Anti-aging rubber sealing material for oil field drilling and preparation method of anti-aging rubber sealing material
By introducing modified talc and silica into rubber sealing materials, and combining them with macromolecular and small molecule silane coupling agents, the aging problem of rubber materials under extreme environments was solved, achieving good oil resistance and anti-aging properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-27
- Publication Date
- 2026-05-01
AI Technical Summary
Existing rubber sealing materials are prone to aging and failure under high temperature, high pressure, high wear and corrosive media environments. Traditional methods have limited effectiveness in improving aging resistance, and inorganic reinforcing agents have prominent dispersibility and compatibility issues.
By using modified talc and silica in specific proportions as reinforcing agents and modifying them with different macromolecular and small molecule silane coupling agents, their dispersibility and interfacial compatibility in rubber are improved, forming a stable chemical cross-linked structure.
It significantly improves the oil resistance and aging resistance of rubber sealing materials, delays oxidative aging, reduces oil molecule penetration, and enhances the stability and durability of the materials.
Smart Images
Figure SMS_1
Abstract
Description
An aging-resistant rubber sealing material for oilfield drilling and its preparation method Technical Field
[0001] This invention relates to the field of rubber materials technology, specifically to an aging-resistant rubber sealing material for oilfield drilling and its preparation method. Background Technology
[0002] Oilfield drilling equipment operates in extreme environments characterized by high temperatures, high pressures, high abrasion, and corrosive media rich in hydrogen sulfide and carbon dioxide. The durability of rubber seals in critical components directly impacts the safety and continuity of drilling operations. While traditional rubber sealing materials possess certain oil and media resistance, they are prone to cross-linking network degradation or excessive cross-linking under the combined effects of long-term thermo-oxidative aging, cyclic stress, and media penetration. This leads to seal failure, causing equipment malfunctions and safety risks. Therefore, long-term aging-resistant rubber sealing materials have become an urgent requirement for improving oilfield drilling equipment.
[0003] Existing technologies often focus on adding antioxidants to reduce the probability of rubber molecular chain breakage and increase crosslinking density, thereby enhancing the oil resistance and aging resistance of rubber materials. However, organic antioxidants are gradually consumed and migrate under high temperatures and complex media environments, leading to an accelerated rubber aging process. Introducing inorganic reinforcing agents can improve the aging resistance of rubber; however, dispersibility and compatibility issues exist. Although coupling agents can improve this defect, existing technologies often use a single coupling agent to treat inorganic particles of different morphologies, without fully considering the crucial impact of morphological differences on the dispersion effect, resulting in limited improvement in oil resistance and aging resistance.
[0004] Therefore, solving the above problems and providing an aging-resistant rubber sealing material for oilfield drilling and its preparation method is of great significance. Summary of the Invention
[0005] The purpose of this invention is to provide an aging-resistant rubber sealing material for oilfield drilling and its preparation method, so as to solve the problems raised in the prior art.
[0006] To achieve the above objectives, the present invention provides the following technical solution: an aging-resistant rubber sealing material for oilfield drilling, wherein the raw materials of the aging-resistant rubber sealing material, by weight, are: 40-60 parts hydrogenated nitrile rubber, 10-20 parts EPDM rubber, 30-40 parts reinforcing agent, 2-4 parts vulcanizing agent, 1.5-2.5 parts accelerator, 1-2 parts antioxidant, and 0.5-1 part stearic acid.
[0007] In a more optimized manner, the reinforcing agent is composed of modified talc and modified silica in a mass ratio of (5.5~7):(2.5~3).
[0008] The modified talc powder is prepared in a more optimized manner as follows: Step 1: (1) Magnesium shavings, allyl chloride, and methyldichlorosilane are added to tetrahydrofuran in sequence, heated to 55-65°C, stirred for 2-3 hours, extracted, dried, and rotary evaporated to obtain methyldiallyl silane; (2) Methyldiallyl silane and n-hexane are mixed, and Karstedt catalyst is added. The mixture is stirred at 70-80°C for 7-9 hours. After rotary evaporation, vinyl silicone oil and triethoxysilane are added in sequence. The mixture is stirred at 65-75°C for 7-9 hours and rotary evaporated to obtain an organosilicon polymer coupling agent; Step 2: Talc powder is added to an ethanol aqueous solution, the pH value is adjusted to 5-6, stirred evenly, and then the organosilicon polymer coupling agent is added. The mixture is stirred for 1-3 hours, centrifuged, washed with water, and vacuum dried to obtain modified talc powder.
