Low-temperature-resistant low-compression permanent deformation rubber material and preparation method thereof

Abstract

The invention discloses a low-temperature-resistant low-compression permanent deformation rubber material and a preparation method thereof, and belongs to the technical field of rubber materials. The composite material comprises the following components in parts by weight: 95-105 parts of hydrogenated butadiene-acrylonitrile rubber, 3-8 parts of ZnO-PB-MMT composite particles, 1-3 parts of an anti-aging agent, 70-90 parts of carbon black, 1-3 parts of an internal release agent, 1-3 parts of a dispersing agent, 4-8 parts of a peroxide crosslinking agent, 3-5 parts of a plasticizer and 1-3 parts of a cyclic olefin polymer. Wherein the composite particles solve the dispersion defect of traditional ZnO and form a multi-dimensional reinforcing network with peroxide and APL, and the rubber material provided by the invention solves the problem that the rubber material has excellent compression set performance on the premise of keeping excellent low-temperature performance; and the method can be suitable for conditions with lower temperature and more severe environment, and especially has wide application prospects in new energy products.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber materials, and particularly relates to a low-temperature resistant and low-compression permanent deformation rubber material and a preparation method thereof. Background Art

[0002] Currently, O-rings face increasingly stringent material requirements, and traditional O-ring materials face significant challenges in low-temperature resistance and compression set performance. While the widely used hydrogenated nitrile rubber (HNBR) material offers excellent oil resistance and mechanical properties at normal temperatures, it exhibits significant deficiencies in low-temperature environments: decreased molecular chain mobility causes the material to become hard and brittle, resulting in a loss of resilience. Furthermore, under long-term compressive stress, the material is susceptible to irreversible deformation, manifesting as an increase in compression set, ultimately leading to seal failure. This issue is particularly acute in dynamic sealing scenarios, directly threatening the equipment's sealing reliability and service life.

[0003] Existing O-ring sealing materials all have certain shortcomings. For example, in special or extreme environments, existing hydrogenated nitrile sealing materials have problems with low-temperature resistance and poor compression permanent deformation performance. The patent application with publication number CN119286145A discloses a low-pressure color-changing environmentally friendly O-ring terpolymer rubber and its preparation method. EPDM rubber is used as the base polymer, and a new low-temperature sealing material system is constructed by introducing hydroxypropyl methylcellulose acetate succinate and g-C3N4 / shell powder composite particles as core additives. Its formula design aims to solve the problem of low-temperature embrittlement while taking into account environmental protection needs. Although the low-temperature performance is excellent, the material has a high compression permanent deformation rate in a constant pressure environment and under a temperature cycle. During long-term use, the sealing force may decay due to plastic deformation. Therefore, the development of a low-temperature resistant and low-compression permanent deformation rubber material is of great significance to the safety of new energy products and the extension of their service life. Summary of the Invention

[0004] The object of the present invention is to provide a low-temperature resistant and low-compression permanent deformation rubber material to solve the problem that the rubber material cannot simultaneously achieve excellent compression permanent deformation performance while maintaining excellent low-temperature performance.

[0005] A second object of the present invention is to provide a method for preparing a low-temperature-resistant, low-compression permanent deformation rubber material, which is used to prepare the above-mentioned low-temperature-resistant, low-compression permanent deformation rubber material.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A low-temperature-resistant and low-compression permanent deformation rubber material comprises, by weight, 95-105 parts of hydrogenated nitrile rubber, 3-8 parts of ZnO-PB-MMT composite particles, 1-3 parts of an antioxidant, 70-90 parts of carbon black, 1-3 parts of an internal release agent, 1-3 parts of a dispersant, 4-8 parts of a peroxide crosslinking agent, 3-5 parts of a plasticizer, and 1-3 parts of a cyclic olefin polymer.

[0007] Furthermore, the ZnO-PB-MMT composite particles are prepared by the following steps: (1) Add nano ZnO to toluene and disperse it by ultrasonic to obtain a nano ZnO suspension; (2) Dissolve maleic anhydride modified polybutadiene in nano-ZnO suspension and stir under nitrogen protection; (3) Add pretreated cationic modified montmorillonite, heat to 75-80°C, high-speed shear, and rotary evaporate to obtain ZnO-PB-MMT composite particles.

[0008] Furthermore, the weight ratio of the nano ZnO, toluene, maleic anhydride modified polybutadiene and cationic modified montmorillonite is (45-60): (450-600): (25-40): (15-25).

