Oil-resistant wear-resistant fluororubber sealing ring and processing technology thereof

Abstract

The invention discloses an oil-resistant and wear-resistant fluororubber sealing ring and a processing technology thereof. The invention relates to the technical field of rubber sealing rings. The oil-resistant and wear-resistant fluororubber sealing ring comprises the following main components in parts by mass: 70-80 parts of fluororubber, 10-20 parts of modified composite filler, 1-2 parts of an accelerant, 4-6 parts of a modified vulcanizing agent and 1-3 parts of an anti-aging agent, according to the fluororubber ring, the multiwalled carbon nanotubes are compounded with silicon dioxide, the wear resistance of the fluororubber ring is remarkably improved by utilizing the unique molecular structure of SiO2 and the relatively high bond energy of Si-O bonds as well as the multiwalled carbon nanotubes serving as carbon materials and having the effect of a rubber reinforcing agent, and on the basis, thioglycollic acid is used for further modification, so that the wear resistance of the fluororubber ring is improved, and the wear resistance of the fluororubber ring is improved. Meanwhile, the silane coupling agent is used for cooperating with the modified vulcanizing agent, so that the wear resistance and the stability of the fluororubber sealing ring are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of rubber sealing ring technology, specifically to an oil-resistant and wear-resistant fluororubber sealing ring and its processing technology. Background Technology

[0002] In modern industry, sealing rings are critical components widely used in automotive, aerospace, petrochemical, and other fields. Their main function is to prevent liquid or gas leakage, ensuring the normal operation and safety of equipment. However, traditional sealing ring materials often suffer from poor oil resistance, insufficient wear resistance, and short service life when facing high temperatures, high pressures, highly corrosive media, and complex operating conditions, making it difficult to meet the stringent requirements of modern industry for high-performance sealing materials.

[0003] In recent years, with the continuous advancement of materials science, fluororubber, as a high-performance synthetic rubber, has gradually become an ideal material for manufacturing sealing rings due to its excellent oil resistance, high-temperature resistance, and chemical corrosion resistance. The presence of fluorine atoms in its molecular structure endows fluororubber with excellent chemical and thermal stability, enabling it to maintain good sealing performance under extreme conditions. However, the wear resistance of fluororubber alone still needs improvement, especially under high-load, frequent reciprocating motion conditions, where it is prone to wear and deformation, leading to seal failure.

[0004] To address the above problems, this invention provides an oil-resistant and wear-resistant fluororubber sealing ring and its processing technology. Summary of the Invention

[0005] The purpose of this invention is to provide an oil-resistant and wear-resistant fluororubber sealing ring and its processing technology, so as to solve the problems mentioned in the background art. To solve the above-mentioned technical problems, this invention provides the following technical solution: A processing method for an oil-resistant and wear-resistant fluororubber sealing ring, characterized by the following steps: Step 1: Mix fluororubber at 40-50℃, add modified composite filler, and then add accelerator, modified vulcanizing agent and antioxidant in sequence, and mix to obtain compound rubber; Step 2: After the rubber compound has been left to stand for 24 hours, it is pressed and vulcanized at a temperature of 160-180℃ and a pressure of 20-30MPa. Then, a second-stage vulcanization is carried out at a temperature of 220-240℃ for 7-9 hours. The rubber is then sheeted, cut, trimmed, and polished to obtain an oil-resistant and wear-resistant fluororubber sealing ring.

[0006] Furthermore, the oil-resistant and wear-resistant fluororubber sealing ring comprises the following components, by weight: 70-80 parts fluororubber, 10-20 parts modified composite filler, 1-2 parts accelerator, 4-6 parts modified vulcanizing agent, and 1-3 parts antioxidant.

[0007] Furthermore, the modified composite filler is prepared by dispersing silica-carbon nanotube composite powder in ethanol, sonicating for 20-40 min, adding mercaptoacetic acid, stirring and reacting at 50-60℃ for 1-2 h to ensure thorough mixing of mercaptoacetic acid; centrifuging, washing, and drying to obtain the modified composite filler.

[0008] Furthermore, the preparation method of the silica-carbon nanotube composite powder is as follows: prepare a sodium silicate solution and a phosphoric acid solution, add boric acid solution to the sodium silicate solution to adjust the pH to 1.0-2.0; add modified multi-walled carbon nanotubes, seal and stir for 1-2 hours to obtain a mixed solution; prepare a sodium hydroxide solution, add the sodium hydroxide solution dropwise to the mixed solution, adjust the pH to neutral, age at room temperature for 22-24 hours, and freeze-dry for 46-48 hours to obtain the silica-carbon nanotube composite powder.

