present invention is as follows: In a first aspect, the present invention proposes a rubber material for a rubber sealing ring, which is composed of the following raw materials in parts by weight: 60-70 parts of fluorosilicone rubber, 30-40 parts of hydrogenated nitrile rubber, 5-8 parts of modified graphene nanosheets, 3-5 parts of plasticizer, 10-15 parts of halogen-free flame retardant, 2-4 parts of self-healing microcapsules, 1.5-2.5 parts of cross-linking agent and 2-3 parts of cerium oxide.

[0007] As a further technical solution, the preparation method of the modified graphene nanosheets includes: vacuum drying graphene oxide at 80-90°C for 10-12 hours, dispersing the dried graphene oxide in acetone, and ultrasonically forming a uniform dispersion; under nitrogen protection, slowly adding toluene diisocyanate to the dispersion at a temperature of 25-30°C; continuously stirring at 900-1000rpm, and reacting for 20-24 hours under the assistance of ultrasound to form hydrophobic modified graphene; after the reaction, adding ethanol to precipitate the product, filtering, washing, and drying to obtain modified graphene nanosheets.

[0008] As a further technical solution, the weight ratio of the graphene oxide, acetone, toluene diisocyanate and ethanol is 1:28-32:45-55:120-140.

[0009] As a further technical solution, the core material of the self-repairing microcapsule is a silane coupling agent, the shell material is polyurethane, and the particle size of the self-repairing microcapsule is 10-50 μm.

[0010] After the microcapsules rupture, the silane coupling agent (KH-550) is released, and its Si-OCH3 group is hydrolyzed to generate Si-OH, which condenses with the hydroxyl group on the rubber surface to form Si-O-Si bonds, thus repairing the wear microcracks.

[0011] As a further technical solution, the preparation method of the self-healing microcapsule includes: dispersing the silane coupling agent core material in a mixed solution of ethanol and water containing an emulsifier Span-80, stirring at high speed to form an emulsion, adding a polyurethane shell material solution dissolved in ethyl acetate, reacting at 50-60°C for 3-4 hours, and after the reaction, filtering the microcapsule suspension, washing it with deionized water 3 times, and vacuum drying it at 40-50°C to obtain self-healing microcapsules with a particle size of 10-50μm.

[0012] As a further technical solution, the preparation method of the core material comprises: mixing a silane coupling agent KH-550 and a dibutyltin dilaurate catalyst in a weight ratio of 0.5:95-105 to obtain the core material.

[0013] As a further technical solution, the method for preparing the shell material comprises: mixing hexamethylene diisocyanate and polyether polyol in a molar ratio of 1:2-3 to obtain the shell material.

[0014] As a further technical solution, the weight ratio of the silane coupling agent core material, emulsifier Span-80, ethanol and water is 9-11:0.5-1.5:85-95:9-11; the weight ratio of the shell material and ethyl acetate in the ethyl acetate polyurethane shell material solution is 1:4-5; the weight ratio of the emulsion and the polyurethane shell material solution is 4-6:1.

[0015] As a further technical solution, the plasticizer is epoxy triglyceride; the model of the halogen-free flame retardant is Exolit OP1312; and the cross-linking agent is bisphenol AF.

[0016] In the second aspect, the present invention proposes a method for preparing a rubber material for a rubber sealing ring, the steps comprising: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 120-140°C and a rotation speed of 200-300rpm; adding modified graphene nanosheets and cerium oxide, and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer, halogen-free flame retardant, and self-healing microcapsule into an internal mixer and mixing for 10-15min at a temperature of 80-90°C; then vulcanizing at a pressure of 10-15MPa and a temperature of 150-160°C for 8-10min, and then vulcanizing at 190-210°C for 3-4h to obtain the product.

[0017] The working principle and beneficial effects of the present invention are: The fluorosilicone rubber in the present invention has excellent high and low temperature resistance and chemical stability, while the hydrogenated nitrile rubber has good oil resistance and heat aging resistance. The two are co-mixed and extruded in a twin-screw extruder, so that the two rubber molecular chains are entangled with each other to form a more compact network structure, thereby improving the overall temperature resistance of the rubber material. In addition, the modified graphene nanosheet has extremely high thermal conductivity and mechanical strength, can form an effective heat conduction path in the rubber matrix, accelerate the dissipation of heat, and enhance the mechanical properties of the rubber material, further improving the temperature resistance.