[0009] Furthermore, the maleic anhydride-modified polybutadiene has a maleic anhydride grafting rate of 3%-5% and a number average molecular weight of 5000-8000.

[0010] Furthermore, the modifier of the cationic modified montmorillonite is one or a combination of CTAB (hexadecyltrimethylammonium bromide), DTAC (dodecyltrimethylammonium chloride) and STAB (octadecyltrimethylammonium bromide).

[0011] Furthermore, the pretreatment is to vacuum dry the montmorillonite, grind it and sieve it; the aperture of the sieve is 180-220 mesh.

[0012] Furthermore, the stirring is performed by heating the mixture to 55-60° C. and stirring for 1-1.5 hours; and the high-speed shearing is performed at a rotation speed of 3000 rpm for 2-3 hours.

[0013] Furthermore, the model of the hydrogenated nitrile rubber is Zetpol ® 4310; Zetpol in the hydrogenated nitrile rubber ® The acrylonitrile content of 4310 is 18%-20%. The main molecular chain of hydrogenated nitrile rubber with low acrylonitrile content is more flexible. It will not become brittle and hard under low temperature conditions and lose its sealing effect, and it can still maintain the good elasticity of the rubber.

[0014] Furthermore, the particle size of the carbon black is 201-500 nm, and the specific model is carbon black N990. Carbon black with a larger particle size is mixed with hydrogenated nitrile rubber with a low acrylonitrile content to improve the compression permanent set performance of the hydrogenated nitrile rubber.

[0015] Furthermore, the dispersant model is dispersant FL, which can promote the uniform dispersion of filler carbon black in the rubber compound, improve mixing efficiency and quality stability of vulcanized products, and greatly increase the fluidity of the HNBR rubber compound.

[0016] Furthermore, the antioxidant is any one or a combination of antioxidant 445, antioxidant RD and antioxidant MB.

[0017] Furthermore, the internal release agent is any one or a combination of WS280, PS206 and IOTA 257‌.

[0018] Furthermore, the plasticizer is any one or a combination of plasticizer TP-95, plasticizer TP-759 and plasticizer TP-90B.

[0019] Furthermore, the cyclic olefin polymer is APL. Cyclic olefin polymer has abundant side chains, which makes it have low anisotropy, thus ensuring the dimensional stability of the rubber material under different environments.

[0020] Furthermore, the peroxide crosslinking agent model is peroxide crosslinking agent BIB-40GS.

[0021] This invention is made by mixing low-acrylonitrile rubber with large-particle carbon black and some small-particle chemicals. It exhibits excellent low-temperature resistance and low compression set. Compared to conventional hydrogenated nitrile materials, this invention maintains its excellent rubber properties even in temperatures as cold as -40°C to -50°C. Conventional products, however, may become brittle and glass-like, losing their elasticity. Compared to conventional O-rings, this invention maintains excellent elasticity even in low-temperature environments, ensuring a secure seal.

[0022] The low acrylonitrile content raw rubber Zetpol used in the present invention ® 4310, with its flexible molecular chain structure, gives the material excellent low-temperature resistance; the coarse-particle carbon black N990 effectively improves the material's rebound performance, giving the rubber material the excellent characteristic of low compression permanent set; and the dispersant FL effectively improves the mixing uniformity of the various small ingredients in the rubber compound, especially the dispersion of carbon black particles in the rubber compound, while increasing the rubber compound's fluidity and making the rubber material's overall performance more stable.

[0023] A method for preparing a low-temperature-resistant and low-compression permanent deformation rubber material comprises the following steps: S1, first stage mixing: mixing hydrogenated nitrile rubber for 35 seconds to 40 seconds, adding internal mold release agent, dispersant, plasticizer, ZnO-PB-MMT composite particles, and antioxidant and mixing for 60 seconds to 80 seconds; then adding carbon black in batches; keeping the temperature at 88-93°C and 108-113°C for 20-25 seconds respectively, continuing mixing to 120°C to 130°C and then draining the rubber to obtain a first stage mixed rubber; S2, second stage mixing: after the first stage mixed rubber is left to stand for 8-16 hours, a peroxide crosslinking agent and a cyclic olefin polymer are added, the mixture is mixed to 100°C-110°C and then discharged to obtain the final mixed rubber; S3. Vulcanization: After the final rubber is formed, it is vulcanized to obtain a low-temperature resistant and low-compression permanent deformation rubber material.