[0009] Furthermore, the preparation method of the modified multi-walled carbon nanotubes is as follows: FeSO4·7H2O is dissolved in distilled water to obtain an aqueous solution of FeSO4·7H2O. Then, multi-walled carbon nanotube powder is added to the FeSO4·7H2O aqueous solution and ultrasonically vibrated for 30-50 min to obtain a mixed solution. Hydrogen peroxide is added dropwise to the mixed solution, magnetically stirred, and reacted for 10-12 h. After filtration, washing, and drying, oxidized multi-walled carbon nanotubes can be obtained. 200 mL of anhydrous ethanol and 20 g of titanate coupling agent are added to the oxidized multi-walled carbon nanotubes, ultrasonically vibrated, cooled, filtered, washed, and dried to obtain modified multi-walled carbon nanotubes.

[0010] Furthermore, the modified vulcanizing agent is prepared by adding silane coupling agent to distilled water and mixing evenly, adding anhydrous ethanol to prepare a silane coupling agent solution, letting it stand for 2 hours, adding nano zinc oxide, ultrasonically dispersing, adjusting the pH to 3.0-3.5 with glacial acetic acid, stirring, washing, and drying to obtain the modified vulcanizing agent.

[0011] Furthermore, the sodium silicate solution has a mass fraction of 30-40%, and the phosphoric acid solution has a concentration of 5-7 mol / L.

[0012] Furthermore, the titanate coupling agent is titanate coupling agent QX201.

[0013] Furthermore, the silane coupling agent is silane coupling agent KH550, and the mass fraction of the silane coupling agent solution is 3-4%.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: (1) Carbon nanotubes are widely used in the reinforcement system of various elastomers due to their unique atomic structure. When combined with silica, they can be used to obtain composite fillers that can further improve the wear resistance of materials. This improvement of composite materials is due to the unique molecular structure of SiO2 and the relatively high bond energy of Si-O bonds. On the other hand, it is due to the fact that multi-walled carbon nanotubes themselves act as rubber reinforcing agents as carbon materials. The composite modification of the two reinforcing agents to prepare fillers and filling them at low concentrations can produce a reinforcing effect on composite materials and further increase wear resistance. The titanate coupling agent QX201 grafted on the surface of multi-walled carbon nanotubes increases the specific surface area of ​​multi-walled carbon nanotubes, reduces the surface energy of multi-walled carbon nanotubes, and promotes the uniform dispersion of multi-walled carbon nanotubes in the matrix. Furthermore, the use of mercaptoacetic acid to modify and graft the composite filler can allow mercapto groups to participate in the vulcanization process of rubber, further promoting the vulcanization process and activation effect, thereby improving the mechanical properties of rubber.

[0015] (2) For the vulcanizing activator nano zinc oxide, silane coupling agent is selected for modification. The silane coupling agent contains a unique silicon-oxygen bond (Si-O) structure. This structure makes the siloxane molecule have good flexibility and low surface energy. When the silane coupling agent is blended with fluororubber, the silicon-oxygen bond in the siloxane molecule can interact with the fluorine atom in the fluororubber molecule. At the same time, the silica in the modified composite filler also contains silicon-oxygen bonds, which helps to improve the compatibility between fluororubber and composite modified filler, making the matrix structure of the rubber ring more stable and obtaining a sealing ring with excellent wear resistance and mechanical properties. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The sources and types of substances involved in this invention are not particularly limited. Exemplary examples include the following raw materials: fluororubber: type: P959, fluorine content 70%, which can be purchased from Solvay; vulcanizing agent: triallyl isocyanurate: 75%, which can be purchased from Rhein Chemical (Qingdao) Co., Ltd.; nano zinc oxide powder: particle size: 10-20nm; multi-walled carbon nanotubes: type: TNM3, outer diameter: 10~20nm, mass fraction >98%, which can be purchased from Chengdu Organic Chemistry Co., Ltd., Chinese Academy of Sciences. Example