[0018] The high hardness and wear resistance of the modified graphene nanosheets in the present invention and the microscopic filling effect of cerium oxide jointly enhance the hardness and wear resistance of the rubber surface and reduce the wear during the friction process. Therefore, the modified graphene nanosheets and cerium oxide have a synergistic effect; and the oil resistance of hydrogenated nitrile rubber helps to reduce swelling and wear in oily media, further improving the wear resistance.

[0019] In the present invention, toluene diisocyanate is used to hydrophobically modify graphene. Toluene diisocyanate can react with hydroxyl and carboxyl groups on the surface of graphene oxide to form hydrophobic groups, thereby improving the dispersibility of graphene in the rubber matrix. Good dispersibility is the key to ensuring the graphene enhancement effect. The interface interaction between the hydrophobically modified graphene and the rubber matrix is ​​enhanced, which helps to improve the overall mechanical properties and temperature resistance of the rubber material.

[0020] In the present invention, the core material is selected from silane coupling agents, wherein the silane coupling agent has good chemical activity and reactivity, and can react quickly with the surrounding rubber molecular chains when the rubber material is damaged to promote the healing of cracks. In addition, the silane coupling agent can also enhance the mechanical properties of the rubber material to a certain extent. The shell material is selected from polyurethane, which has good flexibility and resistance to chemical media, can protect the core material from damage by the external environment, and ensure that the core material can be released smoothly when needed. Through the steps of forming an emulsion by high-speed stirring, slowly adding the shell material solution, and controlling the reaction temperature and time, it is ensured that the particle size of the self-repairing microcapsules is uniform, the shell layer is complete, and the core material content is moderate. This optimized preparation process helps to improve the repair efficiency and stability of the self-repairing microcapsules.

[0021] The present invention utilizes the compounding effect of modified graphene nanosheets and self-repairing microcapsules. The self-repairing microcapsules can release the core material (silane coupling agent) when the rubber material is damaged, promote the healing of cracks, and thus improve the self-repairing ability and service life of the rubber material. This intelligent repair mechanism complements the strengthening effect of the modified graphene nanosheets and jointly improves the overall performance of the rubber material. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the following examples and comparative examples, the polyether polyol model is VORANOL 2000LM.

[0024] Example 1 The present embodiment provides a rubber material for a rubber sealing ring, which is composed of the following raw materials in parts by weight: 65 parts of fluorosilicone rubber, 35 parts of hydrogenated nitrile rubber, 6 parts of modified graphene nanosheets, 4 parts of plasticizer, 12 parts of halogen-free flame retardant, 3 parts of self-healing microcapsules, 2 parts of cross-linking agent and 2.5 parts of cerium oxide; The preparation method of modified graphene nanosheets includes: vacuum drying graphene oxide at 85°C for 11 hours, dispersing the dried graphene oxide in acetone, and ultrasonically treating at 40kHz for 35 minutes to form a uniform dispersion; slowly adding toluene diisocyanate to the dispersion at 27°C under nitrogen protection; continuously stirring at 950rpm, and reacting for 22 hours under 35kHz ultrasonic assistance to form hydrophobic modified graphene; after the reaction, adding ethanol to precipitate the product, and the weight ratio of graphene oxide, acetone, toluene diisocyanate and ethanol is 1:30:50:130; after filtering, washing with ethanol three times, and vacuum drying at 55°C for 11 hours to obtain modified graphene nanosheets; The preparation method of the self-healing microcapsule includes: mixing a silane coupling agent KH-550 and a catalyst dibutyltin dilaurate in a weight ratio of 0.5:100 to obtain a core material; mixing hexamethylene diisocyanate and polyether polyol in a molar ratio of 1:2.5 to obtain a shell material; dispersing the silane coupling agent core material in a mixed solution of ethanol and water containing an emulsifier Span-80, stirring at a high speed to form an emulsion, slowly adding a polyurethane shell material solution dissolved in ethyl acetate, reacting at 55°C for 3.5 hours, filtering the microcapsule suspension after the reaction, washing with deionized water for 3 times, and vacuum drying at 45°C to obtain a self-healing microcapsule with a particle size of 30 μm; the weight ratio of the silane coupling agent core material, the emulsifier Span-80, ethanol, and water is 10:1:90:10; the weight ratio of the shell material and ethyl acetate in the polyurethane shell material solution of ethyl acetate is 1:4.5; the weight ratio of the emulsion and the polyurethane shell material solution is 5:1; The plasticizer is epoxy triglyceride; the halogen-free flame retardant is Exolit OP1312, purchased from Clariant Specialty Chemicals; the crosslinker is bisphenol AF; The preparation method of the rubber material for the rubber sealing ring comprises the following steps: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 130°C and a rotation speed of 250rpm; adding modified graphene nanosheets and cerium oxide, and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer, halogen-free flame retardant, and self-repairing microcapsules into an internal mixer and mixing for 12 minutes at a temperature of 85°C; then vulcanizing for 9 minutes at a pressure of 12MPa and a temperature of 155°C, and then vulcanizing for 3.5 hours at 200°C to obtain the rubber material for the rubber sealing ring.

