A high temperature resistant and corrosion resistant silicone rubber sealing ring and preparation method thereof

Abstract

The invention discloses a high-temperature resistant and corrosion-resistant silicone rubber sealing ring and a preparation method thereof, belonging to the technical field of new materials. The invention comprises the following raw material compositions in parts by weight: 80-100 parts of hybrid fluorosilicone rubber, 15-20 parts of hollow fillers, 0.5-2 parts of vulcanizers, 5-10 parts of plasticizers, 3-5 parts of heat stabilizers and 0.5-1 parts of organosilicon defoamers; the invention introduces silicon hydrogen groups and double bond structures into modified fluorosilicone resin, which are cross-linked with monomer structures and reinforcing fillers to form complex cyclic, cross-linked and grafted structures, and finally significantly improve the segment complexity of the hybrid fluorosilicone resin and introduce a large number of fluorine groups, and after being mixed with hollow fillers and auxiliary materials for vulcanization, a wear-resistant, tensile-resistant and high-temperature resistant corrosion-resistant silicone rubber sealing ring is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of new materials, and in particular to a high-temperature resistant and corrosion-resistant silicone rubber sealing ring and a preparation method thereof. Background Art

[0002] The development of silicone rubber seals began in the mid-20th century, when scientists sought a material with excellent temperature and corrosion resistance to meet the stringent needs of the aviation and aerospace industries. Silicone rubber quickly became a research focus with its unique thermal and chemical stability. Since then, the formulation and manufacturing technology of silicone rubber has undergone significant evolution, especially in the use of fillers and additives. These improvements enhance its physical properties and durability. Today, silicone rubber seals are widely used in industries such as automobiles, medical equipment, and electronics. Their production technology is constantly innovating to meet the requirements of various extreme environments. Through continuous material and process innovation, silicone rubber seals are becoming more and more capable of providing efficient sealing solutions.

[0003] Prior art CN111205651A discloses a method for preparing a high-temperature resistant silicone rubber sealing ring, which comprises adding aluminum silicate fiber, mica powder and calcium carbonate powder into the raw materials of the silicone rubber sealing ring, wherein the calcium carbonate decomposes into calcium oxide and carbon dioxide at high temperature, absorbs a large amount of heat during the decomposition process, and increases the heat required for polymer decomposition, and the silicon dioxide decomposed by the silicone rubber at high temperature reacts with the mica powder and calcium oxide to form a ceramic product, which greatly improves the flame retardant properties, anti-drip properties and ceramic properties of the silicone rubber, and the carbon dioxide released by the decomposition of calcium carbonate can take away part of the heat energy, and the release of carbon dioxide occurs synchronously with ceramicization, thereby preventing the polymer from cracking during the ceramicization process.

[0004] However, the above patent content is to improve the high temperature resistance of the material by introducing high temperature decomposition of calcium carbonate to produce gas and calcium oxide, absorb a large amount of heat, but the high temperature decomposition of calcium carbonate will cause the structure of the material itself to be destroyed, affecting the physical properties of the material itself such as tensile strength, resulting in the high temperature anti-aging performance of the material needs to be further improved, and the structural damage will cause corrosive substances to further invade the interior of the sealing ring, thereby reducing the corrosion resistance of the material.

[0005] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a high temperature resistant and corrosion resistant silicone rubber sealing ring and a preparation method thereof, so as to solve the technical problem that the high temperature resistance and corrosion resistance of the silicone rubber sealing ring in the prior art need to be further improved.

[0007] The purpose of the present invention can be achieved by the following technical scheme: a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following raw material composition in parts by weight: 80-100 parts of hybrid fluorosilicone rubber, 15-20 parts of hollow filler, 0.5-2 parts of vulcanizing agent, 5-10 parts of plasticizer, 3-5 parts of heat stabilizer and 0.5-1 parts of organosilicon defoaming agent;

[0008] The preparation method of hybrid fluorosilicone rubber comprises the following steps:

[0009] A1. Add modified fluorosilicone rubber and tetrahydrofuran into a reaction kettle, stir at room temperature for 10-15 minutes, add 3,5-bis(trifluoromethyl)phenyldimethylsilane into the reaction kettle, continue stirring for 3-5 minutes, and obtain a reaction precursor solution;

[0010] A2. Add the reaction precursor liquid into the reactor. After the temperature of the reactor is raised to 40-60°C, add dihydrogen platinum and reinforcing filler into the reactor. Keep the temperature for 1-2 hours and perform post-treatment to obtain hybrid fluorosilicone rubber.

[0011] The reaction principle for preparing hybrid fluorosilicone rubber is as follows: under the catalysis of platinum dihydride, the silicon-hydrogen bonds on the modified fluorosilicone resin and 3,5-bis(trifluoromethyl)phenyldimethylsilane and the double bonds inside the modified fluorosilicone resin and on the surface of the reinforcing filler undergo a silicon-hydrogen addition reaction, thereby obtaining a cyclic, cross-linked and grafted spatial hybrid structure, and finally obtaining a hybrid fluorosilicone resin.

[0012] Furthermore, in step A1, the stirring rate of the reactor is 80-120rpm, and the amount ratio of modified fluorosilicone rubber, tetrahydrofuran, and 3,5-bis(trifluoromethyl)phenyldimethylsilane is 8-10g:60-80mL:2-3g; in step A2, the amount ratio of reaction precursor liquid and dihydrogen platinum is 60-80mL:0.3-0.5g:2-3g, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is lowered to room temperature, 2-3 times the volume of the reaction precursor liquid is added to the reactor. Anhydrous ethanol is added, flocculation is performed for 20-30min, the reaction liquid is filtered, the filter cake is collected, and the filter cake is dissolved in tetrahydrofuran solution again. After repeating the flocculation and filtration for 3-5 times, the filtered precipitate is placed in a drying oven at a temperature of 60-80°C, and vacuum dried until the precipitate has a constant weight to obtain a hybrid fluorosilicone rubber.

[0013] Furthermore, the vulcanizing agent is one or more of dibenzoyl peroxide, thiuram disulfide and thiophenol dicarboxaldehyde; the plasticizer is one or more of dibutyl phthalate, dioctyl phthalate and dioctyl terephthalate; and the heat stabilizer is one or more of lead stearate, tribasic lead sulfate and epoxidized soybean oil.

