A high temperature resistant antioxidant, hnbr composition, and preparation method and application thereof

Abstract

The application provides a high-temperature-resistant antioxidant, an HNBR composition, a preparation method and application thereof, and belongs to the field of rubber antioxidants. The antioxidant comprises a complex system of a macromolecular antioxidant represented by formula (A) and a small-molecule amine antioxidant, and through synergistic effect, the migration resistance, thermal stability and long-acting antioxidant capacity of the antioxidant are significantly improved. When applied to HNBR, the HNBR can maintain excellent mechanical property stability under long-term high-temperature aging conditions, and the temperature resistance limit of traditional HNBR materials is effectively broken. The technology is particularly suitable for the field of rubber products with high requirements for heat resistance and durability. Formula (A).

Description

Technical Field

[0001] This invention belongs to the field of rubber antioxidants, specifically relating to a high-temperature resistant antioxidant, an HNBR composition, its preparation method, and its application. Background Technology

[0002] Hydrogenated nitrile butadiene rubber (HNBR) is a highly saturated specialty elastomer produced by selectively hydrogenating the unsaturated double bonds of butadiene units in nitrile butadiene rubber (NBR), reducing them to saturated carbon-carbon single bonds while retaining the acrylonitrile unit structure. Compared to NBR, HNBR not only maintains excellent oil resistance and abrasion resistance, but also exhibits significantly improved heat resistance, chemical resistance (such as good resistance to hydrogen sulfide), oxidation resistance, ozone resistance, aging resistance, radiation resistance, and good dynamic performance, making it a specialty rubber material with outstanding comprehensive performance. In critical components such as automotive engine oil seals, the combustion temperature inside the cylinder can reach 800~1000℃ during engine operation. After cooling by the cylinder block, the temperature around the crankcase usually remains in the range of 120~150℃. Under high-load conditions, such as rapid acceleration, climbing, or prolonged high-speed driving, the engine cooling pressure increases, which may cause the temperature in local areas such as the front and rear ends of the crankshaft and the camshaft end to rise further to around 180℃. However, the high-temperature resistance of HNBR materials is still facing severe challenges. Their conventional temperature range (150℃ for long-term use and 180℃ for short-term use) is no longer sufficient to meet the needs of automotive engine oil seals under increasingly harsh operating conditions. Therefore, developing HNBR that can withstand higher temperatures (>150℃) for a long time has become an urgent technical problem to be solved.

[0003] Adding antioxidants is a conventional and important technique for improving the heat resistance and anti-aging properties of rubber materials. Currently, hindered phenolic and aromatic amine antioxidants are the two most widely used types of antioxidants due to their excellent antioxidant properties. However, these two types of antioxidants are mostly small molecule compounds, which have significant drawbacks such as easy volatility, easy migration, and poor solvent extraction resistance under harsh environments such as high temperature and oil media. They are easily lost from the rubber matrix and cannot exert a stable anti-aging effect for a long time, which seriously limits their application in HNBR products that require long-term high temperature resistance. To address the above-mentioned shortcomings of small molecule antioxidants, grafting or bonding active groups to macromolecules to prepare migration-resistant and low-volatility macromolecular antioxidants has become an important research direction.

[0004] Existing technologies include research on the application of macromolecular antioxidants. The literature (Fan Xuan. Synthesis and Performance Study of Novel Migration-Resistant Macromolecular Antioxidant [D]. Beijing University of Chemical Technology) discloses the synthesis and performance study of a novel migration-resistant macromolecular antioxidant. Specifically, a macromolecular antioxidant was prepared using a styrene-maleic anhydride copolymer as a carrier. This macromolecular antioxidant can reduce the rate of change in tensile strength, elongation at break, and hardness of styrene-butadiene rubber / carbon black composites after 7 days of aging (100℃, 168h). However, the paper does not provide any indication that this macromolecular antioxidant can be used in hydrogenated nitrile butadiene rubber (HNBR) for long-term aging at 180℃ for 336h. Patent application CN113185779A discloses a high-temperature and wear-resistant rubber composite material made from a blend of ethylene propylene diene monomer (EPDM) rubber, chlorinated polyethylene rubber (CM), and HNBR. By incorporating a high-temperature and wear-resistant reinforcing composite agent containing aramid pulp, thermoplastic phenolic resin, micronized nano-ceramic aluminum alloy, and silane coupling agent KH550, the resulting HNBR compound maintains a relatively stable range in terms of tensile strength and elongation at break after aging at 180°C for 96 hours. Another patent application, CN108102179A, reports a system using hydrogenated nitrile butadiene rubber as a base material and various rubber additives in specific proportions. This system enables the HNBR compound to maintain good mechanical properties and stability after hot air aging at 150°C for 72 hours, while also possessing advantages such as high strength, high elasticity, aging resistance, and flame retardancy. Nevertheless, the aforementioned existing technical solutions still have limitations: most of them can only guarantee long-term use of HNBR at 150℃ or meet short-term heat resistance requirements at 180℃, and cannot achieve long-term stable use at higher temperatures (>150℃), thus failing to fully meet the stringent safety and durability requirements of automotive engine oil seals in continuous high-temperature environments.