[0024] Furthermore, the adding of carbon black in batches is to divide the carbon black into two parts of equal weight, and add them in two batches with an interval of 55-65 seconds.

[0025] Furthermore, the vulcanization treatment is vulcanization at 170° C.-180° C. for 8-10 minutes and secondary vulcanization at 145° C.-150° C. for 4-4.5 hours.

[0026] Beneficial effects of the present invention: (1) The hydrogenated nitrile rubber (95-105 parts) used in the present invention has a flexible molecular chain structure, which makes the material have excellent low-temperature resistance; the carbon black (70-90 parts) used effectively improves the rebound performance of the material, making the rubber material have the excellent characteristic of low compression permanent deformation; the antioxidant (1-3 parts) has the function of inhibiting oxidation reaction, protecting the molecular chain from being stable under high temperature and long-term use, and extending the service life; the internal release agent (1-3 parts) can reduce demoulding defects and improve production stability in combination with montmorillonite; the plasticizer (3-5 parts) enhances low-temperature elasticity, has good compatibility with PB, and reduces migration to maintain long-term stability; the peroxide crosslinker (4-8 parts) forms a three-dimensional network to provide basic mechanical strength and deformation resistance; the cyclic olefin polymer (1-3 parts) suppresses dimensional change with low anisotropy. The peroxide crosslinker and the cyclic olefin polymer work synergistically, the crosslinked network provides structural support for the cyclic olefin polymer, and the cyclic olefin polymer reduces stress concentration in the crosslinked network, thereby ensuring that the material has both structural strength and dimensional stability. The limit on the number of components corresponds to the optimal range in which each component functions. Excess or insufficient amount will affect the chain segment mobility and processability.

[0027] (2) The ZnO-PB-MMT composite particles (3-8 parts) used in the present invention improve the dispersibility of traditional ZnO through the core-shell structure, avoiding the low-temperature brittleness caused by excessive local cross-linking; while reducing the amount of ZnO, the strength is improved by the two-dimensional reinforcement of montmorillonite, and the flexibility of the PB chain segments offsets the rigidity of the inorganic phase to maintain low-temperature performance; montmorillonite and nano-ZnO synergistically enhance the resistance to thermal oxidative aging and extend the service life.

[0028] (3) The modified PB in the ZnO-PB-MMT composite particles used in the present invention is co-crosslinked with hydrogenated nitrile rubber and has good compatibility with plasticizers, reducing the impact of plasticizer migration on low-temperature performance; montmorillonite and carbon black form a complementary reinforcement network, synergistically improving high-temperature dimensional stability without affecting low-temperature compliance; the dispersant (1-3 parts) promotes the dispersion of the composite particles and carbon black, cooperates with the peroxide crosslinker to form a more uniform crosslinked structure, and is superimposed with the cyclic olefin polymer to improve the dimensional stability after temperature cycling; the montmorillonite organic modified layer cooperates with the internal release agent to reduce demolding defects and improve production stability. DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0030] Example 1

[0031] This embodiment provides a low-temperature resistant and low-compression permanent deformation rubber material, which is prepared by the following steps: S1. Take 50 parts of nano-ZnO and add it to 500 parts of toluene, and disperse it by ultrasonication (500W, 60min) to form a nano-ZnO suspension; dry 20 parts of CTAB-modified montmorillonite at 80℃ in vacuum for 12 hours, grind it through a 200-mesh sieve for later use; dissolve 30 parts of maleic anhydride-modified polybutadiene (maleic anhydride grafting rate of 4%, number average molecular weight of 6000) in the above nano-ZnO suspension, and stir it at 60℃ under nitrogen protection for 1 hour; add 20 parts of pretreated montmorillonite, raise the temperature to 80℃, and high-speed shear (3000rpm) for 2 hours; remove the toluene by rotary evaporation (60℃, -0.09MPa) to obtain ZnO-PB-MMT composite particles; S2, one-stage mixing: 100 parts of hydrogenated nitrile rubber (Zetpol ®4310, acrylonitrile content of 20%) was mixed in an internal mixer for 40 seconds, and then 1.5 parts of internal release agent (WS280), 2 parts of dispersant FL, 3 parts of plasticizer TP-95, 5 parts of ZnO-PB-MMT composite particles, and 2 parts of antioxidant 445 were added and mixed for 70 seconds. 80 parts of carbon black N990 (particle size 300nm) were first divided into two parts of equal weight and then added twice with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued to 130℃ and then the glue was discharged to obtain a mixed rubber. S3, second stage mixing: after the first stage rubber mix is ​​left to stand for 12 hours, 4 parts of peroxide crosslinking agent BIB-40GS and 1.5 parts of cyclic olefin polymer APL are added, and the mixture is mixed to 110°C and then discharged to obtain the final rubber mix; S4. Vulcanization: After the final rubber is formed, it is sent to a vulcanizer for vulcanization at 180°C for 8 minutes and secondary vulcanization at 150°C for 4 hours to reduce the compression set to obtain a low-temperature resistant and low-compression set rubber material.