[0014] Furthermore, the preparation method of the modified fluorosilicone rubber comprises the following steps:

[0015] B1, adding 2,4,6,8-tetramethylcyclotetrasiloxane, tetramethyldivinyldisiloxane and tetrahydrofuran into a reaction kettle, stirring at room temperature for 15-20 minutes to obtain a prepolymer solution;

[0016] B2. Add the prepolymer liquid and the catalyst into the reactor, raise the temperature of the reactor to 40-60°C, keep the reaction warm for 2-3 hours, add the modified end-capping agent into the reactor, continue to keep the reaction warm for 40-60 minutes, add 5-8wt% ammonia solution into the reactor containing the reaction liquid until the pH value of the reaction liquid is 7-8, and obtain the modified fluorosilicone rubber by post-treatment.

[0017] The reaction equation for preparing modified fluorosilicone rubber is:

[0018]

[0019] Wherein: “*” represents the active connection site of the organic chain segment.

[0020] The reaction principle for preparing modified fluorosilicone rubber is as follows: under the catalysis of sulfuric acid and heating, the cyclic siloxane structure is hydrolyzed and cross-linked to produce a segment structure, which is finally capped by a modified capping agent to obtain a long segment structure, and finally the modified fluorosilicone rubber is prepared.

[0021] Furthermore, in step B1, the stirring rate of the reactor is 60-80rpm, and the amount ratio of 2,4,6,8-tetramethylcyclotetrasiloxane, tetramethyldivinyldisiloxane and tetrahydrofuran is 6-8g:8-10g:80-100mL; in step B2, the amount ratio of the prepolymer liquid, the catalyst and the modified end-capping agent is 40-50mL:5-6mL:4-6g, and the catalyst is a 60-80wt% sulfuric acid solution. The post-treatment includes: after the reaction is completed, the temperature of the reactor is lowered to room temperature, 2-3 times the volume of the prepolymer liquid is added to the reactor. Anhydrous ethanol, flocculation for 20-30min, the reaction liquid is filtered, the filter cake is collected, and the filter cake is dissolved in tetrahydrofuran solution again. After repeating the flocculation and filtration for 3-5 times, the filtered precipitate is placed in a drying oven at a temperature of 60-80°C, and vacuum dried until the precipitate is constant weight to obtain a hybrid fluorosilicone rubber.

[0022] Furthermore, the preparation method of the modified end-capping agent is as follows: trivinylethoxysilane and N,N-dimethylformamide are added to a reactor, stirred at room temperature for 10-15 minutes, benzoin dimethyl ether and 1H,1H,2H,2H-perfluorodecyl mercaptan are added to the reactor, and irradiated with an ultraviolet lamp for 30-40 minutes to obtain the modified end-capping agent.

[0023] The reaction equation for preparing the modified end-capping agent is:

[0024]

[0025] Where: Rn is R 1-2 , where R1: “*” indicates the active linking site of the organic chain segment.

[0026] The reaction principle for preparing the modified end-capping agent is as follows: under the initiation of ultraviolet rays, the catalyst benzoin dimethyl ether decomposes to generate free radicals that react with the hydrogen groups on the thiol, so that 1H, 1H, 2H, 2H-perfluorodecyl mercaptan generates free radicals, which further react with the olefin structure on the trivinylethoxysilane to finally prepare the modified end-capping agent.

[0027] Furthermore, the dosage ratio of trivinylethoxysilane, N,N-dimethylformamide, benzoin dimethyl ether and 1H,1H,2H,2H-perfluorodecyl mercaptan is 3-5g:20-30mL:0.3-0.5g:4-6g, the wavelength of the ultraviolet lamp is 350-370nm, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction solution is transferred to a rotary evaporator at a temperature of 80-90°C, and the solvent is evaporated under reduced pressure to obtain a modified capping agent.

[0028] Furthermore, the preparation method of the reinforcing filler comprises the following steps:

[0029] C1. Add hollow glass balls and 3-4 wt% sodium hydroxide aqueous solution into a reaction kettle and stir. Raise the temperature of the reaction kettle to 50-60° C., keep the temperature for 1-2 hours, and perform post-treatment to obtain activated microspheres.

[0030] C2, adding activated microspheres, aluminum chloride and anhydrous ethanol into a reactor and stirring, stirring at room temperature for 15-20 minutes, and then continuing to drop deionized water, after the temperature of the reactor is raised to 40-60°C, using 1-1.5 mol / L ammonia solution to adjust the system pH to 8-9, and heat preservation for 24-36 hours to obtain a mixed gel, and post-processing to obtain a composite filler;

[0031] C3, adding the composite filler and 1-2 mol / L sodium hydroxide solution into a reactor, ultrasonicating for 3-5 hours at room temperature, and post-treating to obtain a hollow filler;

[0032] C4. Add hollow filler, 5-hexenyltrimethoxysilane, sodium hydroxide and deionized water into the reactor, increase the temperature of the reactor to 30-50°C, keep the temperature for 3-5h, and post-treat to obtain the reinforced filler.

[0033] The reaction principle for preparing reinforcing fillers is as follows: after hollow glass balls are corroded by a low-concentration sodium hydroxide aqueous solution, a large number of highly active hydroxyl structures appear on the surface. During the hydrolysis process, aluminum chloride uses the hydroxyl groups on the surface of the activated microspheres as cross-linking base points, and eventually forms a stable gel structure. Composite fillers are obtained after calcination and grinding. After corrosion by a high-concentration sodium hydroxide solution and ultrasonic removal, hollow fillers with porous hollow structures are finally formed. Finally, under alkaline conditions, the surface of the hollow filler is modified by a silane coupling agent to obtain a reinforcing filler.