[0005] Therefore, developing a high-temperature resistant HNBR material that can maintain stable performance over a long period of time in environments above 150℃ remains a pressing technical challenge that needs to be overcome in this field. Summary of the Invention

[0006] To overcome the problems of conventional antioxidants in existing technologies, such as easy volatility and migration at high temperatures and poor solvent extraction resistance, which lead to insufficient anti-aging performance of special rubbers such as hydrogenated nitrile butadiene rubber (HNBR) under harsh long-term high-temperature (e.g., 180°C) conditions, this invention aims to provide a compound antioxidant and its composition and application that combine excellent heat resistance, oxidation resistance, and migration resistance. Specifically, this invention provides a rubber antioxidant composition comprising a specific macromolecular antioxidant (as shown in formula (A)) and a small-molecule amine antioxidant used in synergy. This composition can not only significantly improve the antioxidant aging resistance and thermal stability of the rubber matrix (especially HNBR) under long-term high-temperature (e.g., 180°C) conditions, but also effectively overcome the defects of rapid degradation and poor durability of single small-molecule antioxidants, thereby meeting the performance requirements of key components such as automotive engine oil seals for long-term stable operation under extreme high-temperature environments.

[0007] The specific technical solution is as follows: This invention provides a rubber antioxidant, which is shown in formula (A): Formula (A) Where m+n=40~100.

[0008] Furthermore, the number-average molecular weight (Mn) of the rubber antioxidant is 4600 g / mol to 11600 g / mol.

[0009] The present invention also provides a method for preparing the above-mentioned rubber antioxidant, the method comprising the following steps: Under an inert atmosphere, maleic anhydride and vinyl aromatic monomers are mixed and reacted with an organic solution containing a free radical initiator to obtain a maleic anhydride-vinyl aromatic copolymer; the maleic anhydride-vinyl aromatic copolymer is further reacted with an aromatic primary amine to obtain the rubber antioxidant shown in formula (A).

[0010] Further, the vinyl aromatic monomer is styrene; the free radical initiator is azobisisobutyronitrile (AIBN); the organic solvent is toluene; the mass ratio of maleic anhydride, vinyl aromatic monomer, and free radical initiator is 18~22:20~25:0.3~0.6; the reaction temperature is 60~80℃, and the reaction time is 2~6 hours; the mass ratio of maleic anhydride-vinyl aromatic copolymer to aromatic primary amine is 0.5~2:0.5~2; the aromatic primary amine is aniline; and the temperature for further reaction is 120~130℃.

[0011] The present invention also provides a rubber antioxidant composition comprising the following components in parts by weight: 40-90 parts of the above-mentioned rubber antioxidant and 10-60 parts of a small molecule amine antioxidant.

[0012] Furthermore, the rubber antioxidant composition comprises the following components in parts by weight: 50-80 parts of the above-mentioned rubber antioxidant and 20-50 parts of small molecule amine antioxidant.

[0013] The present invention also provides a hydrogenated nitrile butadiene rubber composition vulcanizate, which is prepared from raw materials comprising the following parts by weight: 100 parts of hydrogenated nitrile butadiene rubber, 30-50 parts of reinforcing filler, 3-8 parts of vulcanization auxiliaries, 3-8 parts of vulcanization activators, 1-5 parts of the above-mentioned rubber antioxidant composition, 2-5 parts of crosslinking agent, 2-6 parts of organic peroxide vulcanizing agent, 1-5 parts of secondary antioxidant, and 2-5 parts of plasticizer.