[0032] Example 2

[0033] Compared with Example 1, this embodiment differs in that the dosage of the peroxide crosslinking agent BIB-40GS and APL is increased. The specific implementation steps of S3 are: S3, second stage mixing: after the first stage mixed rubber is left to stand for 10 hours, 6 parts of peroxide crosslinking agent BIB-40GS and 2 parts of cyclic olefin polymer APL are added, and the mixture is mixed to 110°C and then discharged to obtain the final mixed rubber; The remaining raw materials and preparation process remain the same as in Example 1.

[0034] Example 3

[0035] Compared with Example 1, this embodiment is different in that the dosage of the peroxide crosslinking agent BIB-40GS and APL is further increased. The specific implementation steps of S3 are: S3, second stage mixing: after the first stage rubber mix is ​​left to stand for 14 hours, 8 parts of peroxide crosslinking agent BIB-40GS and 3 parts of cyclic olefin polymer APL are added, and the mixture is mixed to 105°C and then discharged to obtain the final rubber mix; The remaining raw materials and preparation process remain the same as in Example 1.

[0036] Example 4

[0037] Compared with Example 1, this embodiment differs in that the amount of ZnO-PB-MMT composite particles is increased. The specific implementation steps of S2 are: S2, one-stage mixing: 100 parts of hydrogenated nitrile rubber (Zetpol ®4310, acrylonitrile content of 20%) was mixed in an internal mixer for 40 seconds, and then 1.5 parts of internal release agent (WS280), 2 parts of dispersant FL, 3 parts of plasticizer TP-95, 8 parts of ZnO-PB-MMT composite particles, and 2 parts of antioxidant 445 were added and mixed for 70 seconds. 80 parts of carbon black N990 (particle size 300nm) were first divided into two parts of equal weight and then added twice with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued to 130℃ and then the glue was discharged to obtain a mixed rubber. The remaining raw materials and preparation process remain the same as in Example 1.

[0038] Example 5

[0039] Compared with Example 1, this embodiment differs in that the amount of ZnO-PB-MMT composite particles is reduced. The specific implementation steps of S2 are: S2, one-stage mixing: 100 parts of hydrogenated nitrile rubber (Zetpol ® 4310, acrylonitrile content of 20%) was mixed in an internal mixer for 40 seconds, and then 1.5 parts of internal release agent (WS280), 2 parts of dispersant FL, 3 parts of plasticizer TP-95, 3 parts of ZnO-PB-MMT composite particles, and 2 parts of antioxidant 445 were added and mixed for 70 seconds. 80 parts of carbon black N990 (particle size 300nm) were first divided into two parts of equal weight and then added twice with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued to 130℃ and then the glue was discharged to obtain a mixed rubber. The remaining raw materials and preparation process remain the same as in Example 1.

[0040] Example 6

[0041] Compared with Example 1, this embodiment differs in that the antioxidant and plasticizer are replaced. The specific implementation steps of S2 are: S2, one-stage mixing: 100 parts of hydrogenated nitrile rubber (Zetpol ® 4310, acrylonitrile content of 20%) was mixed in an internal mixer for 40 seconds, and then 1.5 parts of internal release agent (WS280), 2 parts of dispersant FL, 3 parts of plasticizer TP-759, 5 parts of ZnO-PB-MMT composite particles, and 2 parts of antioxidant RD were added and mixed for 70 seconds. 80 parts of carbon black N990 (particle size 300nm) were first divided into two parts of equal weight and then added twice with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued to 130℃ and then the glue was discharged to obtain a mixed rubber. The remaining raw materials and preparation process remain the same as in Example 1.