[0009] More preferably, the raw materials for the methyldiallyl silane contain, by weight, 2.5-3 parts magnesium shavings, 8-10 parts allyl chloride, and 4-6 parts methyldichlorosilane; the raw materials for the organosilicon polymer coupling agent contain, by weight, 4-6 parts methyldiallyl silane, 22-26 parts n-hexane, 0.04-0.06 parts Karstedt catalyst, 2-4 parts vinyl silicone oil, and 10-14 parts triethoxysilane; and the raw materials for the modified talc powder contain, by weight, talc powder to organosilicon polymer coupling agent in a mass ratio of 10:(1-1.5).
[0010] A more optimized method for preparing the modified silica is as follows: Step 1: Under a nitrogen atmosphere, 4-methyl-2-pyridinephenol is added to tetrahydrofuran and stirred until homogeneous. Then, 3-triethoxysilylpropyl isocyanate and dibutyltin dilaurate are added sequentially, stirred for 1-3 hours, and dried to obtain a pyridylsilane coupling agent. Step 2: Silica is added to an ethanol aqueous solution, the pH is adjusted to 4-6, stirred, and then the pyridylsilane coupling agent and vinylsilane coupling agent are added. The mixture is stirred for 1-3 hours, centrifuged, washed with water, and vacuum dried to obtain the modified silica.
[0011] In a more optimized manner, the raw materials for the pyridylsilane coupling agent, by weight, are: 4-6 parts of 4-methyl-2-pyridinol, 80-100 parts of tetrahydrofuran, 10-15 parts of 3-triethoxysilylpropyl isocyanate, and 0.2-0.4 parts of dibutyltin dilaurate; the raw materials for the modified silica have a mass ratio of silica, pyridylsilane coupling agent, and vinylsilane coupling agent of 10:(0.3-0.4):(0.2-0.6).
[0012] More preferably, the accelerator includes one or more of N-cyclohexyl-2-benzothiazole sulfenamide, dibenzothiazole disulfide, and tetramethylthiuram disulfide.
[0013] More preferably, the antioxidant includes one or more of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, N-isopropyl-N'-phenyl-p-phenylenediamine, and 2-mercaptobenzimidazole.
[0014] An aging-resistant rubber sealing material for oilfield drilling and its preparation method include the following steps: Step 1: Hydrogenated nitrile rubber, EPDM rubber, reinforcing agent, accelerator, antioxidant, and stearic acid are put into a mixer and mixed at 90~110℃ for 10~20 minutes to obtain a masterbatch; Step 2: The masterbatch is put into a two-roll mill, a vulcanizing agent is added and mixed, and then the mixture is sequentially passed through a thin sheet, sheeted, and vulcanized. The finished product is then removed, and the edge material is removed to obtain the aging-resistant rubber sealing material.
[0015] In a more optimized manner, during step 2, the vulcanization process is carried out at a temperature of 150~170℃, a pressure of 10~15MPa, and a time of 3~6 minutes.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention introduces talc powder and silica with different structures in specific proportions as reinforcing agents to synergistically improve the oil resistance and aging resistance of rubber sealing materials. Furthermore, since the different morphologies of talc powder and silica lead to different dispersibility in rubber sealing materials, different macromolecular silane coupling agents (organosilicon polymer coupling agents) and small molecule silane coupling agents (pyridyl silane coupling agents) are selected to promote the uniform dispersion of the two in the rubber material, thereby optimizing and improving the oil resistance and aging resistance of the rubber material.