[0014] Furthermore, the hydrogenated nitrile rubber composition vulcanizate is prepared from raw materials comprising the following parts by weight: 100 parts hydrogenated nitrile rubber, 50 parts reinforcing filler, 5 parts vulcanization accelerator, 5 parts vulcanization activator, 3 parts of the above-mentioned rubber antioxidant composition, 2 parts crosslinking agent, 4 parts organic peroxide vulcanizing agent, 1 part secondary antioxidant, and 5 parts plasticizer.

[0015] Furthermore, the hydrogenated nitrile rubber composition vulcanizate is also prepared from raw materials comprising the following parts by weight: 3-5 parts of nano-reinforcing filler and 3-6 parts of activator.

[0016] Further, the reinforcing filler is carbon black; the vulcanizing aid is zinc oxide; the vulcanizing activator is stearic acid; the crosslinking agent is triallyl isocyanurate; the organic peroxide vulcanizing agent is dicumyl peroxide; the plasticizer is trioctyl trimellitate (TOTM); the secondary antioxidant is 2-mercaptobenzimidazole; the nano-reinforcing filler is multi-walled carbon nanotubes; and the activating agent is magnesium oxide.

[0017] Furthermore, the carbon black is carbon black N330; the nano-reinforcing filler is multi-walled carbon nanotubes; and the magnesium oxide is magnesium oxide Kyowamag MF-150.

[0018] The present invention also provides a method for preparing the above-mentioned hydrogenated nitrile butadiene rubber composition vulcanizate, the method comprising the following steps: adding each raw material into a mixing equipment and mixing them evenly to form a compound; subjecting the compound to a first-stage vulcanization and a second-stage vulcanization treatment to obtain the hydrogenated nitrile butadiene rubber composition vulcanizate.

[0019] Further, the method includes the following steps: first, adding hydrogenated nitrile rubber to a mixing equipment and mixing it evenly; then adding other raw materials except for reinforcing fillers; and finally adding reinforcing fillers and mixing them evenly to prepare a compound. The temperature of the first stage of vulcanization is 140℃~160℃; the temperature of the second stage of vulcanization is 140℃~190℃, and the time is 2h~9h.

[0020] Furthermore, the temperature of the first stage of vulcanization is 150°C; the temperature of the second stage of vulcanization is 150°C to 180°C, and the time is 3 hours to 8 hours.

[0021] The present invention also provides the use of the above-mentioned rubber antioxidant, the above-mentioned rubber antioxidant composition, and the above-mentioned hydrogenated nitrile rubber composition vulcanizate in the preparation of high-temperature resistant rubber products.

[0022] Compared with the prior art, the present invention has achieved the following beneficial effects: (1) Significantly improves long-term high-temperature aging stability: Although the literature (Fan Xuan. Synthesis and performance study of novel migration-resistant macromolecular antioxidants [D]. Beijing University of Chemical Technology) has disclosed that macromolecular antioxidants with similar structures can improve aging performance in styrene-butadiene rubber / carbon black composites, the antioxidant composition provided by this invention can significantly reduce the rate of change of tensile strength, elongation at break and hardness of hydrogenated nitrile butadiene rubber (HNBR) vulcanizate under more stringent conditions (180℃, 336h long-term hot air aging), showing superior high-temperature durability.

[0023] (2) Achieving synergistic antioxidant effect: By scientifically combining a macromolecular antioxidant with a specific structure (as shown in formula (A)) with a small molecule amine antioxidant, the two produce a synergistic effect in the rubber system. Compared with the use of modified macromolecular antioxidants or small molecule amine antioxidants alone, this composition further improves the overall antioxidant performance, thereby more effectively inhibiting the oxidative degradation of rubber at high temperatures.

[0024] (3) Meets the application requirements under extreme working conditions: After the antioxidant composition is applied to the HNBR matrix and vulcanized, the resulting vulcanized rubber can still maintain excellent mechanical property stability under simulated extreme operating environment of automobile engine (long-term high temperature of 180℃), ensuring that the automobile engine oil seal prepared by it can operate reliably for a long time under high load and high temperature conditions, solving the technical problem that the existing antioxidants have rapid degradation of protective performance and insufficient durability under long-term high temperature of 180℃.

[0025] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention.

[0026] The following detailed embodiments further illustrate the above-described content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following embodiments. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention. Attached Figure Description

[0027] Figure 1 The image shows the infrared spectrum of the macromolecular antioxidant of formula (A). Detailed Implementation

[0028] The raw materials and equipment used in this invention are all known products, obtained by purchasing commercially available products.

[0029] In the formulation of the specific embodiments of the present invention, "1 part (1phr)" means 1g / 100g raw rubber.