[0025] Example 2 The present embodiment provides a rubber material for a rubber sealing ring, which is composed of the following raw materials in parts by weight: 60 parts of fluorosilicone rubber, 30 parts of hydrogenated nitrile rubber, 5 parts of modified graphene nanosheets, 3 parts of plasticizer, 10 parts of halogen-free flame retardant, 2 parts of self-repairing microcapsules, 1.5 parts of cross-linking agent and 2 parts of cerium oxide; The preparation method of modified graphene nanosheets includes: vacuum drying graphene oxide at 80°C for 10 hours, dispersing the dried graphene oxide in acetone, and ultrasonically treating at 40kHz for 30 minutes to form a uniform dispersion; slowly adding toluene diisocyanate to the dispersion at 25°C under nitrogen protection; continuously stirring at 900rpm, and reacting for 20 hours under 30kHz ultrasonic assistance to form hydrophobic modified graphene; after the reaction, adding ethanol to precipitate the product, and the weight ratio of graphene oxide, acetone, toluene diisocyanate and ethanol is 1:28:45:120; after filtering, washing with ethanol for 3 times, and vacuum drying at 50°C for 10 hours to obtain modified graphene nanosheets; The preparation method of the self-healing microcapsule includes: mixing a silane coupling agent KH-550 and a catalyst dibutyltin dilaurate in a weight ratio of 0.5:95 to obtain a core material; mixing hexamethylene diisocyanate and polyether polyol in a molar ratio of 1:2 to obtain a shell material; dispersing the silane coupling agent core material in a mixed solution of ethanol and water containing an emulsifier Span-80, stirring at a high speed to form an emulsion, slowly adding a polyurethane shell material solution dissolved in ethyl acetate, reacting at 50°C for 3 hours, filtering the microcapsule suspension after the reaction, washing with deionized water for 3 times, and vacuum drying at 40°C to obtain a self-healing microcapsule with a particle size of 30 μm; the weight ratio of the silane coupling agent core material, the emulsifier Span-80, ethanol, and water is 9:0.5:85:9; the weight ratio of the shell material and ethyl acetate in the polyurethane shell material solution of ethyl acetate is 1:4; the weight ratio of the emulsion and the polyurethane shell material solution is 4:1; The plasticizer is epoxy triglyceride; the halogen-free flame retardant is Exolit OP1312, purchased from Clariant Specialty Chemicals; the crosslinker is bisphenol AF; The preparation method of the rubber material for the rubber sealing ring comprises the following steps: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 120°C and a rotation speed of 200 rpm; adding modified graphene nanosheets and cerium oxide, and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer, halogen-free flame retardant, and self-repairing microcapsules into an internal mixer and mixing for 10 minutes at a temperature of 80°C; then vulcanizing for 8 minutes at a pressure of 10 MPa and a temperature of 150°C, and then vulcanizing for 3 hours at 190°C to obtain the rubber material for the rubber sealing ring.