[0017] Talc powder has a layered structure, which has poor dispersibility compared to particle-structured fillers. Therefore, a specific organosilicon polymer coupling agent is introduced to modify it, thereby significantly improving the interfacial compatibility between talc powder and the rubber matrix. This allows the talc powder to peel off and disperse in the rubber matrix, effectively blocking the oxygen penetration path and thus delaying the oxidative aging of the rubber. At the same time, the diffusion path of oil molecules is extended, which can also reduce the amount of oil molecules penetrating and the degree of swelling. In addition, the organosilicon polymer coupling agent contains multiple vinyl groups on its molecular chain, which can participate in the vulcanization reaction of the rubber and form a chemical crosslink between the talc powder and the rubber. This crosslinked structure is more stable than simple physical adsorption, thereby improving the aging resistance of the rubber material.
[0018] Among them, silica has a particle structure, and its dispersibility is better than that of talc with a layered structure. Therefore, this application uses pyridylsilane coupling agent for modification. Since pyridylsilane coupling agent contains a highly polar pyridine ring and urethane group, it can form stable chemical bonds with the surface of silica, so that the surface is covered with hydrophobic organic groups, thereby improving the oil resistance of the material. At the same time, the nitrogen atom on the pyridine ring can interact with the active hydrogen in the rubber molecular chain, enhancing the interfacial interaction. Its rigid structure can also form a dense coating layer on the filler surface, blocking the direct contact of oil molecules and enhancing the aging resistance of rubber. In addition, a small amount of vinylsilane coupling agent is introduced to synergistically improve the dispersibility of silica in rubber, reduce the gaps between rubber molecular chains, reduce the penetration channels of oil molecules, and avoid excessive swelling of rubber. The synergistic effect of the two makes the rubber sealing material have good oil resistance and anti-aging properties. Detailed Implementation
[0019] 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.
[0020] In the following embodiments, the parts are by weight; it should be noted that there are no special restrictions on the manufacturers of the raw materials involved in this invention, and they include, exemplarily, allyl chloride (CAS: 107-05-1), methyldichlorosilane (CAS: 1066-35-9), tetrahydrofuran (CAS: 109-99-9), n-hexane (CAS: 110-54-3), vinyl silicone oil (model V-500, provided by Jiangsu Kexing Materials Co., Ltd.), triethoxysilane (CAS: 919-30-2), talc (particle size 5μm), 4-methyl-2-pyridinephenol (CAS: 603-41-8), 3-triethoxysilylpropyl isocyanate (CAS: 24801-88-5), dibutyltin dilaurate (CAS: 77-58-7), silica (particle size 20nm), vinyltriethoxysilane (CAS: 754-05-2), N-cyclohexyl-2-benzothiazole sulfenamide (CAS: 95-33-0), 2,2,4-trimethyl-1,2-dihydroquinoline polymer (CAS: 26780-96-1), stearic acid (CAS: 57-11-4), sulfur (CAS: 7704-34-9).
[0021] Pre-preparation: I. Preparation of modified talc: Step 1: (1) Add 3 parts magnesium shavings, 9 parts allyl chloride, and 5 parts methyldichlorosilane to 100 parts tetrahydrofuran, heat to 60°C, stir for 2.5 hours, extract, dry, and rotary evaporate to obtain methylhydrodiallylsilane; (2) Mix 5 parts methylhydrodiallylsilane and 24 parts n-hexane, add 0.05 parts Karstedt catalyst, set the temperature to 75°C and stir for 8 hours, rotary evaporate, add 3 parts vinyl silicone oil and 12 parts triethoxysilane, stir and react at 70°C for 8 hours, rotary evaporate to obtain organosilicon polymer coupling agent; Step 2: Add 10 parts talc to 200 parts of 80% ethanol aqueous solution, adjust the pH value to 5.5, stir evenly, then add 1.3 parts organosilicon polymer coupling agent, stir for 2 hours, centrifuge, wash with water, and vacuum dry to obtain modified talc.