[0018] Step 1: Preparation of modified multi-walled carbon nanotubes Weigh 50g of FeSO4·7H2O into a 500mL Erlenmeyer flask, add 200mL of distilled water to dissolve it, and obtain an aqueous solution of FeSO4·7H2O. Then weigh 5g of multi-walled carbon nanotube powder into the FeSO4·7H2O aqueous solution and sonicate for 30min to obtain a mixed solution. Add 120mL of hydrogen peroxide dropwise to the mixed solution while stirring with a magnetic stirrer during the addition. React for 10h, filter, wash, and dry to obtain oxidized multi-walled carbon nanotubes. 3g of oxidized multi-walled carbon nanotubes were weighed into a 500mL Erlenmeyer flask, followed by the addition of 200mL of anhydrous ethanol and 20g of titanate coupling agent QX201. The mixture was ultrasonically vibrated and magnetically stirred at 70℃ for 7h. After cooling, filtration, washing, and drying, modified multi-walled carbon nanotubes were obtained. Step 2: Preparation of modified composite filler 50 mL of 34% sodium silicate solution was prepared as a silicon source to introduce SiO2. A 6 mol / L phosphoric acid solution was prepared. Boric acid solution was added to the sodium silicate solution to adjust the pH to 1.0. 5 g of modified multi-walled carbon nanotubes were added, and the mixture was sealed and stirred for 1 h to obtain a mixed solution. A 1 mol / L sodium hydroxide solution was prepared and added dropwise to the mixed solution to adjust the pH to neutral. The mixture was aged at room temperature for 22 h and then freeze-dried for 46 h to obtain silica-carbon nanotube composite powder. 10g of silica-carbon nanotube composite powder was dispersed in 100mL of ethanol and sonicated for 20min. Then, 0.8g of mercaptoacetic acid was added and the mixture was stirred at 50-60℃ for 1h to ensure thorough mixing of the mercaptoacetic acid. The mixture was then centrifuged, washed, and dried to obtain the modified composite filler. Step 3: Preparation of Modified Vulcanizing Agent 0.35g of silane coupling agent KH550 was added to distilled water and mixed evenly. Anhydrous ethanol was added to prepare a solution of silane coupling agent KH550 with a mass fraction of 3.5%, wherein the volume ratio of distilled water to anhydrous ethanol was 1:3. After standing for 2 hours, 5g of nano zinc oxide was added, and the mixture was ultrasonically dispersed. The pH was adjusted to 3.5 with glacial acetic acid, and the mixture was stirred, washed, and dried to obtain the modified vulcanizing agent. Step 4: Preparation of oil-resistant and wear-resistant fluororubber sealing rings Take 70 parts by weight of fluororubber and put it into a two-roll mill. Set the roll temperature to 40℃. Add 10 parts by weight of modified composite filler. Then add 1 part by weight of accelerator triallyl isocyanurate, 4 parts by weight of modified vulcanizing agent and 1 part by weight of antioxidant 4-isopropylaminodiphenylamine in sequence and mix to obtain the compound rubber. After the rubber compound is left to stand for 24 hours, it is pressed and vulcanized at a vulcanization temperature of 160℃ and a vulcanization pressure of 20MPa. Then, a second vulcanization is carried out at a vulcanization temperature of 220℃ for 7 hours. After pressing, cutting, trimming and grinding the rubber edges, an oil-resistant and wear-resistant fluororubber sealing ring is obtained. Example