[0026] Example 3 The present embodiment provides a rubber material for a rubber sealing ring, which is composed of the following raw materials in parts by weight: 70 parts of fluorosilicone rubber, 40 parts of hydrogenated nitrile rubber, 8 parts of modified graphene nanosheets, 5 parts of plasticizer, 15 parts of halogen-free flame retardant, 4 parts of self-repairing microcapsules, 2.5 parts of cross-linking agent and 3 parts of cerium oxide; The preparation method of modified graphene nanosheets includes: vacuum drying graphene oxide at 90°C for 12 hours, dispersing the dried graphene oxide in acetone, and ultrasonically treating at 40kHz for 40 minutes to form a uniform dispersion; slowly adding toluene diisocyanate to the dispersion at 30°C under nitrogen protection; continuously stirring at 1000rpm, and reacting for 24 hours under 40kHz ultrasonic assistance to form hydrophobic modified graphene; after the reaction, adding ethanol to precipitate the product, and the weight ratio of graphene oxide, acetone, toluene diisocyanate and ethanol is 1:32:55:140; filtering, washing with ethanol three times, and vacuum drying at 60°C for 12 hours to obtain modified graphene nanosheets; The preparation method of the self-healing microcapsule includes: mixing a silane coupling agent KH-550 and a catalyst dibutyltin dilaurate in a weight ratio of 0.5:105 to obtain a core material; mixing hexamethylene diisocyanate and polyether polyol in a molar ratio of 1:3 to obtain a shell material; dispersing the silane coupling agent core material in a mixed solution of ethanol and water containing an emulsifier Span-80, stirring at high speed to form an emulsion, slowly adding a polyurethane shell material solution dissolved in ethyl acetate, reacting at 60°C for 4 hours, filtering the microcapsule suspension after the reaction, washing with deionized water for 3 times, and vacuum drying at 50°C to obtain a self-healing microcapsule with a particle size of 30 μm; the weight ratio of the silane coupling agent core material, the emulsifier Span-80, ethanol, and water is 11:1.5:95:11; the weight ratio of the shell material and ethyl acetate in the polyurethane shell material solution of ethyl acetate is 1:5; the weight ratio of the emulsion and the polyurethane shell material solution is 6:1; The plasticizer is epoxy triglyceride; the halogen-free flame retardant is Exolit OP1312, purchased from Clariant Specialty Chemicals; the crosslinker is bisphenol AF; The preparation method of the rubber material for the rubber sealing ring comprises the following steps: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 140°C and a rotation speed of 300 rpm; adding modified graphene nanosheets and cerium oxide, and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer, halogen-free flame retardant, and self-repairing microcapsules into an internal mixer and mixing for 15 minutes at a temperature of 90°C; then vulcanizing for 10 minutes at a pressure of 15 MPa and a temperature of 160°C, and then vulcanizing for 4 hours at 210°C to obtain the rubber material for the rubber sealing ring.

[0027] Example 4 The present embodiment provides a rubber material for a rubber sealing ring, which is composed of the following raw materials in parts by weight: 60 parts of fluorosilicone rubber, 40 parts of hydrogenated nitrile rubber, 5 parts of modified graphene nanosheets, 5 parts of plasticizer, 10 parts of halogen-free flame retardant, 4 parts of self-repairing microcapsules, 1.5 parts of cross-linking agent and 3 parts of cerium oxide; The preparation method of modified graphene nanosheets includes: vacuum drying graphene oxide at 80°C for 12 hours, dispersing the dried graphene oxide in acetone, and ultrasonically treating at 40kHz for 30 minutes to form a uniform dispersion; slowly adding toluene diisocyanate to the dispersion at 30°C under nitrogen protection; continuously stirring at 900rpm, and reacting for 20 hours under 40kHz ultrasonic assistance to form hydrophobic modified graphene; after the reaction, adding ethanol to precipitate the product, and the weight ratio of graphene oxide, acetone, toluene diisocyanate and ethanol is 1:32:45:140; after filtering, washing with ethanol three times, and vacuum drying at 50°C for 12 hours to obtain modified graphene nanosheets; The preparation method of the self-repairing microcapsule includes: mixing a silane coupling agent KH-550 and a catalyst dibutyltin dilaurate in a weight ratio of 0.5:95 to obtain a core material; mixing hexamethylene diisocyanate and polyether polyol in a molar ratio of 1:3 to obtain a shell material; dispersing the silane coupling agent core material in a mixed solution of ethanol and water containing an emulsifier Span-80, stirring at a high speed to form an emulsion, slowly adding a polyurethane shell material solution dissolved in ethyl acetate, reacting at 50°C for 4 hours, filtering the microcapsule suspension after the reaction, washing with deionized water for 3 times, and vacuum drying at 40°C to obtain a self-repairing microcapsule with a particle size of 30 μm; the weight ratio of the silane coupling agent core material, the emulsifier Span-80, ethanol, and water is 9:1.5:85:11; the weight ratio of the shell material and ethyl acetate in the polyurethane shell material solution of ethyl acetate is 1:4; the weight ratio of the emulsion and the polyurethane shell material solution is 6:1; The plasticizer is epoxy triglyceride; the halogen-free flame retardant is Exolit OP1312, purchased from Clariant Specialty Chemicals; the crosslinker is bisphenol AF; The preparation method of the rubber material for the rubber sealing ring comprises the following steps: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 140°C and a rotation speed of 200 rpm; adding modified graphene nanosheets and cerium oxide, and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer, halogen-free flame retardant, and self-repairing microcapsules into an internal mixer and mixing for 10 minutes at a temperature of 90°C; then vulcanizing for 10 minutes at a pressure of 15MPa and a temperature of 150°C, and then vulcanizing for 4 hours at 190°C to obtain the rubber material for the rubber sealing ring.

