Hydrogenated butyronitrile-fluorosilicone blended rubber material and preparation method thereof

Abstract

The invention discloses a hydrogenated butyronitrile-fluorosilicone blended rubber material and a preparation method thereof, and relates to the technical field of high polymer materials. The hydrogenated butyronitrile-fluorosilicone blended rubber material is prepared by blending hydrogenated butyronitrile rubber compound and fluorosilicone rubber compound, the hydrogenated nitrile rubber compound comprises hydrogenated nitrile rubber, stearic acid, zinc oxide, an anti-aging agent, a reinforcing filler, a cross-linking agent and a vulcanizing agent; the fluorosilicone rubber compound comprises the following components: fluorosilicone rubber, a reinforcing agent, a heat-resistant agent, a dye and a vulcanizing agent. The hydrogenated butyronitrile rubber compound and the fluorosilicone rubber compound form physical crosslinking, and a stable three-dimensional network structure is formed under the synergistic effect of hydrogen bonds and Van der Waals force, so that the reinforcing effect is achieved, and the prepared blended rubber material has the characteristics of high hardness, excellent mechanical property, low-temperature stability and the like, and has good application prospects. The material can be applied to the fields of aviation sealing elements, rubber products for low-temperature environments, high-precision industrial bushings and the like.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and in particular to a hydrogenated nitrile-fluorosilicone blended rubber material and a preparation method thereof. Background Art

[0002] High-hardness rubber, due to its excellent wear resistance and mechanical strength, is widely used in aviation seals, industrial bushings, and wear-resistant parts. Existing technologies often rely on a reinforcement system consisting of phenolic resin, carbon black, and inorganic fillers. This synergistic combination of reinforcing fillers enhances rubber hardness, but the resulting rubber materials still have a hardness below 70 HA (Shore A hardness), resulting in poor wear resistance in practical applications. Furthermore, uneven filler dispersion leads to large fluctuations in mechanical properties. Furthermore, while the addition of phenolic resin improves hardness, it significantly degrades the material's low-temperature toughness, with the glass transition temperature (Tg) generally exceeding -30°C, making it difficult to maintain the elasticity required for aviation seals in ultra-low temperature environments (e.g., below -50°C). With the development of aviation, aerospace, and high-end equipment manufacturing, there is an urgent need for rubber materials that combine high hardness (≥70 HA), excellent low-temperature performance (Tg ≤ -50°C), and ease of processing. However, existing technologies cannot achieve a balance between low-temperature stability and mechanical properties while maintaining high hardness. Summary of the Invention

[0003] The main purpose of this application is to provide a hydrogenated nitrile-fluorosilicone blend rubber material and a preparation method thereof, aiming to solve the technical problem that existing rubber materials cannot have high hardness, excellent low-temperature performance and mechanical properties.

[0004] To achieve the above-mentioned purpose, the present application proposes a hydrogenated nitrile-fluorosilicone blend rubber material, which is prepared by blending hydrogenated nitrile rubber and fluorosilicone rubber; The components of the hydrogenated nitrile rubber compound include hydrogenated nitrile rubber, stearic acid, zinc oxide, an antioxidant, a reinforcing filler, a crosslinking agent and a vulcanizing agent; The components of the fluorosilicone rubber compound include fluorosilicone rubber, a reinforcing agent, a heat-resistant agent, a dye and a vulcanizing agent.

[0005] Optionally, the mass ratio of the hydrogenated nitrile rubber compound to the fluorosilicone rubber compound is (3-5): (15-17).

[0006] Optionally, the components of the hydrogenated nitrile rubber compound include, by weight: 90-110 parts of hydrogenated nitrile rubber, 0.2-1 part of stearic acid, 1-3 parts of zinc oxide, 0.5-2 parts of antioxidant, 20-40 parts of reinforcing filler, 1-3 parts of cross-linking agent and 2-4 parts of vulcanizing agent.

[0007] Optionally, the antioxidant is antioxidant 4010NA; the reinforcing filler is N330 carbon black; the crosslinking agent is triallyl isocyanurate; the heat-resistant agent is titanium dioxide; the dye is carbon black; and the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0008] Optionally, the components of the fluorosilicone compound include, by weight: 90-110 parts of fluorosilicone rubber, 20-40 parts of reinforcing agent, 1-3 parts of heat-resistant agent, 0.5-2 parts of dye, and 0.2-1 part of vulcanizing agent.