[0042] Example 7

[0043] Compared with Example 1, this embodiment differs in that the content of each component in S2 is mainly adjusted. The specific implementation steps of S2 are: S2, one-stage mixing: 96 parts of hydrogenated nitrile rubber (Zetpol ® 4310, acrylonitrile content of 20%) was mixed in an internal mixer for 40 seconds, and then 2 parts of internal release agent (PS206), 1.5 parts of dispersant FL, 4 parts of plasticizer TP-95, 6 parts of ZnO-PB-MMT composite particles, and 1.5 parts of antioxidant 445 were added and mixed for 70 seconds. 75 parts of carbon black N990 (particle size 300nm) were first divided into two parts of equal weight and then added twice with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued to 130℃ and then the glue was discharged to obtain a mixed rubber. The remaining raw materials and preparation process remain the same as in Example 1.

[0044] Example 8

[0045] Compared with Example 1, this embodiment differs in that the content of each component in S2 is mainly adjusted. The specific implementation steps of S2 are: S2, one-stage mixing: 105 parts of hydrogenated nitrile rubber (Zetpol ® 4310, acrylonitrile content of 20%) was mixed in an internal mixer for 40 seconds, and then 2.5 parts of internal release agent (IOTA 257), 1 part of dispersant FL, 3.5 parts of plasticizer TP-95, 4 parts of ZnO-PB-MMT composite particles, and 2.5 parts of antioxidant 445 were added and mixed for 70 seconds. 85 parts of carbon black N990 (particle size 300nm) were first divided into two parts of equal weight and then added twice with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued to 130℃ and then the glue was discharged to obtain a mixed rubber. The remaining raw materials and preparation process remain the same as in Example 1.

[0046] Example 9

[0047] Compared with Example 1, this embodiment differs in that the content of each component in S1 is adjusted. The specific implementation steps of S1 are: S1. Take 55 parts of nano-ZnO and add it to 500 parts of toluene, and disperse it by ultrasonication (500W, 60min) to form a nano-ZnO suspension; dry 20 parts of CTAB-modified montmorillonite at 80℃ under vacuum for 12 hours, grind it through a 200-mesh sieve for later use; dissolve 35 parts of maleic anhydride-modified polybutadiene in the above nano-ZnO suspension, and stir it at 60℃ under nitrogen protection for 1 hour; add 18 parts of pretreated montmorillonite, heat it to 80℃, and high-speed shear (3000rpm) for 2 hours; remove the toluene by rotary evaporation (60℃, -0.09MPa) to obtain ZnO-PB-MMT composite particles; The remaining raw materials and preparation process remain the same as in Example 1.

[0048] Example 10

[0049] Compared with Example 1, this embodiment differs in that the modifier of the cationic modified montmorillonite is replaced. The specific implementation steps of S1 are: S1. Take 50 parts of nano-ZnO and add it to 500 parts of toluene, and disperse it by ultrasonication (500W, 60min) to form a nano-ZnO suspension; dry 20 parts of DTAC-modified montmorillonite at 80℃ in vacuum for 12 hours, grind it through a 200-mesh sieve for later use; dissolve 30 parts of maleic anhydride-modified polybutadiene in the above nano-ZnO suspension, and stir it at 60℃ under nitrogen protection for 1 hour; add 20 parts of pretreated montmorillonite, heat it to 80℃, and high-speed shear (3000rpm) for 2 hours; remove the toluene by rotary evaporation (60℃, -0.09MPa) to obtain ZnO-PB-MMT composite particles; The remaining raw materials and preparation process remain the same as in Example 1.

[0050] Comparative Example 1

[0051] Compared with Example 1, this comparative example differs in that carbon black N990 is replaced by carbon black N550. The specific implementation steps of S2 are as follows: S2, one-stage mixing: 100 parts of hydrogenated nitrile rubber (Zetpol ® 4310, acrylonitrile content of 20%) was mixed in an internal mixer for 40 seconds, and then 1.5 parts of internal release agent (WS280), 2 parts of dispersant FL, 3 parts of plasticizer TP-95, 5 parts of ZnO-PB-MMT composite particles, and 2 parts of antioxidant 445 were added and mixed for 70 seconds. 80 parts of carbon black N550 (particle size 300nm) were first divided into two parts of equal weight and then added twice with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued to 130℃ and then the glue was discharged to obtain a mixed rubber. The remaining raw materials and preparation process remain the same as in Example 1.