[0034] Further, in step C1, the stirring rate of the reactor is 80-120 rpm, the amount ratio of the hollow glass balls to the 3-4 wt% sodium hydroxide aqueous solution is 1-2 g: 10-15 mL, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is lowered to room temperature, the filter cake is collected by suction filtration, and the filter cake is transferred to a drying oven at a temperature of 60-80° C. and vacuum dried until the filter cake has a constant weight, thereby obtaining activated microspheres;

[0035] In step C2, the stirring rate of the reactor is 60-80rpm, the amount ratio of activated microspheres, aluminum chloride, anhydrous ethanol and deionized water is 1-2g:5-8g:30-40mL:10-20mL, and the post-treatment includes: adding the mixed gel into a tubular furnace, after nitrogen protection, heating the tubular furnace to 750-850°C at a heating rate of 3-5°C / min, calcining for 4-6h, and grinding the material through a 600-800 mesh screen to obtain a composite filler;

[0036] In step C3, the ratio of the composite filler to the 1-2 mol / L sodium hydroxide solution is 1 g: 20-30 mL, the ultrasonic frequency is 20-40 kHz, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is lowered to room temperature, the filter cake is collected by suction filtration, and the filter cake is transferred to a drying oven at a temperature of 60-80° C. and vacuum dried until the filter cake has a constant weight, thereby obtaining a hollow filler;

[0037] In step C4, the usage ratio of hollow filler, 5-hexenyltrimethoxysilane, sodium hydroxide and deionized water is 8-10g:2-3g:0.8-1g:30-50mL, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is lowered to room temperature, the filter cake is collected by suction filtration, and the filter cake is transferred to a drying oven at a temperature of 60-80°C and vacuum dried until the filter cake has a constant weight to obtain a reinforcing filler.

[0038] The present invention also provides a method for preparing a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0039] S1. Mix the hybrid fluorosilicone rubber, hollow filler, vulcanizer, plasticizer, heat stabilizer and organosilicon defoamer and add them into an internal mixer. The internal mixing temperature is 120-140°C for 20-40 minutes. After the internal mixing is completed, discharge the material and cool for 4-5 hours to obtain a rubber compound.

[0040] S2, putting the rubber material into an injection molding machine, the barrel temperature of the injection molding machine is 200-220°C, the nozzle temperature is 190-240°C, and injection molding is performed to obtain a silicone rubber sealing ring precursor;

[0041] S3. Put the silicone rubber sealing ring precursor into a flat vulcanizer and vulcanize it for 25-35 minutes to obtain a silicone rubber sealing ring.

[0042] Furthermore, in step S3, the temperature of the flat plate vulcanizer is 130-150° C. and the pressure is 0.35-0.50 MPa.

[0043] The present invention has the following beneficial effects:

[0044] 1. The present invention introduces silicon hydrogen groups and double bond structures into the modified fluorosilicone resin, which form complex cyclic, cross-linked and grafted structures by cross-linking with the monomer structure and reinforcing fillers, thereby improving the segment complexity of the hybrid fluorosilicone resin and introducing a large number of fluorine groups, thereby improving the corrosion resistance, tensile strength and wear resistance of the hybrid fluorosilicone resin. After being mixed with hollow fillers and auxiliary materials and vulcanized, the hollow fillers are evenly dispersed inside the sealing ring, and the spherical porous structure makes it have extremely excellent high-temperature stability, and the structure and properties will not change at high temperatures, thereby supporting the sealing ring structure, significantly improving the high-temperature resistance of the material, and obtaining a wear-resistant, tensile-resistant and high-temperature resistant corrosion-resistant silicone rubber sealing ring.

[0045] 2. In the process of preparing reinforcing fillers of the present invention, the surfaces of the activated microspheres obtained after activation have a large number of active functional group hydroxyls, which serve as supporting materials in the process of preparing a gel-like structure by hydrolysis of aluminum chloride and preparing a composite filler by calcination, so that the hollow filler has a stable spherical porous structure. The spherical porous structure has a higher specific surface area, thereby providing more surface for heat exchange, thereby more effectively dissipating heat, so that the silicone rubber sealing ring can better withstand thermal stress, thereby improving the high temperature resistance of the material.

[0046] 3. In the process of preparing the modified end-capping agent, the present invention controls the dosage ratio of the drug when introducing the perfluoro group by photoinitiation on trivinylethoxysilane, so that the modified end-capping agent introduces a large number of fluorine groups and olefin structures at the end of the modified fluorosilicone resin segment during the end-capping process. In the process of preparing the hybrid fluorosilicone resin, it is coordinated with 3,5-bis(trifluoromethyl)phenyldimethylsilane through silylation, thereby significantly improving the corrosion resistance of the material; by using 2,4,6,8-tetramethylcyclotetrasiloxane to introduce highly active silicon-hydrogen bonds into the modified fluorosilicone resin, in the process of preparing the hybrid fluorosilicone resin, the silicon-hydrogen bonds are cross-linked inside the segment, end-capping and reinforcing fillers under the catalysis of the catalyst to form complex cyclic, cross-linked and grafted structures, ultimately significantly improving the segment complexity of the hybrid fluorosilicone resin, and ultimately significantly improving the tensile strength and wear resistance of the silicone rubber sealing ring. DETAILED DESCRIPTION

[0047] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than 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.

[0048] The organosilicon defoamer used in the present invention is purchased from Shandong Kasong Chemical Co., Ltd., with the item number KS-3130.

[0049] Example 1

[0050] This embodiment provides a method for preparing a reinforcing filler for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0051] Step I: Preparation of activated microspheres

[0052] Weigh: 100.0g hollow glass balls and 1.0L 3wt% sodium hydroxide aqueous solution are added to the reactor and stirred at a stirring rate of 80rpm. The temperature of the reactor is raised to 50°C and the reaction is kept warm for 1h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction is filtered and the filter cake is collected. The filter cake is transferred to a drying oven at a temperature of 60°C and vacuum dried until the filter cake has a constant weight to obtain activated microspheres.

[0053] Step II: Preparation of composite filler

[0054] Weigh: 100.0g activated microspheres, 500.0g aluminum chloride and 3.0L anhydrous ethanol are added to a reactor and stirred at a stirring rate of 60rpm. After stirring at room temperature for 15min, 1.0L deionized water is continued to be added dropwise. After the temperature of the reactor is raised to 40°C, a 1.0mol / L ammonia solution is used to adjust the pH of the system to 8. The mixture is kept warm for 24h to obtain a mixed gel. The mixed gel is added to a tubular furnace. After nitrogen protection is introduced, the tubular furnace is heated to 750°C at a heating rate of 3°C / min. After calcination for 4h, the material is ground through a 600-mesh sieve to obtain a composite filler.