[0009] Optionally, the reinforcing agent is white carbon black; and the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0010] The present application also proposes a method for preparing a hydrogenated nitrile-fluorosilicone blended rubber material, comprising the following steps: After the hydrogenated nitrile rubber is masticated, stearic acid, zinc oxide, antioxidant, reinforcing filler, crosslinking agent and vulcanizing agent are added in sequence, and mixed in sections respectively, with the total mixing time being controlled to be 28 minutes to 52 minutes. After the mixing is completed, a hydrogenated nitrile rubber compound is obtained; After plasticizing the fluorosilicone rubber, a reinforcing agent, a heat-resistant agent, a dye and a vulcanizing agent are added in sequence and mixed in sections, with the total mixing time being controlled at 22 minutes to 38 minutes to obtain a fluorosilicone compound rubber; The hydrogenated nitrile rubber mix and the fluorosilicone rubber mix are respectively thin-passed, then uniformly blended, and thin-passed again to obtain a blended rubber material; The blended rubber material is subjected to hot pressing vulcanization and then to two-stage vulcanization to obtain a hydrogenated nitrile-fluorosilicone blended rubber material.

[0011] Optionally, after masticating the hydrogenated nitrile rubber, stearic acid, zinc oxide, an antioxidant, a reinforcing filler, a cross-linking agent, and a vulcanizing agent are sequentially added, and the mixture is mixed in sections, and the total mixing time is controlled to be 28 min-52 min. After the mixing is completed, the step of obtaining a hydrogenated nitrile rubber mixture comprises: The hydrogenated nitrile rubber is plasticized at room temperature at a speed of 45rpm-55rpm for 3min-7min, stearic acid is added, and mixing is continued for 3min-7min. Then, zinc oxide is added and mixing is continued for 8min-12min. Then, an antioxidant is added and mixing is continued for 3min-7min. Then, a reinforcing filler is added and mixing is continued for 8min-12min. Then, a cross-linking agent is added and mixing is continued for 3min-7min. Then, a vulcanizing agent is added and mixing is continued for 3min-7min. During the mixing process, the stirring speed is maintained at 45rpm-55rpm. After the mixing is completed, a hydrogenated nitrile rubber compound is obtained.

[0012] Optionally, the step of adding a reinforcing agent, a heat-resistant agent, a dye, and a vulcanizing agent to the fluorosilicone rubber after masticating the fluorosilicone rubber in sequence, and mixing them in sections, controlling the total mixing time to be 22 minutes to 38 minutes, to obtain the fluorosilicone rubber compound comprises: After plasticizing the fluorosilicone rubber at room temperature at a speed of 45rpm-55rpm for 3min-7min, a reinforcing agent is added, and after mixing for 8min-12min, a heat-resistant agent is added, and after mixing for 3min-7min, a dye is added, and after mixing for 3min-7min, a vulcanizing agent is added, and mixing is continued for 8min-12min. During the mixing process, the stirring speed is maintained at 45rpm-55rpm. After the mixing is completed, a fluorosilicone compound rubber is obtained.

[0013] Optionally, in the step of hot-pressing and vulcanizing the blended rubber material and then performing a second-stage vulcanization to obtain a hydrogenated nitrile-fluorosilicone blended rubber material, the temperature of hot-pressing and vulcanizing is 150°C-170°C, and the pressure of hot-pressing and vulcanizing is 5MPa-15MPa; the temperature of the second-stage vulcanization is 140°C-160°C, and the time of the second-stage vulcanization is 1h-3h.