[0019] Step 1: Preparation of modified multi-walled carbon nanotubes Weigh 50g of FeSO4·7H2O into a 500mL Erlenmeyer flask, add 200mL of distilled water to dissolve it, and obtain an aqueous solution of FeSO4·7H2O. Then weigh 5g of multi-walled carbon nanotube powder into the FeSO4·7H2O aqueous solution and sonicate for 40min to obtain a mixed solution. Add 135mL of hydrogen peroxide dropwise to the mixed solution while stirring with a magnetic stirrer during the dropwise addition. React for 11h, filter, wash, and dry to obtain oxidized multi-walled carbon nanotubes. 3g of oxidized multi-walled carbon nanotubes were weighed into a 500mL Erlenmeyer flask, followed by the addition of 200mL of anhydrous ethanol and 20g of titanate coupling agent QX201. The mixture was ultrasonically vibrated and magnetically stirred at 75℃ for 8 hours. After cooling, filtration, washing, and drying, modified multi-walled carbon nanotubes were obtained. Step 2: Preparation of modified composite filler 50 mL of 34% sodium silicate solution was prepared as a silicon source to introduce SiO2. A 6 mol / L phosphoric acid solution was prepared, and boric acid solution was added to the sodium silicate solution to adjust the pH to 1.5. 5 g of modified multi-walled carbon nanotubes were added, and the mixture was sealed and stirred for 1.5 h to obtain a mixed solution. A 1 mol / L sodium hydroxide solution was prepared, and the mixed solution was added dropwise to adjust the pH to neutral. The mixture was aged at room temperature for 23 h and then freeze-dried for 47 h to obtain silica-carbon nanotube composite powder. 10g of silica-carbon nanotube composite powder was dispersed in 100mL of ethanol and sonicated for 20-40min. Then, 0.8g of mercaptoacetic acid was added and the mixture was stirred at 50-60℃ for 1.5h to ensure thorough mixing of the mercaptoacetic acid. The mixture was then centrifuged, washed, and dried to obtain the modified composite filler. Step 3: Preparation of Modified Vulcanizing Agent 0.35g of silane coupling agent KH550 was added to distilled water and mixed evenly. Anhydrous ethanol was added to prepare a solution of silane coupling agent KH550 with a mass fraction of 3.5%, wherein the volume ratio of distilled water to anhydrous ethanol was 1:3. After standing for 2 hours, 5g of nano zinc oxide was added, and the mixture was ultrasonically dispersed. The pH was adjusted to 3.5 with glacial acetic acid, and the mixture was stirred, washed, and dried to obtain the modified vulcanizing agent. Step 4: Preparation of oil-resistant and wear-resistant fluororubber sealing rings Take 75 parts by weight of fluororubber and put it into a two-roll mill. Set the roll temperature to 45℃. Add 15 parts by weight of modified composite filler. Then add 1.5 parts by weight of accelerator triallyl isocyanurate, 5 parts by weight of modified vulcanizing agent and 2 parts by weight of antioxidant 4-isopropylaminodiphenylamine in sequence and mix to obtain the compound rubber. After the rubber compound is left to stand for 24 hours, it is pressed and vulcanized at a vulcanization temperature of 170℃ and a vulcanization pressure of 25MPa. Then, a second vulcanization is carried out at a vulcanization temperature of 230℃ for 8 hours. After pressing, cutting, trimming and grinding the rubber edges, an oil-resistant and wear-resistant fluororubber sealing ring is obtained. Example

[0020] Step 1: Preparation of modified multi-walled carbon nanotubes Weigh 50g of FeSO4·7H2O into a 500mL Erlenmeyer flask, add 200mL of distilled water to dissolve it, and obtain an aqueous solution of FeSO4·7H2O. Then weigh 5g of multi-walled carbon nanotube powder into the FeSO4·7H2O aqueous solution and sonicate for 50min to obtain a mixed solution. Add 150mL of hydrogen peroxide dropwise to the mixed solution while stirring with a magnetic stirrer during the addition. React for 12h, filter, wash, and dry to obtain oxidized multi-walled carbon nanotubes. 3g of oxidized multi-walled carbon nanotubes were weighed into a 500mL Erlenmeyer flask, followed by the addition of 200mL of anhydrous ethanol and 20g of titanate coupling agent QX201. The mixture was ultrasonically vibrated and magnetically stirred at 80℃ for 9h. After cooling, filtration, washing, and drying, modified multi-walled carbon nanotubes were obtained. Step 2: Preparation of modified composite filler 50 mL of 34% sodium silicate solution was prepared as a silicon source to introduce SiO2. A 6 mol / L phosphoric acid solution was prepared, and boric acid solution was added to the sodium silicate solution to adjust the pH to 2.0. 5 g of modified multi-walled carbon nanotubes were added, the mixture was sealed and stirred for 2 h to obtain a mixed solution. A 1 mol / L sodium hydroxide solution was prepared, and the mixed solution was added dropwise to adjust the pH to neutral. The mixture was aged at room temperature for 24 h and then freeze-dried for 48 h to obtain silica-carbon nanotube composite powder. 10g of silica-carbon nanotube composite powder was dispersed in 100mL of ethanol and sonicated for 40min. Then, 0.8g of mercaptoacetic acid was added and stirred at 60℃ for 2h to ensure thorough mixing of the mercaptoacetic acid. The mixture was then centrifuged, washed, and dried to obtain the modified composite filler. Step 3: Preparation of Modified Vulcanizing Agent 0.35g of silane coupling agent KH550 was added to distilled water and mixed evenly. Anhydrous ethanol was added to prepare a solution of silane coupling agent KH550 with a mass fraction of 3.5%, wherein the volume ratio of distilled water to anhydrous ethanol was 1:3. After standing for 2 hours, 5g of nano zinc oxide was added, and the mixture was ultrasonically dispersed. The pH was adjusted to 3.5 with glacial acetic acid, and the mixture was stirred, washed, and dried to obtain the modified vulcanizing agent. Step 4: Preparation of oil-resistant and wear-resistant fluororubber sealing rings Take 80 parts by weight of fluororubber and put it into a two-roll mill. Set the roll temperature to 50℃. Add 20 parts by weight of modified composite filler. Then add 2 parts by weight of accelerator triallyl isocyanurate, 6 parts by weight of modified vulcanizing agent, and 3 parts by weight of antioxidant 4-isopropylaminodiphenylamine in sequence and mix to obtain the compound rubber. After the rubber compound is left to stand for 24 hours, it is pressed and vulcanized at a vulcanization temperature of 180℃ and a vulcanization pressure of 30MPa. Then, a second vulcanization is carried out at a vulcanization temperature of 240℃ for 9 hours. After pressing, cutting, trimming and grinding the rubber edges, an oil-resistant and wear-resistant fluororubber sealing ring is obtained.