[0028] Comparative Example 1 In this comparative example, a rubber material for a rubber sealing ring is provided, which is composed of the following raw materials in parts by weight: 65 parts of fluorosilicone rubber, 35 parts of hydrogenated nitrile rubber, 4 parts of plasticizer, 12 parts of halogen-free flame retardant, 3 parts of self-repairing microcapsules, 2 parts of cross-linking agent and 2.5 parts of cerium oxide; The preparation method of the self-healing microcapsule includes: mixing a silane coupling agent KH-550 and a catalyst dibutyltin dilaurate in a weight ratio of 0.5:100 to obtain a core material; mixing hexamethylene diisocyanate and polyether polyol in a molar ratio of 1:2.5 to obtain a shell material; dispersing the silane coupling agent core material in a mixed solution of ethanol and water containing an emulsifier Span-80, stirring at a high speed to form an emulsion, slowly adding a polyurethane shell material solution dissolved in ethyl acetate, reacting at 55°C for 3.5 hours, filtering the microcapsule suspension after the reaction, washing with deionized water for 3 times, and vacuum drying at 45°C to obtain a self-healing microcapsule with a particle size of 30 μm; the weight ratio of the silane coupling agent core material, the emulsifier Span-80, ethanol, and water is 10:1:90:10; the weight ratio of the shell material and ethyl acetate in the polyurethane shell material solution of ethyl acetate is 1:4.5; the weight ratio of the emulsion and the polyurethane shell material solution is 5:1; The plasticizer is epoxy triglyceride; the halogen-free flame retardant is Exolit OP1312, purchased from Clariant Specialty Chemicals; the crosslinker is bisphenol AF; The preparation method of the rubber material for the rubber sealing ring comprises the following steps: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 130°C and a rotation speed of 250rpm; adding cerium oxide and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer, halogen-free flame retardant and self-repairing microcapsule into an internal mixer and mixing for 12 minutes at a temperature of 85°C; then vulcanizing at a pressure of 12MPa and a temperature of 155°C for 9 minutes, and then vulcanizing at 200°C for 3.5 hours to obtain the rubber material for the rubber sealing ring.

[0029] Comparative Example 2 In this comparative example, a rubber material for a rubber sealing ring is provided, which is composed of the following raw materials in parts by weight: 65 parts of fluorosilicone rubber, 35 parts of hydrogenated nitrile rubber, 6 parts of modified graphene nanosheets, 4 parts of plasticizer, 12 parts of halogen-free flame retardant, 2 parts of cross-linking agent and 2.5 parts of cerium oxide; The preparation method of modified graphene nanosheets includes: vacuum drying graphene oxide at 85°C for 11 hours, dispersing the dried graphene oxide in acetone, and ultrasonically treating at 40kHz for 35 minutes to form a uniform dispersion; slowly adding toluene diisocyanate to the dispersion at 27°C under nitrogen protection; continuously stirring at 950rpm, and reacting for 22 hours under 35kHz ultrasonic assistance to form hydrophobic modified graphene; after the reaction, adding ethanol to precipitate the product, and the weight ratio of graphene oxide, acetone, toluene diisocyanate and ethanol is 1:30:50:130; after filtering, washing with ethanol three times, and vacuum drying at 55°C for 11 hours to obtain modified graphene nanosheets; The plasticizer is epoxy triglyceride; the halogen-free flame retardant is Exolit OP1312, purchased from Clariant Specialty Chemicals; the crosslinker is bisphenol AF; The preparation method of the rubber material for the rubber sealing ring comprises the following steps: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 130°C and a rotation speed of 250rpm; adding modified graphene nanosheets and cerium oxide, and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer, and halogen-free flame retardant into an internal mixer and mixing for 12 minutes at a temperature of 85°C; then vulcanizing for 9 minutes at a pressure of 12MPa and a temperature of 155°C, and then vulcanizing for 3.5 hours at 200°C to obtain the rubber material for the rubber sealing ring.