[0014] This application has at least the following beneficial effects: This application uses hydrogenated nitrile rubber and fluorosilicone rubber as the matrix, and adds reinforcing fillers, heat-resistant agents, antioxidants, and vulcanizing agents and other additives for internal mixing. The polar acrylonitrile groups of the hydrogenated nitrile rubber form physical crosslinks with the fluorosilicone rubber through hydrogen bonds. Under the synergistic effect of hydrogen bonds and van der Waals forces, efficient bonding is achieved at the interface of the two phases, forming a stable three-dimensional network structure, thereby achieving a reinforcing effect; The present invention adopts mechanical blending in-situ reinforcement to blend hydrogenated nitrile rubber and fluorosilicone rubber to improve physical properties, thereby achieving uniform dispersion of hydrogenated nitrile rubber in fluorosilicone rubber, significantly improving the hardness and mechanical properties of the blended rubber material, and reducing costs. The low-polarity molecular chains of the fluorosilicone rubber in this application can still maintain the ability to move chain segments at low temperatures. The polar acrylonitrile groups of the dihydrogenated nitrile rubber form physical crosslinks with the fluorosilicone rubber through hydrogen bonds, inhibiting the freezing of the molecular chains, thereby lowering the glass transition temperature of the blended rubber material, allowing it to maintain excellent elastic recovery ability at extremely low temperatures, solving the problem of low-temperature embrittlement of traditional rubber. The blended rubber material prepared in this application has the characteristics of high hardness, excellent mechanical properties and low-temperature stability, and can be used in aviation seals, rubber products for low-temperature environments, high-precision industrial bushings and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0016] Figure 1 This is a graph showing the change in loss factor of the blended rubber material as a function of temperature according to an embodiment of the present application; Figure 2 This is a stress-strain curve diagram of the blended rubber material described in the embodiment of the present application; Figure 3 This is an SEM image of the blended rubber material described in Example 2 of the present application.

[0017] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0019] In order to solve the technical problems existing in the prior art, the embodiments of the present application provide a hydrogenated nitrile-fluorosilicone blended rubber material, which is prepared by blending hydrogenated nitrile rubber compound and fluorosilicone rubber compound; The components of the hydrogenated nitrile rubber compound include hydrogenated nitrile rubber, stearic acid, zinc oxide, an antioxidant, a reinforcing filler, a crosslinking agent and a vulcanizing agent; The components of the fluorosilicone rubber compound include fluorosilicone rubber, a reinforcing agent, a heat-resistant agent, a dye and a vulcanizing agent.

[0020] This application adopts the method of in-situ reinforcement of polymers, selects hydrogenated nitrile rubber and fluorosilicone rubber as the matrix, and adds reinforcing fillers, heat-resistant agents, antioxidants, vulcanizing agents and other additives. The polar acrylonitrile groups of hydrogenated nitrile rubber form physical cross-links with fluorosilicone rubber through hydrogen bonds. Under the synergistic effect of hydrogen bonds and van der Waals forces, efficient bonding of the two-phase interface is achieved, forming a stable three-dimensional network structure, thereby achieving a reinforcement effect.

[0021] As an implementation method of the present application, the mass ratio of the hydrogenated nitrile rubber compound to the fluorosilicone rubber compound is (3-5): (15-17).

[0022] Preferably, the mass ratio of hydrogenated nitrile rubber and fluorosilicone rubber is 4:16. By optimizing the blending ratio of hydrogenated nitrile rubber and fluorosilicone rubber, the Shore hardness of the blended rubber material can be as high as 82.2HA and the tensile strength can be as high as 13.7MPa, which are significantly higher than the traditional phenolic resin reinforcement system (hardness ≤70HA, tensile strength ≤6.2MPa), meeting the stringent requirements of aviation seals, industrial wear-resistant parts, etc. for high hardness and tensile properties.

[0023] As an embodiment of the present application, the components of the hydrogenated nitrile rubber compound include, by weight: 90-110 parts of hydrogenated nitrile rubber, 0.2-1 part of stearic acid, 1-3 parts of zinc oxide, 0.5-2 parts of antioxidant, 20-40 parts of reinforcing filler, 1-3 parts of cross-linking agent and 2-4 parts of vulcanizing agent.

[0024] As an implementation method of the present application, the antioxidant is antioxidant 4010NA; the reinforcing filler is N330 carbon black; the cross-linking agent is triallyl isocyanurate; and the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0025] Specifically, antioxidant 4010NA, as a high-efficiency antioxidant and antiozonant, can inhibit the oxidative degradation and ozone aging of rubber molecular chains, thereby significantly extending the service life of the material in high-temperature, high-oxygen environments; reinforcing filler N330 carbon black can enhance the mechanical properties of the rubber matrix through physical adsorption and mechanical interlocking effects, and the high specific surface area of ​​N330 carbon black (80m 2 / g-110m 2 / g) can promote the interfacial bonding between filler and rubber, improve wear resistance, and reduce surface wear during dynamic use. The crosslinking agent triallyl isocyanurate (TAIC) serves as a multifunctional crosslinking aid, participating in free radical crosslinking reactions and improving vulcanization efficiency. It works synergistically with the vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane to form a uniform crosslinked network, reduce vulcanization defects, and increase crosslink density. 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane (DBPH) is also beneficial for generating a uniform three-dimensional network structure, endowing the material with excellent elastic recovery. The flexible crosslinking bonds of DBPH work synergistically with the siloxane segments of the fluorosilicone compound to lower the glass transition temperature. Meanwhile, the antioxidant 4010NA inhibits the material's low-temperature oxidative embrittlement, thereby endowing the blended rubber material with excellent low-temperature stability.