[0055] Step III: Preparation of hollow filler

[0056] Weigh: 100.0g of composite filler and 2.0L of 1mol / L sodium hydroxide solution are added to a reactor for ultrasonication at an ultrasonic frequency of 20kHz for 3 hours at room temperature. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the filter cake is collected by suction filtration, and the filter cake is transferred to a drying oven at a temperature of 60°C and vacuum dried until the filter cake has a constant weight to obtain a hollow filler.

[0057] Step IV: Preparation of reinforcing filler

[0058] Weigh: 800.0g hollow filler, 200.0g 5-hexenyltrimethoxysilane, 80.0g sodium hydroxide and 3.0L deionized water, add into the reactor, raise the temperature of the reactor to 30°C, and keep warm for 3h. After the reaction is completed, lower the temperature of the reactor to room temperature, filter the reaction and collect the filter cake, transfer the filter cake to a drying oven at 60°C and vacuum dry it until the filter cake has constant weight to obtain a reinforcing filler.

[0059] Example 2

[0060] This embodiment provides a method for preparing a reinforcing filler for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0061] Step I: Preparation of activated microspheres

[0062] Weigh: 200.0g hollow glass balls and 1.5L 4wt% sodium hydroxide aqueous solution are added to the reactor and stirred at a stirring rate of 120rpm. The temperature of the reactor is raised to 60°C and kept warm for 2h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the filter cake is collected by suction filtration, and the filter cake is transferred to a drying oven at a temperature of 80°C and vacuum dried until the filter cake has a constant weight to obtain activated microspheres.

[0063] Step II: Preparation of composite filler

[0064] Weigh: 200.0g activated microspheres, 800.0g aluminum chloride and 4.0L anhydrous ethanol are added to the reactor and stirred at a stirring rate of 80rpm. After stirring at room temperature for 20min, 2.0L deionized water is continued to be added dropwise. After the temperature of the reactor is raised to 60°C, 1.5mol / L ammonia solution is used to adjust the pH of the system to 9. The mixture is kept warm for 36h to obtain a mixed gel. The mixed gel is added to a tubular furnace. After nitrogen protection is introduced, the tubular furnace is heated to 850°C at a heating rate of 5°C / min. After calcination for 6h, the material is ground through an 800-mesh sieve to obtain a composite filler.

[0065] Step III: Preparation of hollow filler

[0066] Weigh: 100.0g of composite filler and 3.0L of 2mol / L sodium hydroxide solution are added to a reactor for ultrasonication at an ultrasonic frequency of 40kHz for 5 hours at room temperature. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the filter cake is collected by suction filtration, and the filter cake is transferred to a drying oven at a temperature of 80°C and vacuum dried until the filter cake has a constant weight to obtain a hollow filler.

[0067] Step IV: Preparation of reinforcing filler

[0068] Weigh: 1000.0g hollow filler, 300.0g 5-hexenyltrimethoxysilane, 100.0g sodium hydroxide and 5.0L deionized water, add into the reactor, raise the temperature of the reactor to 50°C, and keep warm for 5h. After the reaction is completed, lower the temperature of the reactor to room temperature, filter the reaction and collect the filter cake, transfer the filter cake to a drying oven at 80°C and vacuum dry it until the filter cake has constant weight to obtain a reinforcing filler.

[0069] Example 3

[0070] This embodiment provides a method for preparing a reinforcing filler for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0071] Step I: Preparation of activated microspheres

[0072] Weigh: 150.0g hollow glass balls and 1.2L 4wt% sodium hydroxide aqueous solution are added to the reactor and stirred at a stirring rate of 120rpm. The temperature of the reactor is raised to 60°C and kept warm for 2h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the filter cake is collected by suction filtration, and the filter cake is transferred to a drying oven at a temperature of 70°C and vacuum dried until the filter cake has a constant weight to obtain activated microspheres.

[0073] Step II: Preparation of composite filler

[0074] Weigh: 150.0g activated microspheres, 650.0g aluminum chloride and 3.5L anhydrous ethanol are added to the reactor and stirred at a stirring rate of 70rpm. After stirring at room temperature for 18min, 1.5L deionized water is continued to be added dropwise. After the temperature of the reactor is raised to 50°C, 1.2mol / L ammonia solution is used to adjust the pH of the system to 9, and the mixture is kept warm for 30h to obtain a mixed gel. The mixed gel is added to a tubular furnace, and after nitrogen protection is introduced, the tubular furnace is heated to 800°C at a heating rate of 5°C / min. After calcination for 5h, the material is ground through a 700-mesh sieve to obtain a composite filler.

[0075] Step III: Preparation of hollow filler

[0076] Weigh: 100.0g of composite filler and 2.5mL of 1.5mol / L sodium hydroxide solution are added to a reactor for ultrasonication at a frequency of 30kHz for 4 hours at room temperature. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the filter cake is collected by suction filtration, and the filter cake is transferred to a drying oven at a temperature of 70°C and vacuum dried until the filter cake has a constant weight to obtain a hollow filler.

[0077] Step IV: Preparation of reinforcing filler

[0078] Weigh: 900.0g hollow filler, 250.0g 5-hexenyltrimethoxysilane, 90.0g sodium hydroxide and 4.0L deionized water, add into the reactor, raise the temperature of the reactor to 40°C, and keep warm for 4h. After the reaction is completed, lower the temperature of the reactor to room temperature, filter the reaction and collect the filter cake, transfer the filter cake to a drying oven at 70°C and vacuum dry it until the filter cake has constant weight to obtain a reinforcing filler.

[0079] Example 4

[0080] This embodiment provides a method for preparing a modified fluorosilicone rubber for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0081] Step ①: Preparation of modified end-capping agent

[0082] Weigh: 300.0g of trivinylethoxysilane and 2.0LN,N-dimethylformamide are added to a reactor, stirred at room temperature for 10 minutes, then 30.0g of benzoin dimethyl ether and 400.0g of 1H,1H,2H,2H-perfluorodecyl mercaptan are added to the reactor, and irradiated with an ultraviolet lamp for 30 minutes, the wavelength of the ultraviolet lamp is 350nm. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction solution is transferred to a rotary evaporator at a temperature of 80°C, and the solvent is evaporated under reduced pressure to obtain a modified end-capping agent.