[0030] Comparative Example 3 In this comparative example, a rubber material for a rubber sealing ring is provided, which is composed of the following raw materials in parts by weight: 65 parts of fluorosilicone rubber, 35 parts of hydrogenated nitrile rubber, 6 parts of modified graphene nanosheets, 4 parts of plasticizer, 12 parts of halogen-free flame retardant, 3 parts of self-healing microcapsules, 2 parts of cross-linking agent and 2.5 parts of calcium carbonate; The preparation method of modified graphene nanosheets includes: vacuum drying graphene oxide at 85°C for 11 hours, dispersing the dried graphene oxide in acetone, and ultrasonically treating at 40kHz for 35 minutes to form a uniform dispersion; slowly adding toluene diisocyanate to the dispersion at 27°C under nitrogen protection; continuously stirring at 950rpm, and reacting for 22 hours under 35kHz ultrasonic assistance to form hydrophobic modified graphene; after the reaction, adding ethanol to precipitate the product, and the weight ratio of graphene oxide, acetone, toluene diisocyanate and ethanol is 1:30:50:130; after filtering, washing with ethanol three times, and vacuum drying at 55°C for 11 hours to obtain modified graphene nanosheets; The preparation method of the self-healing microcapsule includes: mixing a silane coupling agent KH-550 and a catalyst dibutyltin dilaurate in a weight ratio of 0.5:100 to obtain a core material; mixing hexamethylene diisocyanate and polyether polyol in a molar ratio of 1:2.5 to obtain a shell material; dispersing the silane coupling agent core material in a mixed solution of ethanol and water containing an emulsifier Span-80, stirring at a high speed to form an emulsion, slowly adding a polyurethane shell material solution dissolved in ethyl acetate, reacting at 55°C for 3.5 hours, filtering the microcapsule suspension after the reaction, washing with deionized water for 3 times, and vacuum drying at 45°C to obtain a self-healing microcapsule with a particle size of 30 μm; the weight ratio of the silane coupling agent core material, the emulsifier Span-80, ethanol, and water is 10:1:90:10; the weight ratio of the shell material and ethyl acetate in the polyurethane shell material solution of ethyl acetate is 1:4.5; the weight ratio of the emulsion and the polyurethane shell material solution is 5:1; The plasticizer is epoxy triglyceride; the halogen-free flame retardant is Exolit OP1312, purchased from Clariant Specialty Chemicals; the crosslinker is bisphenol AF; The preparation method of the rubber material for the rubber sealing ring comprises the following steps: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 130°C and a rotation speed of 250rpm; adding modified graphene nanosheets and calcium carbonate, and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer, halogen-free flame retardant, and self-repairing microcapsules into an internal mixer and mixing for 12 minutes at a temperature of 85°C; then vulcanizing for 9 minutes at a pressure of 12MPa and a temperature of 155°C, and then vulcanizing for 3.5 hours at 200°C to obtain the rubber material for the rubber sealing ring.