[0026] As an implementation method of the present application, the components of the fluorosilicone compound include, by weight: 90-110 parts of fluorosilicone rubber, 20-40 parts of reinforcing agent, 1-3 parts of heat-resistant agent, 0.5-2 parts of dye and 0.2-1 part of vulcanizing agent.

[0027] As an implementation method of the present application, the reinforcing agent is white carbon black; the heat-resistant agent is titanium dioxide; the dye is carbon black; and the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0028] Specifically, the reinforcing agent white carbon black and N330 carbon black can form a double reinforcing network, while 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate optimize the cross-linking structure, thereby achieving a reinforcing effect and realizing a balance between high hardness and high strength of the blended rubber material; the heat-resistant agent titanium dioxide is uniformly dispersed in the rubber material, which can prolong the thermal decomposition of the polymer chain of the rubber molecules at high temperature, thereby extending the service life of the blended rubber material in a high temperature environment and improving the high-temperature stability; the dye carbon black not only meets the dyeing requirements, but also can improve the wear resistance and tear resistance of the rubber.

[0029] The present invention also provides a method for preparing a hydrogenated nitrile-fluorosilicone blended rubber material, comprising the following steps: S10, after the hydrogenated nitrile rubber is masticated, stearic acid, zinc oxide, antioxidant, reinforcing filler, crosslinking agent and vulcanizing agent are added in sequence, and the mixture is mixed in sections, and the total mixing time is controlled to be 28min-52min. After the mixing is completed, a hydrogenated nitrile rubber compound is obtained.

[0030] In the specific implementation process, the hydrogenated nitrile rubber is plasticized at a speed of 45rpm-55rpm at room temperature for 3min-7min, stearic acid is added, and mixing is continued for 3min-7min. Then, zinc oxide is added, and mixing is continued for 8min-12min. Then, an antioxidant is added, and mixing is continued for 3min-7min. Then, a reinforcing filler is added, and mixing is continued for 8min-12min. Then, a cross-linking agent is added, and mixing is continued for 3min-7min. Then, a vulcanizing agent is added, and mixing is continued for 3min-7min. During the mixing process, the stirring speed is maintained at 45rpm-55rpm. After the mixing is completed, a hydrogenated nitrile rubber mixture is obtained.

[0031] S20. After plasticating the fluorosilicone rubber, a reinforcing agent, a heat-resistant agent, a dye, and a vulcanizing agent are added in sequence, and mixed in sections respectively, with the total mixing time being controlled to be 22 min-38 min, to obtain a fluorosilicone rubber compound.

[0032] In the specific implementation process, the fluorosilicone rubber is plasticized at a speed of 45rpm-55rpm at room temperature for 3min-7min, a reinforcing agent is added, mixed for 8min-12min, and then a heat-resistant agent is added. After mixing for 3min-7min, a dye is added. After mixing for 3min-7min, a vulcanizing agent is added and mixing is continued for 8min-12min. The stirring speed is maintained at 45rpm-55rpm during the mixing process. After the mixing is completed, a fluorosilicone compound rubber is obtained.

[0033] S30, thin-passing the hydrogenated nitrile rubber mix and the fluorosilicone rubber mix, blending them evenly, and thin-passing them again to obtain a blended rubber material.

[0034] Specifically, the present application thin-passes the hydrogenated nitrile rubber and the fluorosilicone rubber in a two-roll mill for 8 to 12 times, and then thin-passes the mixed system rubber for 8 to 12 times in a two-roll mill after blending. The hydrogenated nitrile rubber and the fluorosilicone rubber are blended by mechanical blending in situ enhancement to improve the physical properties, thereby achieving uniform dispersion of the hydrogenated nitrile rubber in the fluorosilicone rubber, significantly improving the hardness and mechanical properties of the blended rubber material, and the preparation process is simple and feasible, cost-effective, and suitable for industrial production.