[0021] Comparative Example 1: Modification of the vulcanizing agent nano zinc oxide without the addition of silane coupling agent KH550, otherwise the same as in Example 1; specifically: Step 1: Preparation of modified multi-walled carbon nanotubes Weigh 50g of FeSO4·7H2O into a 500mL Erlenmeyer flask, add 200mL of distilled water to dissolve it, and obtain an aqueous solution of FeSO4·7H2O. Then weigh 5g of multi-walled carbon nanotube powder into the FeSO4·7H2O aqueous solution and sonicate for 30min to obtain a mixed solution. Add 120mL of hydrogen peroxide dropwise to the mixed solution while stirring with a magnetic stirrer during the addition. React for 10h, filter, wash, and dry to obtain oxidized multi-walled carbon nanotubes. 3g of oxidized multi-walled carbon nanotubes were weighed into a 500mL Erlenmeyer flask, followed by the addition of 200mL of anhydrous ethanol and 20g of titanate coupling agent QX201. The mixture was ultrasonically vibrated and magnetically stirred at 70℃ for 7h. After cooling, filtration, washing, and drying, modified multi-walled carbon nanotubes were obtained. Step 2: Preparation of modified composite filler 50 mL of 34% sodium silicate solution was prepared as a silicon source to introduce SiO2. A 6 mol / L phosphoric acid solution was prepared. Boric acid solution was added to the sodium silicate solution to adjust the pH to 1.0. 5 g of modified multi-walled carbon nanotubes were added, and the mixture was sealed and stirred for 1 h to obtain a mixed solution. A 1 mol / L sodium hydroxide solution was prepared and added dropwise to the mixed solution to adjust the pH to neutral. The mixture was aged at room temperature for 22 h and then freeze-dried for 46 h to obtain silica-carbon nanotube composite powder. 10g of silica-carbon nanotube composite powder was dispersed in 100mL of ethanol and sonicated for 20min. Then, 0.8g of mercaptoacetic acid was added and the mixture was stirred at 50-60℃ for 1h to ensure thorough mixing of the mercaptoacetic acid. The mixture was then centrifuged, washed, and dried to obtain the modified composite filler. Step 3: Preparation of oil-resistant and wear-resistant fluororubber sealing rings Take 70 parts by weight of fluororubber and put it into a two-roll mill. Set the roll temperature to 40℃. Add 10 parts by weight of modified composite filler. Then add 1 part by weight of accelerator triallyl isocyanurate, 4 parts by weight of vulcanizing agent nano zinc oxide and 1 part by weight of antioxidant 4-isopropylaminodiphenylamine in sequence and mix to obtain the compound rubber. After the rubber compound is left to stand for 24 hours, it is pressed and vulcanized at a vulcanization temperature of 160℃ and a vulcanization pressure of 20MPa. Then, a second vulcanization is carried out at a vulcanization temperature of 220℃ for 7 hours. After pressing, cutting, trimming and grinding the rubber edges, an oil-resistant and wear-resistant fluororubber sealing ring is obtained.