[0052] Comparative Example 2

[0053] This comparative example is compared with Example 1 in that the hydrogenated nitrile rubber Zetpol ® 4310 is replaced by THERBAN 3446. The specific implementation steps of S2 are: S2, first stage mixing: 100 parts of hydrogenated nitrile rubber (THERBAN 3446) were mixed in an internal mixer for 40 seconds, and then 1.5 parts of internal release agent (WS280), 2 parts of dispersant FL, 3 parts of plasticizer TP-95, 5 parts of ZnO-PB-MMT composite particles, and 2 parts of antioxidant 445 were added and mixed for 70 seconds. 80 parts of carbon black N990 (particle size 300nm) were first divided into two equal parts by weight and then added twice with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued until 130℃ and the rubber was discharged to obtain a first stage rubber mix. The remaining raw materials and preparation process remain the same as in Example 1.

[0054] Comparative Example 3

[0055] The difference between this comparative example and Example 1 is that the carbon black N990 is replaced by carbon black N550 and the hydrogenated nitrile rubber Zetpol is replaced by ® 4310 is replaced by THERBAN 3446. The specific implementation steps of S2 are: S2, first stage mixing: 100 parts of hydrogenated nitrile rubber (THERBAN 3446) were mixed in an internal mixer for 40 seconds, and then 1.5 parts of internal release agent (WS280), 2 parts of dispersant FL, 3 parts of plasticizer TP-95, 5 parts of ZnO-PB-MMT composite particles, and 2 parts of antioxidant 445 were added and mixed for 70 seconds. 80 parts of carbon black N550 (particle size 300nm) were first divided into two equal parts by weight and then added in two portions with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued until 130℃ and the rubber was discharged to obtain a first stage rubber mix. The remaining raw materials and preparation process remain the same as in Example 1.

[0056] Comparative Example 4

[0057] This comparative example is different from Example 1 in that the cationic modified montmorillonite is replaced by montmorillonite. The specific implementation steps of S1 are: S1. Take 50 parts of nano-ZnO and add it to 500 parts of toluene. Disperse it by ultrasonication (500W, 60min) to form a nano-ZnO suspension. Dissolve 30 parts of maleic anhydride-modified polybutadiene in the nano-ZnO suspension and stir it at 60°C under nitrogen for 1 hour. Add 20 parts of montmorillonite, raise the temperature to 80°C, and high-speed shear (3000rpm) for 2 hours. Remove the toluene by rotary evaporation (60°C, -0.09MPa) to obtain ZnO-PB-MMT composite particles. The remaining raw materials and preparation process remain the same as in Example 1.

[0058] Comparative Example 5

[0059] This comparative example is different from Example 1 in that no cationic modified montmorillonite is added. The specific implementation steps of S1 are: S1. Take 50 parts of nano-ZnO and add it to 500 parts of toluene. Disperse it by ultrasonication (500W, 60min) to form a nano-ZnO suspension. Dissolve 30 parts of maleic anhydride-modified polybutadiene in the nano-ZnO suspension and stir it at 60°C under nitrogen for 1 hour. Remove the toluene by rotary evaporation (60°C, -0.09MPa) to obtain ZnO-PB composite particles. The remaining raw materials and preparation process remain the same as in Example 1.

[0060] Comparative Example 6

[0061] This comparative example is different from Example 1 in that no maleic anhydride-modified polybutadiene is added. The specific implementation steps of S1 are: S1. Take 50 parts of nano-ZnO and add it to 500 parts of toluene, and disperse it by ultrasonication (500W, 60min) to form a nano-ZnO suspension; dry 20 parts of cationic modified montmorillonite at 80°C in vacuum for 12 hours, grind it through a 200-mesh sieve for later use; disperse 20 parts of pretreated montmorillonite in the above nano-ZnO suspension, stir it at 60°C under nitrogen protection for 1 hour; heat it to 80°C, and high-speed shear (3000rpm) for 2 hours; remove the toluene by rotary evaporation (60°C, -0.09MPa) to obtain ZnO-MMT composite particles; The remaining raw materials and preparation process remain the same as in Example 1.