[0030] Example 1: Preparation of macromolecular antioxidant of formula (A) Synthesis steps: Under nitrogen atmosphere, a condenser and constant pressure titration funnel were set up in a round-bottom three-necked flask. Maleic anhydride (19.6 g) and styrene (22.9 g) were added and stirred until dissolved. Nitrogen gas was then introduced, and the temperature was raised to 70 °C after 10 min. Then, azobisisobutyronitrile (AIBN) (0.45 g) and toluene solution (100 mL) were added dropwise, and the reaction was carried out at this temperature for 4 h. During the reaction, a white precipitate gradually precipitated. After the reaction was completed, the mixture was filtered, and the filter cake was soaked in methanol (50 mL) several times to obtain the maleic anhydride-styrene copolymer (yield 96%). (Since this temperature is an alternating copolymerization, the monomer units of styrene (St) and maleic anhydride (MAH) will be connected alternately, m:n≈1:1. The number-average molecular weight (Mn: 4600g / mol~11600g / mol) was measured by gel permeation chromatography (GPC). The structural molecular weights of the repeating units of the maleic anhydride-styrene copolymer are 119.19g / mol and 113.09g / mol, respectively. Then, according to the formula, m≈n=Mn / (119.19+113.09) can be calculated.)

[0031] Add the product (10g) from the first step and aniline (10g) to a round-bottom three-necked flask, stir to dissolve, heat to 125°C after 10 min, and continue the reaction after stabilization. Cool the product to room temperature, filter, and wash several times to obtain a white product (yield of 85%).

[0032] The infrared spectrum of the macromolecular antioxidant of formula (A) is shown below: Figure 1 As can be seen from the infrared curve at 1600cm -1The disappearance of the double bond characteristic peak at 3462 cm⁻¹ indicates that maleic anhydride and styrene have successfully copolymerized, while the peak at 3462 cm⁻¹... -1 and 3570cm -1 The decrease in the content of the characteristic peak of phenylenediamine indicates that the antioxidant has been successfully synthesized.

[0033] Example 2: Preparation of high-temperature resistant rubber antioxidant composition and HNBR composition vulcanizate 50 parts of the macromolecular antioxidant prepared in Example 1 and 50 parts of the small molecule amine antioxidant 445 (4,4'-bis(phenylisopropyl)diphenylamine) were mixed evenly to obtain rubber antioxidant composition 1.

[0034] Take 100 parts of HNBR, 50 parts of carbon black N330, 5 parts of zinc oxide, 5 parts of stearic acid, 3 parts of rubber antioxidant composition 1, 1 part of 2-mercaptobenzimidazole, 5 parts of trioctyl trimellitate (TOTM), 2 parts of triallyl isocyanurate (TAIC), and 4 parts of dicumyl peroxide (BIBP). Mix the HNBR evenly on a two-roll mill, add the fillers except for carbon black, mix evenly, then add carbon black and mix evenly again. Let the compound stand at room temperature for 16 hours, then perform a first-stage vulcanization at 150℃. After removing the vulcanized sheet, perform a second-stage vulcanization at 150℃~180℃ for 3~8 hours to obtain a high-performance HNBR composition vulcanizate.

[0035] Example 3: Preparation of high-temperature resistant rubber antioxidant composition and HNBR composition vulcanizate 66.6 parts of the macromolecular antioxidant prepared in Example 1 and 33.4 parts of the small molecule amine antioxidant 445 were mixed evenly to obtain rubber antioxidant composition 2.

[0036] Referring to the preparation method of HNBR composition vulcanizate in Example 2, rubber antioxidant composition 1 was replaced with rubber antioxidant composition 2 to obtain the corresponding HNBR composition vulcanizate.

[0037] Example 4: Preparation of high-temperature resistant rubber antioxidant composition and HNBR composition vulcanizate 75 parts of the macromolecular antioxidant prepared in Example 1 and 25 parts of the small molecule amine antioxidant 445 were mixed evenly to obtain rubber antioxidant composition 3.

[0038] Referring to the preparation method of HNBR composition vulcanizate in Example 2, rubber antioxidant composition 1 was replaced with rubber antioxidant composition 3 to obtain the corresponding HNBR composition vulcanizate.

[0039] Example 5: Preparation of high-temperature resistant rubber antioxidant composition and HNBR composition vulcanizate 80 parts of the macromolecular antioxidant prepared in Example 1 and 20 parts of the small molecule amine antioxidant 445 were mixed evenly to obtain rubber antioxidant composition 4.