[0035] S40, performing hot-press vulcanization on the blended rubber material, and then performing two-stage vulcanization to obtain a hydrogenated nitrile-fluorosilicone blended rubber material.

[0036] In the specific implementation process, the temperature of hot pressing vulcanization is 150° C.-170° C., and the pressure of hot pressing vulcanization is 5 MPa-15 MPa; the temperature of the second stage vulcanization is 140° C.-160° C., and the time of the second stage vulcanization is 1 h-3 h.

[0037] The present application adopts a combination of hot press vulcanization and two-stage vulcanization to produce a polymer in-situ reinforced blended rubber material. The blended rubber material has excellent vulcanization properties. When tested with a rotorless vulcanizer, its maximum torque value can reach 8.82dN·m.

[0038] The above technical solutions of the present application are described in detail below with reference to specific embodiments.

[0039] Example 1 A hydrogenated nitrile-fluorosilicone blended rubber material is prepared by the following steps: 100 g of hydrogenated nitrile rubber was added to an internal mixer, and the mixture was plasticated at room temperature at a speed of 50 rpm for 5 min. Then, 0.53 g of stearic acid was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min. Then, 2 g of zinc oxide was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min. Then, 1 g of antioxidant 4010NA was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min. Then, 30 g of N330 carbon black was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min. Then, 2 g of triallyl isocyanurate was added as a cross-linking agent, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min. Then, 3 g of pure bis(2,5- ... 100 g of fluorosilicone rubber was added to an internal mixer and plasticized at room temperature at a speed of 50 rpm for 5 min, 31 g of white carbon black was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min, 2 g of heat-resistant agent was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min, 1 g of dye was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min, 0.53 g of dichloromethane solution was slowly added dropwise, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min to obtain a fluorosilicone rubber compound; The hydrogenated nitrile rubber mix and the fluorosilicone rubber mix are respectively thin-passed on a two-roll mill for 10 times to produce sheets, and the hydrogenated nitrile rubber mix and the fluorosilicone rubber mix are uniformly blended in a mass ratio of 3:17, and then thin-passed on a two-roll mill for 10 times to obtain a blended rubber material; The blended rubber material is hot-pressed and vulcanized on a flat vulcanizer at a temperature of 160° C. and a pressure of 10 MPa. The vulcanization time is determined according to TC90 in the vulcanization characteristic value measured by a rotorless vulcanizer. The blended rubber material is then subjected to two-stage vulcanization at a temperature of 150° C. and a time of 2 h to obtain a hydrogenated nitrile-fluorosilicone blended rubber material.

[0040] Example 2 A hydrogenated nitrile-fluorosilicone blended rubber material is prepared by the following steps: 100 g of hydrogenated nitrile rubber was added to an internal mixer, and the mixture was plasticated at room temperature at a speed of 50 rpm for 5 min. Then, 0.2 g of stearic acid was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min. Then, 1 g of zinc oxide was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min. Then, 0.5 g of antioxidant 4010NA was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min. Then, 20 g of N330 carbon black was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min. Then, 1 g of triallyl isocyanurate was added as a cross-linking agent, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min. Then, 2 g of bis(2,5- ... 100 g of fluorosilicone rubber was added into an internal mixer and plasticized at room temperature at a speed of 50 rpm for 5 min, 20 g of white carbon black was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min, 1 g of heat-resistant agent was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min, 0.5 g of dye was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min, 0.25 g of dichloromethane solution was slowly added dropwise, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min to obtain a fluorosilicone rubber compound; The hydrogenated nitrile rubber mix and the fluorosilicone rubber mix are respectively thin-passed on a two-roll mill for 10 times to produce sheets, and the hydrogenated nitrile rubber mix and the fluorosilicone rubber mix are uniformly blended in a mass ratio of 4:16, and then thin-passed on a two-roll mill for 10 times to obtain a blended rubber material; The blended rubber material is hot-pressed and vulcanized on a flat vulcanizer at a temperature of 150° C. and a pressure of 5 MPa. The vulcanization time is determined according to TC90 in the vulcanization characteristic value measured by a rotorless vulcanizer. The blended rubber material is then subjected to two-stage vulcanization at a temperature of 140° C. and a time of 3 h to obtain a hydrogenated nitrile-fluorosilicone blended rubber material.