[0062] Comparative Example 7

[0063] Compared with Example 1, this comparative example differs in that the ZnO-PB-MMT composite particles are replaced with ZnO. The specific implementation steps are as follows: S1, one-stage mixing: 100 parts of hydrogenated nitrile rubber (Zetpol ®4310, acrylonitrile content of 20%) was mixed in an internal mixer for 40 seconds, and then 1.5 parts of internal release agent (WS280), 2 parts of dispersant FL, 3 parts of plasticizer TP-95, 5 parts of ZnO, and 2 parts of antioxidant 445 were added and mixed for 70 seconds. 80 parts of carbon black N990 (particle size 300nm) was first divided into two parts of equal weight and then added twice with an interval of 60 seconds in between. When mixing to 90℃ and 110℃, the mixture was kept warm for 20 seconds each. Mixing was continued to 130℃ and then the glue was discharged to obtain a mixed rubber. S2, second stage mixing: after the first stage rubber mix is ​​allowed to stand for 12 hours, 4 parts of peroxide crosslinking agent BIB-40GS and 1.5 parts of cyclic olefin polymer APL are added, and the mixture is mixed to 110°C and then discharged to obtain the final rubber mix; S3. Vulcanization: After the final rubber is formed, it is sent to a vulcanizer for vulcanization at 180°C for 8 minutes and secondary vulcanization at 150°C for 4 hours to reduce the compression set to obtain a low-temperature resistant and low-compression set rubber material.

[0064] The remaining raw materials and preparation process remain the same as in Example 1.

[0065] Performance Testing

[0066] The performance tests of the low-temperature resistant and low-compression permanent deformation rubber materials prepared in Examples 1 to 10 and Comparative Examples 1 to 7 were performed. The results are shown in Table 1: Table 1

[0067] As shown in Table 1, in Examples 1-3, increasing the amount of peroxide crosslinker and APL reduced the 150°C compression set from 16.6% to 10.6%, and optimized the low-temperature TG from -39.5°C to -43.1°C. This directly confirms the synergistic mechanism of "the crosslinked network provides structural anchors for APL, and APL reduces stress concentration": the three-dimensional network formed by the peroxide enhances deformation resistance, while the low anisotropy of APL inhibits dimensional change. Together, these two achieve a balanced "strength-stability" balance, making the material more resistant to compression at high temperatures while maintaining flexibility at low temperatures.

[0068] The compression permanent deformation of Example 1 (5 parts) is 1.2%-0.9% lower than that of Example 4 (8 parts) and Example 5 (3 parts), which proves that the core-shell structure achieves uniform dispersion of ZnO through the steric effect (avoiding excessive local cross-linking), and the flexibility of the PB chain segment offsets the rigidity of montmorillonite, maintaining a low TG of -39.5°C, which perfectly matches the design goal of "improving dispersibility + maintaining low-temperature performance".

[0069] The compression set of Example 1 (CTAB modification) is 0.4% lower than that of Example 10 (DTAC modification) because the long-chain alkyl group of CTAB has better compatibility with PB and HNBR, and synergistically promotes particle dispersion with the dispersant FL, making the cross-linking structure more uniform.

[0070] Comparative Example 1 (N550) has a 6.7% higher compression set and a 101% lower elongation at break than Example 1, confirming the beneficial effect of the design of "matching large particle size N990 with low acrylonitrile HNBR": N990 avoids the obstruction of chain segment movement by small particle size carbon black, and is combined with Zetpol ® The 4310 flexible chain achieves a balance between low compression set and high elongation.

[0071] Comparative Examples 4-7 (absent montmorillonite / PB / unmodified / standard ZnO) all exhibited compression set >19% and a maximum low-temperature TG increase of 3.5°C. This is due to: 1) poor compatibility between the unmodified montmorillonite and the matrix (Comparative Example 4); 2) the inability to achieve inorganic-organic chemical grafting without PB (Comparative Example 6); and 3) poor dispersion of standard ZnO, leading to uneven crosslinking (Comparative Example 7). This demonstrates that the composite particles overcome the limitations of traditional ZnO dispersion and form a multi-dimensional reinforcement network with peroxide and APL, which is one of the keys to the material's combined low-temperature resistance and low compression set.

[0072] In summary, the low-temperature-resistant, low-compression set rubber material provided by the present invention solves the problem of maintaining excellent low-temperature performance while also achieving excellent compression set performance. It can be used in even lower temperatures and harsher environments, and has broad application prospects, particularly in new energy products.