[0031] Comparative Example 4 In this comparative example, a rubber material for a rubber sealing ring is provided, which is composed of the following raw materials in parts by weight: 65 parts of fluorosilicone rubber, 35 parts of hydrogenated nitrile rubber, 6 parts of graphene nanosheets, 4 parts of plasticizer, 12 parts of halogen-free flame retardant, 3 parts of self-healing microcapsules, 2 parts of cross-linking agent and 2.5 parts of cerium oxide; The preparation method of the self-healing microcapsule includes: mixing a silane coupling agent KH-550 and a catalyst dibutyltin dilaurate in a weight ratio of 0.5:100 to obtain a core material; mixing hexamethylene diisocyanate and polyether polyol in a molar ratio of 1:2.5 to obtain a shell material; dispersing the silane coupling agent core material in a mixed solution of ethanol and water containing an emulsifier Span-80, stirring at a high speed to form an emulsion, slowly adding a polyurethane shell material solution dissolved in ethyl acetate, reacting at 55°C for 3.5 hours, filtering the microcapsule suspension after the reaction, washing with deionized water for 3 times, and vacuum drying at 45°C to obtain a self-healing microcapsule with a particle size of 30 μm; the weight ratio of the silane coupling agent core material, the emulsifier Span-80, ethanol, and water is 10:1:90:10; the weight ratio of the shell material and ethyl acetate in the polyurethane shell material solution of ethyl acetate is 1:4.5; the weight ratio of the emulsion and the polyurethane shell material solution is 5:1; The plasticizer is epoxy triglyceride; the halogen-free flame retardant is Exolit OP1312, purchased from Clariant Specialty Chemicals; the crosslinker is bisphenol AF; The preparation method of the rubber material for the rubber sealing ring comprises the following steps: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 130°C and a rotation speed of 250rpm; adding modified graphene nanosheets and cerium oxide, and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer, halogen-free flame retardant, and self-repairing microcapsules into an internal mixer and mixing for 12 minutes at a temperature of 85°C; then vulcanizing for 9 minutes at a pressure of 12MPa and a temperature of 155°C, and then vulcanizing for 3.5 hours at 200°C to obtain the rubber material for the rubber sealing ring.

[0032] Comparative Example 5 In this comparative example, a rubber material for a rubber sealing ring is provided, which is composed of the following raw materials in parts by weight: 65 parts of fluorosilicone rubber, 35 parts of hydrogenated nitrile rubber, 4 parts of plasticizer, 12 parts of halogen-free flame retardant, 2 parts of crosslinking agent and 2.5 parts of cerium oxide; The plasticizer is epoxy triglyceride; the halogen-free flame retardant is Clariant Exolit OP1312; the crosslinking agent is bisphenol AF; The preparation method of the rubber material for the rubber sealing ring comprises the following steps: extruding fluorosilicone rubber and hydrogenated nitrile rubber in a twin-screw extruder at a temperature of 130°C and a rotation speed of 250rpm; adding cerium oxide and obtaining a premix by ensuring uniform distribution through ultrasonic dispersion; adding the premix, plasticizer and halogen-free flame retardant into an internal mixer and mixing for 12 minutes at a temperature of 85°C; then vulcanizing for 9 minutes at a pressure of 12MPa and a temperature of 155°C, and then vulcanizing for 3.5 hours at 200°C to obtain the rubber material for the rubber sealing ring.

[0033] Test Example 1: The rubber materials for rubber sealing rings prepared in the above-mentioned Examples 1-4 and Comparative Examples 1-5 were tested as follows: 1. Hot air aging test: refer to ASTM D573 for testing, sample size: 25mm×25mm×2mm; condition: aging at 200℃ for 72 hours, and testing the tensile strength retention rate (%); the tensile strength testing method refers to ASTM D638 for measuring the tensile strength, using a universal material testing machine, and the tensile speed is 50mm / min; 2. Wear resistance: Refer to GB / T 1689-2014 Akron abrasion test to test the wear amount. The volume loss (cm2) of the sample after 40 meters of wear under a load of 1 kg 3 ); 3. Oil resistance test: refer to ASTM D471 for testing, medium: IRM903 standard oil, immerse at 70℃ for 48 hours, and detect the volume change rate (%).

[0034] The results are shown in Table 1 below: Table 1

[0035] According to the data, the tensile strength retention rates of Examples 1-4 are all higher than 85%. Thanks to the high thermal conductivity of the modified graphene and the dense network formed by dynamic vulcanization, the temperature resistance of Comparative Examples 1 and 4 is significantly reduced, indicating that the hydrophobicity and dispersibility of the modified graphene are the key.

[0036] The Akron wear loss in the examples is less than 0.21 cm³, which is attributed to the synergistic enhancement of modified graphene and cerium oxide. The wear resistance of comparative examples 3 and 4 decreases, indicating that the unique filling effect of cerium oxide and modified graphene is irreplaceable.