[0041] Example 3 A hydrogenated nitrile-fluorosilicone blended rubber material is prepared by the following steps: 100 g of hydrogenated nitrile rubber was added to an internal mixer, and the mixture was plasticated at room temperature at a speed of 50 rpm for 5 min. Then, 1 g of stearic acid was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min. Then, 3 g of zinc oxide was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min. Then, 2 g of antioxidant 4010NA was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min. Then, 40 g of N330 carbon black was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min. Then, 3 g of triallyl isocyanurate was added as a cross-linking agent, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min. Then, 4 g of bis(2,5- ... 100 g of fluorosilicone rubber was added to an internal mixer and plasticized at room temperature at a speed of 50 rpm for 5 min, 40 g of white carbon black was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min, 3 g of heat-resistant agent was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min, 2 g of dye was added, and the mixture was mixed at room temperature at a speed of 50 rpm for 5 min, 1 g of dichloromethane solution was slowly added dropwise, and the mixture was mixed at room temperature at a speed of 50 rpm for 10 min to obtain a fluorosilicone rubber compound; The hydrogenated nitrile rubber mix and the fluorosilicone rubber mix are respectively thin-passed on a two-roll mill for 10 times to produce sheets, and the hydrogenated nitrile rubber mix and the fluorosilicone rubber mix are uniformly blended in a mass ratio of 5:15, and then thin-passed on a two-roll mill for 10 times to obtain a blended rubber material; The blended rubber material is hot-pressed and vulcanized on a flat vulcanizer at a temperature of 170° C. and a pressure of 15 MPa. The vulcanization time is determined according to TC90 in the vulcanization characteristic value measured by a rotorless vulcanizer. The blended rubber material is then subjected to two-stage vulcanization at a temperature of 160° C. and a time of 1 h to obtain a hydrogenated nitrile-fluorosilicone blended rubber material.

[0042] Experimental example 1. Hardness testing was performed on the hydrogenated nitrile-fluorosilicone blend rubber material prepared in the Examples of this application. A Shore A durometer (Model: LX-A) was used according to GB / T 531.1-2008, "Rubber, Vulcanized or Thermoplastic—Test Method for Indentation Hardness." The test conditions were: sample thickness ≥ 6 mm, spacing ≥ 6 mm between test points, and an average of five test points. The test results are shown in Table 1 below.

[0043] Table 1

[0044] As can be seen from Table 1, the hydrogenated nitrile-fluorosilicone blend rubber materials prepared in the embodiments of the present application have a relatively high hardness, which is greater than 70HA and can reach up to 82.2HA. Compared with the rubber materials prepared by the traditional reinforcement system (hardness ≤ 70HA), their hardness is significantly improved.

[0045] 2. Test the glass transition temperature (Tg) of the hydrogenated nitrile-fluorosilicone blend rubber material prepared in the embodiment of this application by dynamic thermomechanical analysis (DMA). The test equipment uses a dynamic thermomechanical analyzer (model: TAInstruments Q800). The test conditions are: single-frequency tensile mode, frequency 1Hz, heating rate 3℃ / min, temperature range -80℃ to 50℃, sample specifications are: length × width × thickness = 20 mm × 5 mm × 1 mm; obtain the loss factor (tanδ) temperature change curve, and take the temperature corresponding to the tanδ peak as the glass transition temperature (Tg). The test results are as follows: Figure 1 shown.

[0046] Depend on Figure 1 It can be seen that the loss factor curves of Examples 1-3 show that the Tg of all blended rubber materials is lower than -50°C (the lowest is -53.4°C in Example 2). This is mainly because the polar acrylonitrile groups of the hydrogenated nitrile rubber form physical crosslinks with the fluorosilicone rubber through hydrogen bonds, inhibiting the freezing of the molecular chains, and the flexible siloxane segments of the fluorosilicone rubber significantly improve the low-temperature toughness of the material, thereby reducing the Tg. The rubber material prepared by the traditional reinforcement system is brittle at low temperatures (Tg = -28.5°C) due to the rigid structure of the phenolic resin, indicating that the blended rubber material prepared in the present application has better low-temperature stability.