[0083] Step ②: Preparation of prepolymer solution

[0084] Weigh 600.0 g of 2,4,6,8-tetramethylcyclotetrasiloxane, 800.0 g of tetramethyldivinyldisiloxane and 8.0 L of tetrahydrofuran into a reaction kettle, stir at a rate of 60 rpm, and stir at room temperature for 15 min to obtain a prepolymer solution.

[0085] Step ③: Preparation of modified fluorosilicone rubber

[0086] Weigh: 4.0L prepolymer solution and 500.0mL 60wt% sulfuric acid solution are added to the reactor, the temperature of the reactor is raised to 40°C, and the reaction is kept warm for 2h. Then, 400.0g of end-capping agent is added to the reactor, and the reaction is kept warm for 40min. A 5wt% ammonia solution is added to the reactor containing the reaction liquid until the pH of the reaction liquid reaches 7. After the reaction is completed, the temperature of the reactor is lowered to room temperature, 8.0L of anhydrous ethanol is added to the reactor, flocculation is performed for 20min, the reaction liquid is filtered, the filter cake is collected, and the filter cake is dissolved in tetrahydrofuran solution again. After repeating the flocculation and filtration for 3 times, the filtered precipitate is placed in a drying oven at 60°C, and vacuum dried until the precipitate has a constant weight to obtain a hybrid fluorosilicone rubber.

[0087] Example 5

[0088] This embodiment provides a method for preparing a modified fluorosilicone rubber for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0089] Step ①: Preparation of modified end-capping agent

[0090] Weigh: 500.0g of trivinylethoxysilane and 3.0LN,N-dimethylformamide are added to a reactor, stirred at room temperature for 15 minutes, then 50.0g of benzoin dimethyl ether and 600.0g of 1H,1H,2H,2H-perfluorodecyl mercaptan are added to the reactor, and irradiated with an ultraviolet lamp for 40 minutes, the wavelength of the ultraviolet lamp is 370nm. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction solution is transferred to a rotary evaporator at a temperature of 90°C, and the solvent is evaporated under reduced pressure to obtain a modified end-capping agent.

[0091] Step ②: Preparation of prepolymer solution

[0092] Weigh 800.0 g of 2,4,6,8-tetramethylcyclotetrasiloxane, 1000.0 g of tetramethyldivinyldisiloxane and 10.0 L of tetrahydrofuran into a reaction kettle, stir at a rate of 80 rpm, and stir at room temperature for 20 min to obtain a prepolymer solution.

[0093] Step ③: Preparation of modified fluorosilicone rubber

[0094] Weigh: 5.0L prepolymer solution and 600mL 80wt% sulfuric acid solution are added to the reactor, the temperature of the reactor is raised to 60°C, and the reaction is kept warm for 3h. Then, 600.0g of end-capping agent is added to the reactor, and the reaction is kept warm for 60min. 8wt% ammonia solution is added to the reactor containing the reaction liquid until the pH of the reaction liquid reaches 8. After the reaction is completed, the temperature of the reactor is lowered to room temperature, 10.0L of anhydrous ethanol is added to the reactor, flocculation is performed for 30min, the reaction liquid is filtered, the filter cake is collected, and the filter cake is dissolved in tetrahydrofuran solution again. After repeating the flocculation and filtration for 5 times, the filtered precipitate is placed in a drying oven at 80°C, and vacuum dried until the precipitate has a constant weight to obtain a hybrid fluorosilicone rubber.

[0095] Example 6

[0096] This embodiment provides a method for preparing a modified fluorosilicone rubber for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0097] Step ①: Preparation of modified end-capping agent

[0098] Weigh: 400.0g of trivinylethoxysilane and 2.5LN,N-dimethylformamide are added to a reactor, stirred at room temperature for 15 minutes, then 40.0g of benzoin dimethyl ether and 500.0g of 1H,1H,2H,2H-perfluorodecyl mercaptan are added to the reactor, and irradiated with an ultraviolet lamp for 35 minutes, the wavelength of the ultraviolet lamp is 365nm. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction solution is transferred to a rotary evaporator at a temperature of 85°C, and the solvent is evaporated under reduced pressure to obtain a modified end-capping agent.

[0099] Step ②: Preparation of prepolymer solution

[0100] Weigh 700.0 g of 2,4,6,8-tetramethylcyclotetrasiloxane, 900.0 g of tetramethyldivinyldisiloxane and 9.0 L of tetrahydrofuran into a reaction kettle, stir at a rate of 70 rpm, and stir at room temperature for 18 min to obtain a prepolymer solution.

[0101] Step ③: Preparation of modified fluorosilicone rubber

[0102] Weigh: 4.5L prepolymer solution and 550.0mL 70wt% sulfuric acid solution are added to the reactor, the temperature of the reactor is raised to 50°C, and the reaction is kept warm for 3h. Then, 500.0g of end-capping agent is added to the reactor, and the reaction is kept warm for 50min. A 6wt% ammonia solution is added to the reactor containing the reaction liquid until the pH of the reaction liquid reaches 8. After the reaction is completed, the temperature of the reactor is lowered to room temperature, 9.0L of anhydrous ethanol is added to the reactor, flocculated for 25min, the reaction liquid is filtered, the filter cake is collected, and the filter cake is dissolved in tetrahydrofuran solution again. After repeating the flocculation and filtration 4 times, the filtered precipitate is placed in a drying oven at 70°C, and vacuum dried until the precipitate has a constant weight to obtain a hybrid fluorosilicone rubber.

[0103] Example 7

[0104] This embodiment provides a method for preparing a hybrid fluorosilicone rubber for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0105] Step (1): preparing reaction precursor solution

[0106] Weigh: 800.0 g of modified fluorosilicone rubber prepared in Example 4 and 6.0 L of tetrahydrofuran were added to the reactor at a stirring rate of 80 rpm. After stirring at room temperature for 10 min, 200.0 g of 3,5-bis(trifluoromethyl)phenyldimethylsilane was added to the reactor. After continuing to stir for 3 min, a reaction precursor solution was obtained.