[0022] II. Preparation of modified silica: Step 1: Under a nitrogen atmosphere, add 5 parts of 4-methyl-2-pyridinephenol to 100 parts of tetrahydrofuran and stir until homogeneous. Then, add 12 parts of 3-triethoxysilylpropyl isocyanate and 0.3 parts of dibutyltin dilaurate in sequence. Stir for 2 hours and dry to obtain pyridylsilane coupling agent. Step 2: Add 10 parts of silica to 200 parts of 80% ethanol aqueous solution, adjust the pH to 5, stir, then add 0.4 parts of pyridylsilane coupling agent and 0.4 parts of vinyltriethoxysilane. Stir for 2 hours, centrifuge, wash with water, and vacuum dry to obtain modified silica.
[0023] Example 1: An aging-resistant rubber sealing material for oilfield drilling and its preparation method, the specific steps are as follows: Step 1: 50 parts of hydrogenated nitrile rubber, 15 parts of EPDM rubber, 35 parts of reinforcing agent (composed of modified talc powder and modified silica in a mass ratio of 6.2:2.7), 2 parts of accelerator (N-cyclohexyl-2-benzothiazole sulfenamide), 1.5 parts of antioxidant (2,2,4-trimethyl-1,2-dihydroquinoline polymer), and 0.8 parts of stearic acid are put into a mixer and mixed at 100°C for 15 minutes to obtain a masterbatch; Step 2: The masterbatch is put into a two-roll mill, 3 parts of vulcanizing agent (sulfur) are added and mixed, and then the mixture is sequentially passed through a thin mill and sheeted out, with the temperature set at 160°C, the pressure at 13MPa, and vulcanized for 4.5 minutes. Then the product is taken out, the edge material is removed, and the aging-resistant rubber sealing material is obtained.
[0024] Example 2: An aging-resistant rubber sealing material for oilfield drilling and its preparation method, the specific steps are as follows: Step 1: 40 parts of hydrogenated nitrile rubber, 10 parts of EPDM rubber, 30 parts of reinforcing agent (composed of modified talc powder and modified silica in a mass ratio of 5.5:2.5), 1.5 parts of accelerator (N-cyclohexyl-2-benzothiazole sulfenamide), 1 part of antioxidant (2,2,4-trimethyl-1,2-dihydroquinoline polymer), and 0.5 parts of stearic acid are put into a mixer and mixed at 90°C for 10 minutes to obtain a masterbatch; Step 2: The masterbatch is put into an open mill, 2 parts of vulcanizing agent (sulfur) are added and mixed, and then the mixture is sequentially passed through a thin mill and sheeted out. The temperature is set at 150°C, the pressure at 10MPa, and the vulcanization is carried out for 3 minutes. Then the product is taken out, the edge material is removed, and the aging-resistant rubber sealing material is obtained.
[0025] Example 3: An aging-resistant rubber sealing material for oilfield drilling and its preparation method, the specific steps are as follows: Step 1: 60 parts of hydrogenated nitrile rubber, 20 parts of EPDM rubber, 40 parts of reinforcing agent (composed of modified talc powder and modified silica in a mass ratio of 7:3), 2.5 parts of accelerator (N-cyclohexyl-2-benzothiazole sulfenamide), 2 parts of antioxidant (2,2,4-trimethyl-1,2-dihydroquinoline polymer), and 1 part of stearic acid are put into a mixer and mixed at 110°C for 20 minutes to obtain a masterbatch; Step 2: The masterbatch is put into a two-roll mill, 4 parts of vulcanizing agent (sulfur) are added and mixed, and then the mixture is sequentially passed through a thin mill and sheeted out. The temperature is set at 170°C, the pressure at 15MPa, and the vulcanization time is 6 minutes. Then the product is taken out, the edge material is removed, and the aging-resistant rubber sealing material is obtained.