[0022] Comparative Example 2: Modification of oxidized multi-walled carbon nanotubes without the addition of titanate coupling agent, otherwise the same as in Example 1; specifically: Step 1: Preparation of Oxide Multi-Walled Carbon Nanotubes Weigh 50g of FeSO4·7H2O into a 500mL Erlenmeyer flask, add 200mL of distilled water to dissolve it, and obtain an aqueous solution of FeSO4·7H2O. Then weigh 5g of multi-walled carbon nanotube powder into the FeSO4·7H2O aqueous solution and sonicate for 30min to obtain a mixed solution. Add 120mL of hydrogen peroxide dropwise to the mixed solution while stirring with a magnetic stirrer during the addition. React for 10h, filter, wash, and dry to obtain oxidized multi-walled carbon nanotubes. Step 2: Preparation of modified composite filler 50 mL of 34% sodium silicate solution was prepared as a silicon source to introduce SiO2. A 6 mol / L phosphoric acid solution was prepared. Boric acid solution was added to the sodium silicate solution to adjust the pH to 1.0. 5 g of oxidized multi-walled carbon nanotubes were added, the mixture was sealed and stirred for 1 h to obtain a mixed solution. A 1 mol / L sodium hydroxide solution was prepared and added dropwise to the mixed solution to adjust the pH to neutral. The mixture was aged at room temperature for 22 h and then freeze-dried for 46 h to obtain silica-carbon nanotube composite powder. 10g of silica-carbon nanotube composite powder was dispersed in 100mL of ethanol and sonicated for 20min. Then, 0.8g of mercaptoacetic acid was added and the mixture was stirred at 50-60℃ for 1h to ensure thorough mixing of the mercaptoacetic acid. The mixture was then centrifuged, washed, and dried to obtain the modified composite filler. Step 3: Preparation of Modified Vulcanizing Agent 0.35g of silane coupling agent KH550 was added to distilled water and mixed evenly. Anhydrous ethanol was added to prepare a solution of silane coupling agent KH550 with a mass fraction of 3.5%, wherein the volume ratio of distilled water to anhydrous ethanol was 1:3. After standing for 2 hours, 5g of nano zinc oxide was added, and the mixture was ultrasonically dispersed. The pH was adjusted to 3.5 with glacial acetic acid, and the mixture was stirred, washed, and dried to obtain the modified vulcanizing agent. Step 4: Preparation of oil-resistant and wear-resistant fluororubber sealing rings Take 70 parts by weight of fluororubber and put it into a two-roll mill. Set the roll temperature to 40℃. Add 10 parts by weight of modified composite filler. Then add 1 part by weight of accelerator triallyl isocyanurate, 4 parts by weight of modified vulcanizing agent and 1 part by weight of antioxidant 4-isopropylaminodiphenylamine in sequence and mix to obtain the compound rubber. After the rubber compound is left to stand for 24 hours, it is pressed and vulcanized at a vulcanization temperature of 160℃ and a vulcanization pressure of 20MPa. Then, a second vulcanization is carried out at a vulcanization temperature of 220℃ for 7 hours. After pressing, cutting, trimming and grinding the rubber edges, an oil-resistant and wear-resistant fluororubber sealing ring is obtained.