[0107] Step (2): Preparation of hybrid fluorosilicone rubber

[0108] Weigh: 6.0L of reaction precursor liquid is added to the reactor. After the temperature of the reactor is raised to 40°C, 30.0g of dihydrogen platinum and 200.0g of the reinforcing filler prepared in Example 1 are added to the reactor. The reaction is kept warm for 1h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, 12.0L of anhydrous ethanol is added to the reactor, flocculation is performed for 20min, the reaction liquid is filtered, the filter cake is collected, and the filter cake is dissolved in tetrahydrofuran solution again. After repeating the flocculation and filtration for 3 times, the filtered precipitate is placed in a drying oven at a temperature of 40°C, and vacuum dried until the precipitate has a constant weight to obtain a hybrid fluorosilicone rubber.

[0109] Example 8

[0110] This embodiment provides a method for preparing a hybrid fluorosilicone rubber for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0111] Step (1): preparing reaction precursor solution

[0112] Weigh: 1000.0 g of the modified fluorosilicone rubber prepared in Example 5 and 8.0 L of tetrahydrofuran were added to the reactor at a stirring rate of 120 rpm. After stirring at room temperature for 15 min, 300.0 g of 3,5-bis(trifluoromethyl)phenyldimethylsilane was added to the reactor. After continuing to stir for 5 min, a reaction precursor solution was obtained.

[0113] Step (2): Preparation of hybrid fluorosilicone rubber

[0114] Weigh: 8.0L of reaction precursor liquid is added to the reactor. After the temperature of the reactor is raised to 60°C, 50.0g of dihydrogen platinum and 300.0g of the reinforcing filler prepared in Example 2 are added to the reactor. The reaction is kept warm for 2h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, 16.0L of anhydrous ethanol is added to the reactor, flocculation is performed for 30min, the reaction liquid is filtered, the filter cake is collected, and the filter cake is dissolved in tetrahydrofuran solution again. After repeating the flocculation and filtration for 5 times, the filtered precipitate is placed in a drying oven at a temperature of 80°C, and vacuum dried until the precipitate has a constant weight to obtain a hybrid fluorosilicone rubber.

[0115] Example 9

[0116] This embodiment provides a method for preparing a hybrid fluorosilicone rubber for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0117] Step (1): preparing reaction precursor solution

[0118] Weigh: 1000.0 g of the modified fluorosilicone rubber prepared in Example 6 and 8.0 L of tetrahydrofuran were added to the reactor at a stirring rate of 120.0 rpm. After stirring at room temperature for 15 min, 250.0 g of 3,5-bis(trifluoromethyl)phenyldimethylsilane was added to the reactor. After continuing to stir for 4 min, a reaction precursor solution was obtained.

[0119] Step (2): Preparation of hybrid fluorosilicone rubber

[0120] Weigh: 7.0L of reaction precursor liquid is added to the reactor. After the temperature of the reactor is raised to 50°C, 40.0g of dihydrogen platinum and 250.0g of the reinforcing filler prepared in Example 3 are added to the reactor. The reaction is kept warm for 2h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, 14.0L of anhydrous ethanol is added to the reactor, flocculation is carried out for 25min, the reaction liquid is filtered, the filter cake is collected, and the filter cake is dissolved in tetrahydrofuran solution again. After repeating the flocculation and filtration 4 times, the filtered precipitate is placed in a drying oven at a temperature of 70°C, and vacuum dried until the precipitate has a constant weight to obtain a hybrid fluorosilicone rubber.

[0121] Example 10

[0122] This embodiment provides a method for preparing a hybrid fluorosilicone rubber for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0123] Step 1: Prepare the rubber compound

[0124] Weigh: 8.0 kg of hybrid fluorosilicone rubber prepared in Example 7, 1.5 kg of hollow filler prepared in Example 4, 50.0 g of dibenzoyl peroxide, 500.0 g of dibutyl phthalate, 300.0 g of epoxy soybean oil and 50.0 g of silicone defoamer, mix and add into an internal mixer. The internal mixing temperature is 120° C. and the time is 20 min. After the internal mixing is completed, discharge the material and cool for 4 h to obtain a rubber material.

[0125] Step 2: Preparation of silicone rubber material

[0126] The rubber material is put into an injection molding machine, the barrel temperature of the injection molding machine is 200° C., the nozzle temperature is 190° C., and the silicone rubber sealing ring precursor is obtained by injection molding.

[0127] Step 3: Prepare silicone rubber sealing ring

[0128] The silicone rubber sealing ring precursor was placed into a flat-plate vulcanizer at a temperature of 130° C. and a pressure of 0.35 MPa. The vulcanization treatment was performed for 25 minutes to obtain a silicone rubber sealing ring.

[0129] Embodiment 11

[0130] This embodiment provides a method for preparing a hybrid fluorosilicone rubber for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0131] Step 1: Prepare the rubber compound

[0132] Weigh: 9.0 kg of hybrid fluorosilicone rubber prepared in Example 8, 2.0 kg of hollow filler prepared in Example 2, 200.0 g of dibenzoyl peroxide, 1000.0 g of dibutyl phthalate, 500.0 g of epoxy soybean oil and 100.0 g of silicone defoamer, mix and add into an internal mixer. The internal mixing temperature is 140° C. and the time is 40 min. After the internal mixing is completed, discharge the material and cool for 5 h to obtain a rubber material.

[0133] Step 2: Preparation of silicone rubber material

[0134] The rubber material is put into an injection molding machine with a barrel temperature of 220° C. and a nozzle temperature of 240° C., and a silicone rubber sealing ring precursor is obtained by injection molding.

[0135] Step 3: Prepare silicone rubber sealing ring

[0136] The silicone rubber sealing ring precursor was placed into a flat-plate vulcanizer with a temperature of 150°C and a pressure of 0.50 MPa. The vulcanization treatment was performed for 35 minutes to obtain a silicone rubber sealing ring.