[0073] The above disclosures are only a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A low temperature resistant and low compression permanent deformation rubber material, characterized in that: The invention comprises, by weight, 95-105 parts of hydrogenated nitrile rubber, 3-8 parts of ZnO-PB-MMT composite particles, 1-3 parts of antioxidant, 70-90 parts of carbon black, 1-3 parts of internal mold release agent, 1-3 parts of dispersant, 4-8 parts of peroxide crosslinking agent, 3-5 parts of plasticizer and 1-3 parts of cyclic olefin polymer.

2. The low-temperature resistant and low-compression permanent deformation rubber material according to claim 1, characterized in that: The ZnO-PB-MMT composite particles are prepared by the following steps: (1) Add nano ZnO to toluene and disperse it by ultrasonic to obtain a nano ZnO suspension; (2) Dissolve maleic anhydride modified polybutadiene in nano-ZnO suspension and stir under nitrogen protection; (3) Add pretreated cationic modified montmorillonite, heat to 75-80°C, high-speed shear, and rotary evaporate to obtain ZnO-PB-MMT composite particles.

3. The low-temperature resistant and low-compression permanent deformation rubber material according to claim 2, characterized in that: The weight ratio of the nano ZnO, toluene, maleic anhydride modified polybutadiene and cationic modified montmorillonite is (45-60): (450-600): (25-40): (15-25).

4. The low-temperature resistant and low-compression permanent deformation rubber material according to claim 2, characterized in that: The maleic anhydride-modified polybutadiene has a maleic anhydride grafting rate of 3%-5% and a number average molecular weight of 5000-8000; the modifier of the cationic-modified montmorillonite is one or a combination of CTAB, DTAC and STAB.

5. The low-temperature resistant and low-compression permanent deformation rubber material according to claim 2, characterized in that: The pretreatment comprises vacuum drying the montmorillonite, grinding and sieving the sieve; the aperture of the sieve is 180-220 mesh; the stirring comprises heating to 55-60° C. and stirring for 1-1.5 hours; and the high-speed shearing comprises shearing at a rotation speed of 3000 rpm for 2-3 hours.

6. The low-temperature resistant and low-compression permanent deformation rubber material according to claim 1, characterized in that: The model of the hydrogenated nitrile rubber is Zetpol ® 4310; Zetpol in the hydrogenated nitrile rubber ® The content of 4310 acrylonitrile is 18%-20%; the particle size of the carbon black is 201-500nm, and the specific model is carbon black N990; the dispersant model is dispersant FL.

7. The low-temperature resistant and low-compression permanent deformation rubber material according to claim 1, characterized in that: The antioxidant is any one or a combination of antioxidant 445, antioxidant RD and antioxidant MB; the internal release agent is any one or a combination of WS280, PS206 and IOTA 257.

8. The low-temperature resistant and low-compression permanent deformation rubber material according to claim 1, characterized in that: The plasticizer is any one or a combination of plasticizer TP-95, plasticizer TP-759 and plasticizer TP-90B; the cyclic olefin polymer is APL; and the peroxide crosslinking agent is peroxide crosslinking agent BIB-40GS.

9. A method for preparing a low-temperature resistant and low-compression permanent deformation rubber material, characterized in that: The method for preparing the rubber material according to any one of claims 1 to 8 comprises the following steps: S1, first stage mixing: mixing hydrogenated nitrile rubber for 35 seconds to 40 seconds, adding internal mold release agent, dispersant, plasticizer, ZnO-PB-MMT composite particles, and antioxidant and mixing for 60 seconds to 80 seconds; then adding carbon black in batches; keeping the temperature at 88-93°C and 108-113°C for 20-25 seconds respectively, continuing mixing to 120°C to 130°C and then draining the rubber to obtain a first stage mixed rubber; S2, second stage mixing: after the first stage mixed rubber is left to stand for 8-16 hours, a peroxide crosslinking agent and a cyclic olefin polymer are added, the mixture is mixed to 100°C-110°C and then discharged to obtain the final mixed rubber; S3. Vulcanization: After the final rubber is formed, it is vulcanized to obtain a low-temperature resistant and low-compression permanent deformation rubber material.

10. The method for preparing a low-temperature resistant and low-compression permanent deformation rubber material according to claim 9, characterized in that: The carbon black is added in batches by dividing the carbon black into two parts of equal weight and adding them twice with an interval of 55-65 seconds between them; the vulcanization treatment is vulcanization at 170-180°C for 8-10 minutes and secondary vulcanization at 145-150°C for 4-4.5 hours.

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