[0037] The volume change rates of the examples are all lower than +7.5%, indicating that the oil resistance of hydrogenated nitrile rubber plays a major role. The volume expansion rate of comparative example 5 is the highest, indicating that the modified graphene and the self-healing microcapsules jointly inhibit the penetration of the medium.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rubber material for a rubber sealing ring, characterized in that: The invention is composed of the following raw materials in parts by weight: 60-70 parts of fluorosilicone rubber, 30-40 parts of hydrogenated nitrile rubber, 5-8 parts of modified graphene nanosheets, 3-5 parts of plasticizer, 10-15 parts of halogen-free flame retardant, 2-4 parts of self-repairing microcapsules, 1.5-2.5 parts of crosslinking agent and 2-3 parts of cerium oxide.

2. The rubber material for a rubber sealing ring according to claim 1, characterized in that: The preparation method of the modified graphene nanosheet comprises: vacuum drying graphene oxide at 80-90° C. for 10-12 hours, dispersing the dried graphene oxide in acetone, and ultrasonically forming a uniform dispersion; slowly adding toluene diisocyanate to the dispersion at a temperature of 25-30° C. under nitrogen protection; continuously stirring at 900-1000 rpm, and reacting for 20-24 hours under the assistance of ultrasound to form hydrophobic modified graphene; after the reaction is completed, adding ethanol to precipitate the product, filtering, washing, and drying to obtain the modified graphene nanosheet.

3. The rubber material for a rubber sealing ring according to claim 2, characterized in that: The weight ratio of the graphene oxide, acetone, toluene diisocyanate and ethanol is 1:28-32:45-55:120-140.

4. The rubber material for a rubber sealing ring according to claim 1, characterized in that: The core material of the self-repairing microcapsule is a silane coupling agent, the shell material is polyurethane, and the particle size of the self-repairing microcapsule is 10-50 μm.

5. The rubber material for a rubber sealing ring according to claim 4, characterized in that: The preparation method of the self-repairing microcapsule comprises: dispersing a silane coupling agent core material in a mixed solution of ethanol and water containing an emulsifier, stirring at high speed to form an emulsion, adding a polyurethane shell material solution dissolved in ethyl acetate, reacting at 50-60° C. for 3-4 hours, filtering the microcapsule suspension after the reaction, washing with deionized water for 3 times, and vacuum drying at 40-50° C. to obtain a self-repairing microcapsule with a particle size of 10-50 μm.

6. The rubber material for a rubber sealing ring according to claim 5, characterized in that: The preparation method of the core material comprises: mixing a silane coupling agent KH-550 and a dibutyltin dilaurate catalyst in a weight ratio of 0.5:95-105 to obtain the core material.

7. The rubber material for a rubber sealing ring according to claim 5, characterized in that: The preparation method of the shell material comprises: mixing hexamethylene diisocyanate and polyether polyol in a molar ratio of 1:2-3 to obtain the shell material.

8. The rubber material for a rubber sealing ring according to claim 5, characterized in that: The weight ratio of the silane coupling agent core material, the emulsifier Span-80, ethanol and water is 9-11: 0.5-1.5:85-95:9-11; the weight ratio of the shell material to ethyl acetate in the polyurethane shell material solution of ethyl acetate is 1:4-5; the weight ratio of the emulsion to the polyurethane shell material solution is 4-6:

1.

9. The rubber material for a rubber sealing ring according to claim 1, characterized in that: The plasticizer is epoxy triglyceride; the model of the halogen-free flame retardant is Exolit OP1312; and the cross-linking agent is bisphenol AF.

10. The method for preparing the rubber material for the rubber sealing ring according to any one of claims 1 to 9, characterized in that the steps include: The fluorosilicone rubber and hydrogenated nitrile rubber are extruded in a twin-screw extruder at a temperature of 120-140°C and a rotation speed of 200-300 rpm; Modified graphene nanosheets and cerium oxide are added, and uniform distribution is ensured by ultrasonic dispersion to obtain a premix; the premix, plasticizer, halogen-free flame retardant and self-healing microcapsule are added to an internal mixer and kneaded for 10-15 minutes at a temperature of 80-90°C; then, the mixture is first vulcanized at a pressure of 10-15MPa and a temperature of 150-160°C for 8-10 minutes, and then vulcanized at 190-210°C for 3-4 hours to obtain the mixture.

Images