[0023] Comparative Example 3: Modification of silica-carbon nanotube composite powder without the addition of mercaptoacetic acid, otherwise the same as in Example 1; specifically: Step 1: Preparation of modified multi-walled carbon nanotubes Weigh 50g of FeSO4·7H2O into a 500mL Erlenmeyer flask, add 200mL of distilled water to dissolve it, and obtain an aqueous solution of FeSO4·7H2O. Then weigh 5g of multi-walled carbon nanotube powder into the FeSO4·7H2O aqueous solution and sonicate for 30min to obtain a mixed solution. Add 120mL of hydrogen peroxide dropwise to the mixed solution while stirring with a magnetic stirrer during the addition. React for 10h, filter, wash, and dry to obtain oxidized multi-walled carbon nanotubes. 3g of oxidized multi-walled carbon nanotubes were weighed into a 500mL Erlenmeyer flask, followed by the addition of 200mL of anhydrous ethanol and 20g of titanate coupling agent QX201. The mixture was ultrasonically vibrated and magnetically stirred at 70℃ for 7h. After cooling, filtration, washing, and drying, modified multi-walled carbon nanotubes were obtained. Step 2: Preparation of silica-carbon nanotube composite powder 50 mL of 34% sodium silicate solution was prepared as a silicon source to introduce SiO2. A 6 mol / L phosphoric acid solution was prepared. Boric acid solution was added to the sodium silicate solution to adjust the pH to 1.0. 5 g of modified multi-walled carbon nanotubes were added, and the mixture was sealed and stirred for 1 h to obtain a mixed solution. A 1 mol / L sodium hydroxide solution was prepared and added dropwise to the mixed solution to adjust the pH to neutral. The mixture was aged at room temperature for 22 h and then freeze-dried for 46 h to obtain silica-carbon nanotube composite powder. Step 3: Preparation of Modified Vulcanizing Agent 0.35g of silane coupling agent KH550 was added to distilled water and mixed evenly. Anhydrous ethanol was added to prepare a solution of silane coupling agent KH550 with a mass fraction of 3.5%, wherein the volume ratio of distilled water to anhydrous ethanol was 1:3. After standing for 2 hours, 5g of nano zinc oxide was added, and the mixture was ultrasonically dispersed. The pH was adjusted to 3.5 with glacial acetic acid, and the mixture was stirred, washed, and dried to obtain the modified vulcanizing agent. Step 4: Preparation of oil-resistant and wear-resistant fluororubber sealing rings Take 70 parts by weight of fluororubber and put it into a two-roll mill. Set the roll temperature to 40℃. Add 10 parts by weight of silica-carbon nanotube composite powder. Then, add 1 part by weight of accelerator triallyl isocyanurate, 4 parts by weight of modified vulcanizing agent and 1 part by weight of antioxidant 4-isopropylaminodiphenylamine in sequence and mix to obtain the compound rubber. After the rubber compound is left to stand for 24 hours, it is pressed and vulcanized at a vulcanization temperature of 160℃ and a vulcanization pressure of 20MPa. Then, a second vulcanization is carried out at a vulcanization temperature of 220℃ for 7 hours. After pressing, cutting, trimming and grinding the rubber edges, an oil-resistant and wear-resistant fluororubber sealing ring is obtained.

[0024] experiment: (1) Tensile property test: Referring to GB / T528-2009 standard, the oil-resistant and wear-resistant fluororubber sealing rings prepared in Examples 1-3 and Comparative Examples 1-3 were cut into samples with an inner diameter of 44.6 mm and a thickness of 4.4 mm. The samples were tested using an electronic tensile testing machine with a tensile rate of 500 mm / min. (2) Abrasion resistance test: The test was conducted according to GB / 9867-2008 using a DIN abrasion tester. Oil-resistant and abrasion-resistant fluororubber sealing rings prepared in Examples 1-3 and Comparative Examples 1-3 were cut into samples with a diameter of 16 mm and a height of 8 mm. Under test conditions of a friction distance of 40 m and a load of 10 N, the abrasion resistance of the samples was expressed as the wear volume. The obtained data are shown in Table 1 below.

[0025] Conclusion: Comparison of the data in the table shows that in Comparative Example 1, the lack of addition of silane coupling agent KH550 to modify the nano-zinc oxide vulcanizing agent resulted in a lack of synergistic effect between the silicon-oxygen bonds and the SiO2 in the modified composite filler, leading to poor compatibility between the fluororubber and the filler. This severely affected the mechanical strength of the rubber seal, resulting in a significant decrease in tensile strength and wear resistance. In Comparative Example 2, the lack of addition of titanate coupling agent to modify the oxidized multi-walled carbon nanotubes resulted in a decrease in the surface area of ​​the multi-walled carbon nanotubes, an increase in surface energy, and a decrease in reactivity, leading to an overall decrease in the mechanical properties of the rubber seal. In Comparative Example 3, the lack of addition of mercaptoacetic acid to modify the silica-carbon nanotube composite powder resulted in a decrease in the vulcanization activity of the rubber due to the absence of mercapto groups, leading to poor vulcanization effect and a significant decrease in the wear resistance of the rubber seal. In summary, the method provided by this invention can produce an oil-resistant and wear-resistant fluororubber seal with good stability and mechanical properties.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0027] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A processing technology for an oil-resistant and wear-resistant fluororubber sealing ring, characterized in that: The method comprises the following steps: Step 1: fluorine rubber is mixed at 40-50 DEG C, then modified composite filler is added, and then accelerator, modified vulcanizing agent and antioxidant are added in sequence, and mixing is performed to obtain a mixed rubber; Step 2: the mixed rubber is placed for 24 hours, then pressing and vulcanization are performed at a vulcanization temperature of 160-180 DEG C and a vulcanization pressure of 20-30 MPa, then secondary vulcanization is performed at a vulcanization temperature of 220-240 DEG C for 7-9 hours, and then pressing, cutting, trimming and polishing of the rubber edge are performed to obtain the oil-resistant and wear-resistant fluorine rubber sealing ring.