[0047] 3. The tensile properties of the hydrogenated nitrile-fluorosilicone blend rubber material prepared in the examples of this application were tested in accordance with GB / T 528-2009 "Vulcanized rubber or thermoplastic rubber - Determination of tensile stress-strain properties". The test equipment used was a universal material testing machine (model: Instron 5967) to record the stress-strain curve. Figure 2 shown.

[0048] Depend on Figure 2 It can be seen that according to the stress-strain curves of the blended rubber materials of Examples 1-3, the tensile strength of the blended rubber materials is 8 MPa-13 MPa. Among them, Example 2 has the highest tensile strength of 13.7 MPa, which is better than ordinary silicone rubber and fluorosilicone rubber, indicating that it has good tensile properties.

[0049] 4. Using a field emission scanning electron microscope (model: FEI Nova NanoSEM 450), a scanning electron microscope (SEM) analysis was performed on the hydrogenated nitrile-fluorosilicone blended rubber material prepared in Example 2 of the present application to observe the compatibility of the two-phase interface of the blended rubber material and the dispersion state of the filler, and the following was obtained: Figure 3 SEM images shown.

[0050] Depend on Figure 3 It can be seen that the interface between hydrogenated nitrile rubber and fluorosilicone rubber is fuzzy, and there is no phase separation area > 1 μm, indicating that the two rubber compounds have good compatibility and no obvious phase separation, avoiding the phase separation defects of traditional blending systems.

[0051] In summary, the present application achieves uniform dispersion of hydrogenated nitrile rubber in fluorosilicone rubber through mechanical stirring and blending, and achieves efficient bonding at the interface of the two phases through the synergistic effect of hydrogen bonds (cyanide groups of hydrogenated nitrile rubber and siloxane chains of fluorosilicone rubber) and van der Waals forces. SEM images show no significant phase separation (phase domain size <1μm), the filler is evenly dispersed, and a stable three-dimensional network structure is formed, thereby achieving a reinforcement effect. By optimizing the blending ratio of hydrogenated nitrile rubber to fluorosilicone rubber (4:16), the Shore hardness of the blended rubber material can reach up to 82.2HA and the tensile strength can reach up to 13.7MPa, which are significantly higher than traditional phenolic resin reinforcement systems (hardness ≤70HA, tensile strength ≤6.2MPa), meeting the stringent requirements of aviation seals, industrial wear-resistant parts, etc. for high hardness and tensile strength. Dynamic thermomechanical analysis shows that the glass transition temperature of the blended rubber material is as low as -53.4°C, and it can still maintain excellent elastic recovery ability at extremely low temperatures, solving the problem of low-temperature embrittlement of traditional rubber. The above results show that the blended rubber material prepared in this application has the characteristics of high hardness, excellent mechanical properties and low-temperature stability, and can be used in aviation seals, rubber products for low-temperature environments, high-precision industrial bushings and other fields.

[0052] The above description is merely an optional embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification and drawings under the inventive concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A hydrogenated nitrile-fluorosilicone blend rubber material, characterized in that: It is prepared by blending hydrogenated nitrile rubber and fluorosilicone rubber; The components of the hydrogenated nitrile rubber compound include hydrogenated nitrile rubber, stearic acid, zinc oxide, an antioxidant, a reinforcing filler, a crosslinking agent and a vulcanizing agent; The components of the fluorosilicone rubber compound include fluorosilicone rubber, a reinforcing agent, a heat-resistant agent, a dye and a vulcanizing agent.

2. The hydrogenated nitrile-fluorosilicone blend rubber material according to claim 1, characterized in that: The mass ratio of the hydrogenated nitrile rubber compound to the fluorosilicone rubber compound is (3-5): (15-17).

3. The hydrogenated nitrile-fluorosilicone blend rubber material according to claim 1, characterized in that: The components of the hydrogenated nitrile rubber compound include, by weight, 90-110 parts of hydrogenated nitrile rubber, 0.2-1 part of stearic acid, 1-3 parts of zinc oxide, 0.5-2 parts of antioxidant, 20-40 parts of reinforcing filler, 1-3 parts of crosslinking agent and 2-4 parts of vulcanizing agent.