[0026] Comparative Example 1: Based on Example 1, the reinforcing agent components were adjusted, and the modified talc powder was replaced with ordinary talc powder. The rest remained the same as in Example 1. The specific steps are as follows: Step 1: 50 parts hydrogenated nitrile rubber, 15 parts EPDM rubber, 35 parts reinforcing agent (composed of ordinary talc powder and modified silica in a mass ratio of 6.2:2.7), 2 parts accelerator (N-cyclohexyl-2-benzothiazole sulfenamide), 1.5 parts antioxidant (2,2,4-trimethyl-1,2-dihydroquinoline polymer), and 0.8 parts stearic acid were added to a mixer and mixed at 100°C for 15 minutes to obtain the masterbatch; Step 2: The masterbatch was added to a two-roll mill, and 3 parts vulcanizing agent (sulfur) were added and mixed. Then, the mixture was sequentially passed through a thin mill and sheeted out. The temperature was set at 160°C, the pressure at 13MPa, and the vulcanization time was 4.5 minutes. The product was then removed, the edge material was removed, and the aging-resistant rubber sealing material was obtained.
[0027] Comparative Example 2: Based on Example 1, the reinforcing agent composition was adjusted, and the modified silica was replaced with ordinary silica. The rest remained the same as in Example 1. The specific steps are as follows: Step 1: 50 parts of hydrogenated nitrile rubber, 15 parts of EPDM rubber, 35 parts of reinforcing agent (composed of modified talc and ordinary silica in a mass ratio of 6.2:2.7), 2 parts of accelerator (N-cyclohexyl-2-benzothiazole sulfenamide), 1.5 parts of antioxidant (2,2,4-trimethyl-1,2-dihydroquinoline polymer), and 0.8 parts of stearic acid were added to a mixer and mixed at 100°C for 15 minutes to obtain the masterbatch; Step 2: The masterbatch was added to a two-roll mill, and 3 parts of vulcanizing agent (sulfur) were added and mixed. Then, the mixture was sequentially passed through a thin mill and sheeted out. The temperature was set at 160°C, the pressure at 13MPa, and the vulcanization time was 4.5 minutes. The product was then removed, the edge material was removed, and the aging-resistant rubber sealing material was obtained.
[0028] Comparative Example 3: Based on Example 1, both talc and silica were modified with vinyltriethoxysilane, and the rest remained the same as in Example 1. The specific steps are as follows: 1. Preparation of modified talc: 10 parts of talc were added to 200 parts of 80% ethanol aqueous solution, the pH was adjusted to 5.5, and the mixture was stirred evenly. Then, 1.3 parts of vinyltriethoxysilane were added, and the mixture was stirred for 2 hours. The mixture was then centrifuged, washed with water, and vacuum dried to obtain modified talc.
[0029] II. Preparation of modified silica: Add 10 parts of silica to 200 parts of 80% ethanol aqueous solution, adjust the pH to 5, stir, then add 0.8 parts of vinyltriethoxysilane, stir for 2 hours, centrifuge, wash with water, and vacuum dry to obtain modified silica.
[0030] III. Preparation of aging-resistant rubber sealing material: Step 1: Add 50 parts of hydrogenated nitrile rubber, 15 parts of EPDM rubber, 35 parts of reinforcing agent (composed of ordinary talc powder and ordinary silica in a mass ratio of 6.2:2.7), 2 parts of accelerator (N-cyclohexyl-2-benzothiazole sulfenamide), 1.5 parts of antioxidant (2,2,4-trimethyl-1,2-dihydroquinoline polymer), and 0.8 parts of stearic acid to a mixer and mix at 100°C for 15 minutes to obtain masterbatch; Step 2: Add the masterbatch to a two-roll mill, add 3 parts of vulcanizing agent (sulfur) and mix, then sequentially pass through a thin sheet and extrude the product. Set the temperature to 160°C, the pressure to 13MPa, and vulcanize for 4.5 minutes. Then remove the product, remove the edge material, and obtain the aging-resistant rubber sealing material.
[0031] Comparative Example 4: Based on Example 1, the ratio of reinforcing agent components was adjusted, and modified silica and modified talc were added in a mass ratio of 2.7:6.2. The rest remained the same as in Example 1. The specific steps are as follows: Step 1: 50 parts hydrogenated nitrile rubber, 15 parts EPDM rubber, 35 parts reinforcing agent (composed of modified silica and modified talc in a mass ratio of 6.2:2.7), 2 parts accelerator (N-cyclohexyl-2-benzothiazole sulfenamide), 1... 1.5 parts of antioxidant (2,2,4-trimethyl-1,2-dihydroquinoline polymer) and 0.8 parts of stearic acid are added to a mixer and mixed at 100°C for 15 minutes to obtain masterbatch; Step 2: The masterbatch is added to a two-roll mill, 3 parts of vulcanizing agent (sulfur) are added and mixed, and then the mixture is sequentially passed through a thin sheet and sheeted. The temperature is set at 160°C, the pressure at 13MPa, and the vulcanization time is 4.5 minutes. Then the product is taken out, the edge material is removed, and the aging-resistant rubber sealing material is obtained.