2. The process for processing oil resistant and abrasion resistant fluoroelastomer seal ring as claimed in claim 1 wherein: The oil-resistant and wear-resistant fluorine rubber sealing ring comprises the following components in parts by weight: 70-80 parts of fluorine rubber, 10-20 parts of modified composite filler, 1-2 parts of accelerator, 4-6 parts of modified vulcanizing agent and 1-3 parts of antioxidant.

3. The process for processing oil resistant and abrasion resistant fluoroelastomer seal ring as claimed in claim 1 wherein: The preparation method of the modified composite filler is as follows: the silicon dioxide-carbon nanotube composite powder is dispersed in ethanol, ultrasonic treatment is performed for 20-40 minutes, mercaptoacetic acid is added, stirring is performed at 50-60 DEG C for 1-2 hours to fully mix the mercaptoacetic acid, centrifugal separation, washing and drying are performed to obtain the modified composite filler.

4. The process for processing oil resistant and abrasion resistant fluoroelastomer seal ring as claimed in claim 3 wherein: The preparation method of the silicon dioxide-carbon nanotube composite powder is as follows: sodium silicate solution and phosphoric acid solution are prepared, boric acid solution is added to the sodium silicate solution to adjust the pH, and the pH of the system is adjusted to 1.0-2.0; Modified multi-walled carbon nanotubes are added, sealing and stirring are performed for 1-2 hours to obtain a mixed solution, sodium hydroxide solution is prepared, the sodium hydroxide solution is added dropwise into the mixed solution, the pH is adjusted to neutral, aging is performed at room temperature for 22-24 hours, and freeze-drying is performed for 46-48 hours to obtain the silicon dioxide-carbon nanotube composite powder.

5. The process for processing oil resistant and abrasion resistant fluoroelastomer seal ring as claimed in claim 4 wherein: The preparation method of the modified multi-walled carbon nanotube is as follows: FeSO4.7H2O is dissolved in distilled water to obtain FeSO4.7H2O aqueous solution, then multi-walled carbon nanotube powder is added into the FeSO4.7H2O aqueous solution, ultrasonic oscillation is performed for 30-50 minutes to obtain a mixed solution, hydrogen peroxide is added dropwise into the mixed solution, magnetic stirring is performed, reaction is performed for 10-12 hours, and then the mixed solution is subjected to filtration, washing and drying to obtain oxidized multi-walled carbon nanotube; anhydrous ethanol and titanate coupling agent are added into the oxidized multi-walled carbon nanotube, ultrasonic oscillation is performed, magnetic stirring is performed at 70-80 DEG C for 7-9 hours, and then the mixture is cooled, filtered, washed and dried to obtain the modified multi-walled carbon nanotube.

6. The process for processing oil resistant and abrasion resistant fluoroelastomer seal ring as claimed in claim 1 wherein: The preparation method of the modified vulcanizing agent is as follows: silane coupling agent is added into distilled water and mixed uniformly, anhydrous ethanol is added, a silane coupling agent solution is prepared, the solution is left to stand for 2 hours, nano-zinc oxide is added, ultrasonic dispersion is performed, glacial acetic acid is used to adjust the pH to 3.0-3.5, and then stirring, washing and drying are performed to obtain the modified vulcanizing agent.

7. The process for processing oil resistant and abrasion resistant fluoroelastomer seal ring as claimed in claim 4 wherein: The mass fraction of the sodium silicate solution is 30-40%, and the concentration of the phosphoric acid solution is 5-7 mol / L.

8. The process for processing oil resistant and abrasion resistant fluoroelastomer seal ring as claimed in claim 5 wherein: The titanate coupling agent is titanate coupling agent QX201.

9. The process for processing oil resistant and abrasion resistant fluoroelastomer seal ring as claimed in claim 6 wherein: The silane coupling agent is silane coupling agent KH550, and the mass fraction of the silane coupling agent solution is 3-4%.

10. The oil-resistant and wear-resistant fluorine rubber sealing ring obtained by the processing technology according to any one of claims 1-9.

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