[0137] Example 12

[0138] This embodiment provides a method for preparing a hybrid fluorosilicone rubber for a high temperature resistant and corrosion resistant silicone rubber sealing ring, comprising the following steps:

[0139] Step 1: Prepare the rubber compound

[0140] Weigh: 9.0 kg of hybrid fluorosilicone rubber prepared in Example 9, 1.8 kg of hollow filler prepared in Example 3, 100.0 g of dibenzoyl peroxide, 800.0 g of dibutyl phthalate, 400.0 g of epoxy soybean oil and 80.0 g of silicone defoamer, mix and add into an internal mixer, the internal mixing temperature is 130 ° C, the time is 30 min, and after the internal mixing is completed, the material is discharged and cooled for 5 h to obtain.

[0141] Step 2: Preparation of silicone rubber material

[0142] The rubber material is put into an injection molding machine with a barrel temperature of 210° C. and a nozzle temperature of 220° C., and a silicone rubber sealing ring precursor is obtained by injection molding.

[0143] Step 3: Prepare silicone rubber sealing ring

[0144] The silicone rubber sealing ring precursor was placed into a flat-plate vulcanizer at a temperature of 140°C and a pressure of 0.40 MPa, and the vulcanization treatment was performed for 30 minutes to obtain a silicone rubber sealing ring.

[0145] Comparative Example 1

[0146] The difference between this comparative example and Example 12 is that, during the preparation of the modified fluorosilicone rubber used in step 1, no reinforcing filler is used.

[0147] Comparative Example 2

[0148] The difference between this comparative example and Example 12 is that, in the preparation process of the hollow filler used in step 1, step I is omitted, and the use of activated microspheres is omitted in step II.

[0149] Comparative Example 3

[0150] The difference between this comparative example and Example 12 is that in the preparation process of the modified fluorosilicone rubber used in step 1, step ① is omitted, and in step ③, the use of the modified end-capping agent is omitted.

[0151] Comparative Example 4

[0152] The difference between this comparative example and Example 12 is that in the preparation process of the modified fluorosilicone rubber used in step 1, octamethylcyclotetrasiloxane is used in an equal amount to replace 2,4,6,8-tetramethylcyclotetrasiloxane in step 2.

[0153] Performance Test:

[0154] The tensile strength, high temperature aging tensile strength change rate, corrosion mass change rate and corrosion tensile strength change rate of the silicone rubber sealing rings prepared in Examples 10-12 and Comparative Examples 1-3 were tested with reference to GB / T 5720-2008 "Test Methods for O-Rings".

[0155] The volume wear of the silicone rubber sealing rings prepared in Examples 10-12 and Comparative Examples 1-3 was tested with reference to the standard GB / T 9867-2008 "Determination of wear resistance of vulcanized rubber or thermoplastic rubber (rotating roller abrader method)", and the specific data are shown in Table 1.

[0156] Table 1-Performance test data of each sample

[0157]

[0158]

[0159] Data Analysis:

[0160] Comparing and analyzing the data in Table 1 above, the tensile strength of the silicone rubber sealing ring prepared by the present invention is 30.12MPa, the high temperature aging tensile strength change rate is 1.6%, the corrosion mass change rate is 1.0%, the corrosion tensile strength change rate is 1.8% and the volume wear amount is 20mm 3 ;

[0161] By comparing the data of Example 12 and the comparative example and comparative example 4, it can be found that the tensile strength and wear resistance of the silicone rubber sealing ring prepared in Example 12 are significantly improved, indicating that the present invention introduces highly active silicon-hydrogen bonds in the modified fluorosilicone resin by using 2,4,6,8-tetramethylcyclotetrasiloxane. In the process of preparing the hybrid fluorosilicone resin, the silicon-hydrogen bonds are cross-linked inside the segment, at the end, and in the reinforcing filler under the catalysis of the catalyst to form complex cyclic, cross-linked, and grafted structures, which ultimately significantly improves the segment complexity of the hybrid fluorosilicone resin, and ultimately significantly improves the tensile strength and wear resistance of the silicone rubber sealing ring;

[0162] By comparing the data of Example 12 and Comparative Example 2, it can be found that the high temperature resistance of the silicone rubber sealing ring prepared in Example 12 is significantly improved, indicating that the surface of the activated microspheres obtained after activation has a large number of active functional group hydroxyl groups, which are used as supporting materials in the process of preparing a gel-like structure by hydrolysis of aluminum chloride and preparing a composite filler by calcination, so that the hollow filler has a stable spherical porous structure. The spherical porous structure has a higher specific surface area, thereby providing more surface for heat exchange, thereby more effectively dissipating heat, and the spherical porous structure has a lower thermal conductivity and a unique geometric structure, so that the silicone rubber sealing ring can better withstand thermal stress, thereby improving the high temperature resistance of the material;

[0163] By comparing the data of Example 12 and Comparative Example 3, it can be found that the radiation resistance of the silicone rubber sealing ring prepared in Example 12 is significantly improved, indicating that by controlling the dosage ratio of the drug when the perfluoro group is introduced by photoinitiation on trivinylethoxysilane, the modified end-capping agent introduces a large number of fluorine groups and olefin structures at the ends of the modified fluorosilicone resin segments during the end-capping process, and in the process of preparing the hybrid fluorosilicone resin, it is coordinated with 3,5-bis(trifluoromethyl)phenyldimethylsilane through hydrosilylation, thereby significantly improving the corrosion resistance of the material;

[0164] The present invention introduces silicon hydrogen groups and double bond structures into the modified fluorosilicone resin, which form complex cyclic, cross-linked and grafted structures by cross-linking with the monomer structure and reinforcing fillers, thereby significantly improving the segment complexity of the hybrid fluorosilicone resin and introducing a large number of fluorine groups, thereby significantly improving the corrosion resistance, tensile strength and wear resistance of the hybrid fluorosilicone resin, and after mixing with hollow fillers and auxiliary materials and vulcanizing, a wear-resistant, tensile-resistant and high-temperature resistant corrosion-resistant silicone rubber sealing ring is obtained.