[0032] Performance testing: The aging-resistant rubber sealing materials prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to the following performance tests: (1) Aging resistance test: According to GB / T3512-2014 "Accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber in hot air", the temperature was set to 150℃, the aging treatment was carried out for 100 hours, and then the tensile strength of the sample was tested.
[0033] (2) Oil resistance test: According to GB / T1690-2010 "Test method for resistance to liquid of vulcanized rubber or thermoplastic rubber", the oil is selected as a mixture of toluene and isooctane with a mass ratio of 3:7. The temperature is set at 23℃, and the sample is soaked for 168 hours. Then the mass change rate and tensile strength of the sample are tested.
[0034]
[0035] Conclusion: According to the data in the table, the aging-resistant rubber sealing materials prepared in Examples 1-3 have good aging resistance and oil resistance. Comparing the performance test data of Example 1 with Comparative Examples 1-4, it can be seen that in Comparative Example 1, after replacing the modified talc with ordinary talc, the layered structure of ordinary talc could not be effectively peeled and dispersed in the rubber matrix, thus losing its barrier ability and shortening the penetration path of oxygen and oil molecules. Therefore, the aging resistance and oil resistance of the rubber material decreased. In Comparative Example 2, when the modified silica was replaced with unmodified ordinary silica, due to the poor compatibility between the silanol groups on the surface of ordinary silica and the rubber matrix, not only did it generate agglomeration in the rubber matrix, leading to stress concentration, but it also could not form an effective interfacial interaction with the rubber through the pyridine groups. This leads to an increase in the mass change rate of the rubber material and a decrease in its oil resistance and tensile strength. In Comparative Example 3, when talc and silica modified with the same vinyltriethoxysilane were used, the mechanical interlocking and chemical bonding strength of the interface layer between the talc / silicone and the rubber matrix was insufficient. Under heat, oil, or stress, the interface easily became a weak point, leading to failure, thus reducing the aging and oil resistance of the rubber material. In Comparative Example 4, when the mass ratio of modified talc to modified silica was adjusted, and silica was used as the main filler, although its dispersibility was good after modification, the lack of sufficient layered talc to construct a lamellar barrier structure prevented the effective extension of the penetration path, resulting in a rapid increase in the mass change rate of the rubber material and a decrease in its aging resistance. In conclusion, by introducing fillers of different forms to synergistically enhance the oil and aging resistance of the rubber material, and by selecting appropriate silane coupling agents to modify the fillers according to their different forms to improve their dispersibility, their contribution to the aging and oil resistance of the rubber material can be effectively improved.
[0036] 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. An aging-resistant rubber sealing material for oilfield drilling, characterized in that: The raw materials of the aging-resistant rubber sealing material, by weight, are: 40-60 parts hydrogenated nitrile rubber, 10-20 parts EPDM rubber, 30-40 parts reinforcing agent, 2-4 parts vulcanizing agent, 1.5-2.5 parts accelerator, 1-2 parts antioxidant, and 0.5-1 part stearic acid.
2. The aging-resistant rubber sealing material for oilfield drilling according to claim 1, characterized in that: The reinforcing agent is composed of modified talc and modified silica in a mass ratio of (5.5~7):(2.5~3).