[0040] Referring to the preparation method of HNBR composition vulcanizate in Example 2, rubber antioxidant composition 1 was replaced with rubber antioxidant composition 4 to obtain the corresponding HNBR composition vulcanizate.

[0041] The following is a comparative example.

[0042] Comparative Example 1: Preparation of HNBR Composition Vulcanizate Referring to the preparation method of HNBR composition vulcanizate in Example 2, the rubber antioxidant composition 1 was replaced with macromolecular antioxidant of formula (A) to obtain the corresponding HNBR composition vulcanizate.

[0043] Comparative Example 2: Preparation of HNBR Composition Vulcanizate Referring to the preparation method of HNBR composition vulcanizate in Example 2, the rubber antioxidant composition 1 was replaced with small molecule amine antioxidant 445 to obtain the corresponding HNBR composition vulcanizate.

[0044] Comparative Example 3: Preparation of HNBR Composition Vulcanizate 80 parts of the macromolecular antioxidant prepared in Example 1 and 20 parts of the small molecule amine antioxidant 4010 (N-diisobutyl-2-phenyl-1,4-phenylenediamine) were mixed evenly to obtain rubber antioxidant composition 5.

[0045] Referring to the preparation method of HNBR composition vulcanizate in Example 2, rubber antioxidant composition 1 was replaced with rubber antioxidant composition 5 to obtain the corresponding HNBR composition vulcanizate.

[0046] The following experimental examples demonstrate the beneficial effects of the present invention.

[0047] Experiment Example 1: Testing the properties of vulcanizates of different HNBR compositions 1. Experimental Methods The HNBR composition vulcanizates prepared in Examples 2-5 and Comparative Examples 1-2 were placed in an aging chamber at 180°C for 14 days to test their performance.

[0048] 2. Experimental Results The test results are shown in Table 1.

[0049] Table 1 Properties of vulcanizates of different HNBR compositions The data in Table 1 show that, in terms of mechanical properties, the rubber antioxidant compositions of Examples 2-5 of this invention exhibit better or equivalent overall mechanical properties in HNBR vulcanizates, including initial tensile strength (26.4 MPa~29.3 MPa), elongation at break (209%~234%), and stress at 100% constant elongation. These properties are superior to or equivalent to those of Comparative Examples 1 (Formula (A) macromolecular antioxidant), 2 (small molecule amine antioxidant 445), and 3 (small molecule amine antioxidant 4010) which use only single-component antioxidants. This indicates that the rubber antioxidant compositions of this invention can maintain good initial mechanical properties in HNBR without producing negative effects.

[0050] Regarding the heat-resistant oil performance, the oil volume change rate of Examples 2-5 under 180°C*70h conditions was ≤7.8%, significantly lower than that of Comparative Example 1 (≤10.7%), Comparative Example 2 (≤8.4%), and Comparative Example 3 (≤8.0%). This fully demonstrates that the compound rubber antioxidant composition of the present invention can effectively improve the dimensional stability and swelling resistance of HNBR materials in high-temperature oil media.

[0051] Regarding long-term thermo-oxidative aging stability, after harsh hot air aging at 180°C for 336 hours, the embodiments of the present invention exhibit significant advantages in the retention rate of key performance characteristics: the absolute values ​​of the tensile strength change rate (-27% to -31%) and elongation at break change rate (-26% to -32%) of the embodiments are much lower than those of Comparative Example 1 (-43% and -42%, respectively), Comparative Example 2 (-42% and -49%, respectively), and Comparative Example 3 (-40% and -37%, respectively); the increase in hardness of the embodiments (+11.1 to +14) is comparable to that of the comparative examples, but considering that their initial mechanical property loss is smaller, the overall degree of aging is lower. The antioxidant compound system of the present invention exerts a significant synergistic antioxidant effect, which can more effectively inhibit the oxidative degradation of HNBR under long-term high temperature, thereby maintaining the stability of its mechanical properties and solving the problem of rapid decay of protective performance of single antioxidants under long-term high temperature of 180°C in the prior art.