4. The hydrogenated nitrile-fluorosilicone blend rubber material according to claim 1 or 3, characterized in that: The antioxidant is antioxidant 4010NA; the reinforcing filler is N330 carbon black; the cross-linking agent is triallyl isocyanurate; and the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

5. The hydrogenated nitrile-fluorosilicone blend rubber material according to claim 1, characterized in that: The components of the fluorosilicone rubber compound include, by weight, 90-110 parts of fluorosilicone rubber, 20-40 parts of a reinforcing agent, 1-3 parts of a heat-resistant agent, 0.5-2 parts of a dye, and 0.2-1 part of a vulcanizing agent.

6. The hydrogenated nitrile-fluorosilicone blend rubber material according to claim 1 or 5, characterized in that: The reinforcing agent is white carbon black; the heat-resistant agent is titanium dioxide; the dye is carbon black; and the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

7. A method for preparing the hydrogenated nitrile-fluorosilicone blend rubber material according to any one of claims 1 to 6, characterized in that: The following steps are involved: After the hydrogenated nitrile rubber is masticated, stearic acid, zinc oxide, antioxidant, reinforcing filler, crosslinking agent and vulcanizing agent are added in sequence, and mixed in sections respectively, with the total mixing time being controlled to be 28 minutes to 52 minutes. After the mixing is completed, a hydrogenated nitrile rubber compound is obtained; After plasticizing the fluorosilicone rubber, a reinforcing agent, a heat-resistant agent, a dye and a vulcanizing agent are added in sequence and mixed in sections, with the total mixing time being controlled at 22 minutes to 38 minutes to obtain a fluorosilicone compound rubber; The hydrogenated nitrile rubber mix and the fluorosilicone rubber mix are respectively thin-passed, then uniformly blended, and thin-passed again to obtain a blended rubber material; The blended rubber material is subjected to hot pressing vulcanization and then to two-stage vulcanization to obtain a hydrogenated nitrile-fluorosilicone blended rubber material.

8. The method for preparing the hydrogenated nitrile-fluorosilicone blend rubber material according to claim 7, wherein: The method comprises the following steps: after the hydrogenated nitrile rubber is masticated, stearic acid, zinc oxide, an antioxidant, a reinforcing filler, a cross-linking agent, and a vulcanizing agent are sequentially added, and the mixing is performed in sections, and the total mixing time is controlled to be 28 minutes to 52 minutes. After the mixing is completed, a hydrogenated nitrile rubber compound is obtained, comprising: The hydrogenated nitrile rubber is plasticized at room temperature at a speed of 45rpm-55rpm for 3min-7min, stearic acid is added, and mixing is continued for 3min-7min. Then, zinc oxide is added and mixing is continued for 8min-12min. Then, an antioxidant is added and mixing is continued for 3min-7min. Then, a reinforcing filler is added and mixing is continued for 8min-12min. Then, a cross-linking agent is added and mixing is continued for 3min-7min. Then, a vulcanizing agent is added and mixing is continued for 3min-7min. During the mixing process, the stirring speed is maintained at 45rpm-55rpm. After the mixing is completed, a hydrogenated nitrile rubber compound is obtained.

9. The method for preparing the hydrogenated nitrile-fluorosilicone blend rubber material according to claim 7, wherein: The step of adding a reinforcing agent, a heat-resistant agent, a dye and a vulcanizing agent to the fluorosilicone rubber after plasticating, and mixing them in sections respectively, controlling the total mixing time to be 22 minutes to 38 minutes, to obtain the fluorosilicone rubber compound comprises: After plasticizing the fluorosilicone rubber at room temperature at a speed of 45rpm-55rpm for 3min-7min, a reinforcing agent is added, and after mixing for 8min-12min, a heat-resistant agent is added, and after mixing for 3min-7min, a dye is added, and after mixing for 3min-7min, a vulcanizing agent is added, and mixing is continued for 8min-12min. During the mixing process, the stirring speed is maintained at 45rpm-55rpm. After the mixing is completed, a fluorosilicone compound rubber is obtained.

10. The method for preparing the hydrogenated nitrile-fluorosilicone blend rubber material according to claim 7, characterized in that: In the step of hot-pressing and vulcanizing the blended rubber material and then performing a second-stage vulcanization to obtain a hydrogenated nitrile-fluorosilicone blended rubber material, the temperature of the hot-pressing and vulcanizing is 150° C.-170° C., and the pressure of the hot-pressing and vulcanizing is 5 MPa-15 MPa; the temperature of the second-stage vulcanization is 140° C.-160° C., and the time of the second-stage vulcanization is 1 h-3 h.

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