[0165] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high temperature resistant and corrosion resistant silicone rubber sealing ring, characterized in that: The raw material composition includes the following parts by weight: 80-100 parts of hybrid fluorosilicone rubber, 15-20 parts of hollow filler, 0.5-2 parts of vulcanizer, 5-10 parts of plasticizer, 3-5 parts of heat stabilizer and 0.5-1 parts of organosilicon defoamer; The preparation method of hybrid fluorosilicone rubber comprises the following steps: A1. Add modified fluorosilicone rubber and tetrahydrofuran into a reaction kettle, stir at room temperature for 10-15 minutes, add 3,5-bis(trifluoromethyl)phenyldimethylsilane into the reaction kettle, continue stirring for 3-5 minutes, and obtain a reaction precursor solution; A2. Add the reaction precursor liquid into the reactor. After the temperature of the reactor is raised to 40-60°C, add dihydrogen platinum and reinforcing filler into the reactor. Keep the temperature for 1-2 hours and perform post-treatment to obtain hybrid fluorosilicone rubber.

2. The high temperature resistant and corrosion resistant silicone rubber sealing ring according to claim 1, characterized in that: In step A1, the amount ratio of modified fluorosilicone rubber, tetrahydrofuran, and 3,5-bis(trifluoromethyl)phenyldimethylsilane is 8-10 g:60-80 mL:2-3 g; in step A2, the amount ratio of reaction precursor liquid, platinum dihydride, and reinforcing filler is 60-80 mL:0.3-0.5 g:2-3 g.

3. The high temperature resistant and corrosion resistant silicone rubber sealing ring according to claim 1, characterized in that: The preparation method of the modified fluorosilicone rubber comprises the following steps: B1, adding 2,4,6,8-tetramethylcyclotetrasiloxane, tetramethyldivinyldisiloxane and tetrahydrofuran into a reaction kettle, stirring at room temperature for 15-20 minutes to obtain a prepolymer solution; B2. Add the prepolymer liquid and the catalyst into the reactor, raise the temperature of the reactor to 40-60°C, keep the reaction warm for 2-3 hours, add the modified end-capping agent into the reactor, continue to keep the reaction warm for 40-60 minutes, add 5-8wt% ammonia solution into the reactor containing the reaction liquid until the pH value of the reaction liquid is 7-8, and obtain the modified fluorosilicone rubber by post-treatment.

4. The high temperature resistant and corrosion resistant silicone rubber sealing ring according to claim 1, characterized in that: In step B1, the amount ratio of 2,4,6,8-tetramethylcyclotetrasiloxane, tetramethyldivinyldisiloxane and tetrahydrofuran is 6-8g:8-10g:80-100mL; in step B2, the amount ratio of prepolymer solution, catalyst and modified end-capping agent is 40-50mL:5-6mL:4-6g, and the catalyst is 60-80wt% sulfuric acid solution.

5. The high temperature resistant and corrosion resistant silicone rubber sealing ring according to claim 3, characterized in that: The preparation method of the modified end-capping agent is as follows: trivinylethoxysilane and N,N-dimethylformamide are added to a reaction kettle, stirred at room temperature for 10-15 minutes, benzoin dimethyl ether and 1H,1H,2H,2H-perfluorodecyl mercaptan are added to the reaction kettle, irradiated with an ultraviolet lamp for 30-40 minutes, and then post-treated to obtain the modified end-capping agent.

6. The high temperature resistant and corrosion resistant silicone rubber sealing ring according to claim 5, characterized in that: The dosage ratio of trivinylethoxysilane, N,N-dimethylformamide, benzoin dimethyl ether and 1H,1H,2H,2H-perfluorodecyl mercaptan is 3-5g:20-30mL:0.3-0.5g:4-6g, and the wavelength of the ultraviolet lamp is 350-370nm.

7. The high temperature resistant and corrosion resistant silicone rubber sealing ring according to claim 5, characterized in that: The preparation method of the reinforcing filler comprises the following steps: C1. Add hollow glass balls and 3-4 wt% sodium hydroxide aqueous solution into a reaction kettle and stir. Raise the temperature of the reaction kettle to 50-60° C., keep the temperature for 1-2 hours, and perform post-treatment to obtain activated microspheres. C2, adding activated microspheres, aluminum chloride and anhydrous ethanol into a reactor and stirring, stirring at room temperature for 15-20 minutes, and then continuing to drop deionized water, after the temperature of the reactor is raised to 40-60°C, using 1-1.5 mol / L ammonia solution to adjust the system pH to 8-9, and heat preservation for 24-36 hours to obtain a mixed gel, and post-processing to obtain a composite filler; C3, adding the composite filler and 1-2 mol / L sodium hydroxide solution into a reactor, ultrasonicating for 3-5 hours at room temperature, and post-treating to obtain a hollow filler; C4. Add hollow filler, 5-hexenyltrimethoxysilane, sodium hydroxide and deionized water into the reactor, increase the temperature of the reactor to 30-50°C, keep the temperature for 3-5h, and post-treat to obtain the reinforced filler.

8. The high temperature resistant and corrosion resistant silicone rubber sealing ring according to claim 7, characterized in that: In step C1, the usage ratio of hollow glass balls and 3-4wt% sodium hydroxide aqueous solution is 1-2g:10-15mL; in step C2, the usage ratio of activated microspheres, aluminum chloride, anhydrous ethanol and deionized water is 1-2g:5-8g:30-40mL:10-20mL; in step C3, the usage ratio of composite filler and 1-2mol / L sodium hydroxide solution is 1g:20-30mL; in step C4, the usage ratio of hollow filler, 5-hexenyltrimethoxysilane, sodium hydroxide and deionized water is 8-10g:2-3g:0.8-1g:30-50mL.

9. A method for preparing a high temperature resistant and corrosion resistant silicone rubber sealing ring, using a high temperature resistant and corrosion resistant silicone rubber sealing ring as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Mix the hybrid fluorosilicone rubber, hollow filler, vulcanizer, plasticizer, heat stabilizer and organosilicon defoamer and add them into an internal mixer. The internal mixing temperature is 120-140°C for 20-40 minutes. After the internal mixing is completed, discharge the material and cool for 4-5 hours to obtain a rubber compound. S2, putting the rubber material into an injection molding machine, the barrel temperature of the injection molding machine is 200-220°C, the nozzle temperature is 190-240°C, and injection molding is performed to obtain a silicone rubber sealing ring precursor; S3. Put the silicone rubber sealing ring precursor into a flat vulcanizer and vulcanize it for 25-35 minutes to obtain a silicone rubber sealing ring.

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