3. The aging-resistant rubber sealing material for oilfield drilling according to claim 2, characterized in that: The preparation method of the modified talc is as follows: Step 1: (1) Magnesium shavings, allyl chloride and methyl dichlorosilane are added to tetrahydrofuran in sequence, heated to 55~65℃, stirred for 2~3 hours, extracted, dried and rotary evaporated to obtain methyl hydrogen diallyl silane; (2) Methyl hydrogen diallyl silane and n-hexane are mixed and Karstedt catalyst is added. The temperature is set at 70~80℃ and stirred for 7~9 hours. After rotary evaporation, vinyl silicone oil and triethoxysilane are added in sequence. The reaction is stirred at 65~75℃ for 7~9 hours and rotary evaporated to obtain organosilicon polymer coupling agent; Step 2: Talc powder is added to ethanol aqueous solution, the pH value is adjusted to 5~6, stirred evenly, and then organosilicon polymer coupling agent is added. The mixture is stirred for 1~3 hours, centrifuged, washed with water and vacuum dried to obtain modified talc powder.
4. The aging-resistant rubber sealing material for oilfield drilling according to claim 3, characterized in that: The raw materials for the methyldiallyl silane, by weight, consist of: 2.5-3 parts magnesium shavings, 8-10 parts allyl chloride, and 4-6 parts methyldichlorosilane; the raw materials for the organosilicon polymer coupling agent, by weight, consist of: 4-6 parts methyldiallyl silane, 22-26 parts n-hexane, 0.04-0.06 parts Karstedt catalyst, 2-4 parts vinyl silicone oil, and 10-14 parts triethoxysilane; the raw materials for the modified talc have a talc to organosilicon polymer coupling agent mass ratio of 10:(1-1.5).
5. The aging-resistant rubber sealing material for oilfield drilling according to claim 2, characterized in that: The modified silica is prepared as follows: Step 1: Under a nitrogen atmosphere, 4-methyl-2-pyridinephenol is added to tetrahydrofuran and stirred until homogeneous. Then, 3-triethoxysilylpropyl isocyanate and dibutyltin dilaurate are added sequentially. The mixture is stirred for 1-3 hours and dried to obtain pyridylsilane coupling agent. Step 2: Silica is added to an ethanol aqueous solution, the pH is adjusted to 4-6, and stirred. Then, pyridylsilane coupling agent and vinylsilane coupling agent are added and stirred for 1-3 hours. The mixture is centrifuged, washed with water, and vacuum dried to obtain modified silica.
6. The aging-resistant rubber sealing material for oilfield drilling according to claim 5, characterized in that: The raw materials for the pyridylsilane coupling agent, by weight, are: 4-6 parts of 4-methyl-2-pyridinol, 80-100 parts of tetrahydrofuran, 10-15 parts of 3-triethoxysilylpropyl isocyanate, and 0.2-0.4 parts of dibutyltin dilaurate; the raw materials for the modified silica have a mass ratio of silica, pyridylsilane coupling agent, and vinylsilane coupling agent of 10:(0.3-0.4):(0.2-0.6).
7. The aging-resistant rubber sealing material for oilfield drilling according to claim 1, characterized in that: The accelerator includes one or more of N-cyclohexyl-2-benzothiazole sulfenamide, dibenzothiazole disulfide, and tetramethylthiuram disulfide.
8. The aging-resistant rubber sealing material for oilfield drilling according to claim 1, characterized in that: The antioxidant includes one or more of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, N-isopropyl-N'-phenyl-p-phenylenediamine, and 2-mercaptobenzimidazole.
9. The aging-resistant rubber sealing material for oilfield drilling and its preparation method according to claim 1, characterized in that: The process includes the following steps: Step 1: Hydrogenated nitrile rubber, EPDM rubber, reinforcing agent, accelerator, antioxidant, and stearic acid are put into a mixer and mixed at 90~110℃ for 10~20 minutes to obtain masterbatch; Step 2: The masterbatch is put into a two-roll mill, vulcanizing agent is added and mixed, and then the mixture is sequentially passed through a thin mill, sheeted, and vulcanized. The finished product is then removed, the edge material is removed, and the aging-resistant rubber sealing material is obtained.
10. The aging-resistant rubber sealing material for oilfield drilling and its preparation method according to claim 9, characterized in that: In step 2, the vulcanization process is carried out at a temperature of 150-170°C, a pressure of 10-15 MPa, and a time of 3-6 minutes.