[0052] In summary, the technical solution of this invention provides a high-temperature resistant antioxidant composition comprising a specific macromolecular antioxidant and a small-molecule amine antioxidant, and based on this, develops corresponding HNBR compositions, preparation methods, and application schemes. This effectively solves the technical problems of traditional small-molecule antioxidants being prone to volatility, migration, and insufficient protective durability at high temperatures. This composition significantly improves the heat resistance and anti-migration ability of the antioxidant system in the rubber matrix, enabling the resulting HNBR material to maintain excellent mechanical property stability even after long-term thermal aging at 180°C or even higher temperatures. This invention not only expands the reliable application range of HNBR in extreme high-temperature environments but also provides a new technical path for improving the performance of other special rubber products requiring long-term high-temperature and aging resistance.

Claims

1. A rubber antioxidant composition, characterized in that, The rubber antioxidant composition comprises the following components in parts by weight: 40-90 parts of rubber antioxidant and 10-60 parts of small molecule amine antioxidant; wherein the small molecule amine antioxidant is 4,4'-bis(phenylisopropyl)diphenylamine; The preparation method of the rubber antioxidant includes the following steps: under an inert atmosphere, maleic anhydride and vinyl aromatic monomer are mixed, and a toluene solution of a free radical initiator is added to react and obtain a maleic anhydride-vinyl aromatic copolymer; the maleic anhydride-vinyl aromatic copolymer is further reacted with an aromatic primary amine to obtain the rubber antioxidant; the vinyl aromatic monomer is styrene; the free radical initiator is azobisisobutyronitrile; the mass ratio of maleic anhydride, vinyl aromatic monomer and free radical initiator is 18~22:20~25:0.3~0.6; the reaction temperature is 60~80℃ and the time is 2~6 hours; the mass ratio of maleic anhydride-vinyl aromatic copolymer to aromatic primary amine is 0.5~2:0.5~2; the aromatic primary amine is aniline; the further reaction temperature is 120~130℃.

2. The rubber antioxidant composition according to claim 1, characterized in that, The rubber antioxidant composition comprises the following components in parts by weight: 50-80 parts of rubber antioxidant and 20-50 parts of small molecule amine antioxidant.

3. A hydrogenated nitrile butadiene rubber composition vulcanizate, characterized in that, The hydrogenated nitrile butadiene rubber composition vulcanizate is prepared from raw materials comprising the following parts by weight: 100 parts hydrogenated nitrile butadiene rubber, 30-50 parts reinforcing filler, 3-8 parts vulcanization auxiliaries, 3-8 parts vulcanization activators, 1-5 parts of the rubber antioxidant composition according to claim 1 or 2, 2-5 parts crosslinking agent, 2-6 parts organic peroxide vulcanizing agent, 1-5 parts secondary antioxidant, and 2-5 parts plasticizer; wherein the reinforcing filler is carbon black, the vulcanization auxiliaries are zinc oxide, the vulcanization activators are stearic acid, the crosslinking agent is triallyl isocyanurate, the organic peroxide vulcanizing agent is dicumyl peroxide, and the secondary antioxidant is 2-mercaptobenzimidazole.

4. The hydrogenated nitrile butadiene rubber composition vulcanizate according to claim 3, characterized in that, The hydrogenated nitrile rubber composition vulcanizate is also prepared from raw materials comprising the following parts by weight: 3-5 parts of nano-reinforcing filler and 3-6 parts of activator; wherein the nano-reinforcing filler is multi-walled carbon nanotubes and the activator is magnesium oxide.

5. The hydrogenated nitrile butadiene rubber composition vulcanizate according to claim 4, characterized in that, The plasticizer is trioctyl trimellitate.

6. A method for preparing a vulcanizate of the hydrogenated nitrile butadiene rubber composition according to any one of claims 3 to 5, characterized in that, The method includes the following steps: adding each raw material to a mixing equipment and mixing them evenly to form a compound; subjecting the compound to a first-stage vulcanization and a second-stage vulcanization treatment to obtain the hydrogenated nitrile rubber composition vulcanizate.

7. The method according to claim 6, characterized in that, The method includes the following steps: first, adding hydrogenated nitrile butadiene rubber to a mixing equipment and mixing it evenly; then adding other raw materials except for reinforcing fillers; and finally adding reinforcing fillers and mixing them evenly to prepare a compound. The temperature of the first stage of vulcanization is 140℃~160℃; the temperature of the second stage of vulcanization is 140℃~190℃, and the time is 2h~9h.

8. Use of the rubber antioxidant composition according to claim 1 or 2, or the vulcanizate of the hydrogenated nitrile butadiene rubber composition according to any one of claims 3 to 5, in the preparation of high-temperature resistant rubber products.

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