Rubber material composition, rubber product and preparation method of rubber product

Abstract

The invention belongs to the technical field of materials, and particularly relates to a rubber material composition, a rubber product and a preparation method of the rubber product. The rubber material composition comprises natural rubber, epoxidized natural rubber, resin and an initiator, the resin contains carbonyl, and the initiator comprises tert-butyl peroxybenzoate. In the application, an epoxy group in the epoxidized natural rubber and active groups such as carbonyl in the resin are subjected to a cross-linking reaction under the initiation action of free radicals generated by thermal decomposition of the tert-butyl peroxybenzoate to form a three-dimensional network structure, so that the independent motility of a rubber molecular chain is reduced; the rubber can keep good physical and mechanical properties at high temperature, so that the heat resistance of a rubber product is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of materials, and particularly relates to a rubber material composition, a rubber product and a preparation method thereof. Background Art

[0002] A magnetorheological shock absorber is a device that uses electromagnetic reactions and is based on input information from sensors that monitor the movement of the vehicle body and wheels to respond in real time to road conditions and driving environments. The magnetorheological shock absorber provides fast, smooth, continuously variable damping force with an economical and reliable component structure, reducing vehicle body vibration and increasing the adhesion of the tires to various road surfaces. Different from traditional shock absorption systems, there are no tiny valve structures in the magnetorheological shock absorber, nor does it achieve the shock absorption effect through the flow resistance of the liquid. The magnetorheological shock absorber helps to provide excellent vehicle body control and buffer the recoil force received by each wheel, maximizing the stability of the vehicle and improving driving performance and comfort. The magnetic vehicle control system applies magnetorheological (MR) fluid and shock absorbers without electromechanical control valves to provide rapid-response and powerful shock absorption damping force control, which is widely used in the automotive field.

[0003] Rubber has the following advantages: high elasticity, high viscoelasticity, impact stiffness greater than dynamic stiffness, and dynamic stiffness greater than static stiffness, which is beneficial to reducing impact deformation and dynamic deformation. The stress-strain curve of rubber is an elliptical hysteresis line, and its area is equal to the vibration energy (damping) converted into heat in each vibration cycle, which can be adjusted through formula design; rubber is an incompressible material (Poisson's ratio is 0.5); the shape of rubber can be freely selected, and the hardness can be adjusted through formula design to meet the requirements of stiffness and strength in different directions. Therefore, magnetorheological shock absorbers are generally made of rubber materials, and rubber materials are generally prepared with natural rubber materials as the main raw materials and various auxiliary materials added. However, natural rubber materials have poor heat resistance, poor fatigue resistance and aging resistance, and are only suitable for working environments with temperatures below 70°C. However, the operating conditions of magnetorheological shock absorbers are complex, and under long-term vibration conditions, heat is easily generated, and the rubber materials are prone to aging failure, which greatly affects the service life. Summary of the Invention

[0004] In view of this, the present invention provides a rubber material composition, a rubber product and a preparation method thereof to improve the heat resistance of the rubber material.

[0005] To achieve the above solution, the technical solution of the present invention is as follows:

[0006] In a first aspect, the present application provides a rubber material composition, which includes natural rubber, epoxidized natural rubber, resin and initiator, the resin contains carbonyl, and the initiator includes tert-butyl peroxybenzoate.

[0007] In this application, the epoxy groups in the epoxidized natural rubber and the active groups such as carbonyl groups in the resin undergo a cross-linking reaction under the initiation of free radicals generated by the thermal decomposition of tert-butyl perbenzoate, forming a three-dimensional network structure, reducing the independent mobility of rubber molecular chains, enabling the rubber to maintain good physical and mechanical properties at high temperatures, thereby improving the heat resistance of rubber products; moreover, by adding epoxidized natural rubber with good oil resistance and heat resistance, the oil resistance and heat resistance of rubber products can be improved, and the service life of rubber products can be extended.

[0008] In this application, the epoxidized natural rubber is at least one of ENR-10, ENR-20, ENR-30, ENR-40, and ENR-50. In this application, ENR-N (N is 10, 20, 30, 40, or 50) refers to epoxidized natural rubber with an epoxidation rate of N%.

[0009] Optionally, the mass ratio of the natural rubber, the epoxidized natural rubber, the resin, and the initiator is 80-150:10-50:10-30:3-9, preferably 80-150:20-50:15-30:4-9.

[0010] Optionally, the epoxidation rate of the epoxidized natural rubber is 8 mol%-52 mol%.

[0011] Optionally, the resin is selected from ethylene-vinyl acetate copolymer resin (abbreviated as EVA resin).

[0012] In this application, the ethylene-vinyl acetate copolymer resin can not only undergo a cross-linking reaction with the epoxy groups in the epoxidized natural rubber under the initiation of free radicals generated by the thermal decomposition of tert-butyl perbenzoate, forming a three-dimensional network structure, reducing the independent mobility of rubber molecular chains, enabling the rubber to maintain good physical and mechanical properties at high temperatures, and improving the heat resistance of the rubber; the ethylene-vinyl acetate copolymer resin has the characteristic of a relatively high melt index and is more easily plasticized during the processing, which is beneficial to reducing the processing temperature, improving the fluidity, and further enhancing the processing smoothness.

[0013] Optionally, the initiator further includes tert-butyl peroxy pivalate.

[0014] Optionally, in the initiator, the mass percentage content of tert-butyl peroxy pivalate is 10 wt%-30 wt%, preferably 15 wt%-30 wt%.

[0015] In this application, when tert-butyl peroxy pivalate and tert-butyl perbenzoate are used in combination, the half-life of the thermal decomposition of tert-butyl perbenzoate can be adjusted, more free radicals can be generated, the cross-linking reaction efficiency can be improved, the cross-linking degree can be increased, and further the heat resistance can be improved.

[0016] Optionally, the rubber material composition further comprises an antioxidant, an antiwear agent, a reinforcing filler, a processing aid, and a heat-conducting filler.

[0017] In the present application, by adding an antioxidant to the rubber material composition, the oxidation reaction of rubber raw materials such as natural rubber and epoxidized natural rubber can be inhibited, the aging process can be delayed, and the aging resistance of rubber products can be improved; by adding an antiwear agent to the rubber material composition, the intermolecular interaction force of rubber raw materials such as natural rubber and epoxidized natural rubber can be increased, and the abrasion resistance of rubber products can be improved; by adding a reinforcing filler to the rubber material composition, the strength of rubber products can be improved; by adding a processing aid to the rubber material composition, the processing performance can be improved, and the smoothness of production can be enhanced; by adding a heat-conducting filler to the rubber material composition, the heat conduction performance of rubber raw materials such as natural rubber and epoxidized natural rubber can be increased, heat can be timely exported from the rubber products, the temperature of the rubber products can be reduced, and thus the heat resistance of rubber products can be improved.

[0018] Optionally, the mass ratio of the antioxidant, the antiwear agent, the reinforcing filler, the processing aid, and the heat-conducting filler is 3 - 6:15 - 35:57 - 173:2 - 5:10 - 40, preferably 4 - 6:20 - 35:60 - 173:3 - 5:15 - 40.

[0019] Optionally, the mass ratio of the antioxidant to natural rubber is 3 - 6:80 - 150, preferably 4 - 6:80 - 150.

[0020] Optionally, the antioxidant is selected from at least one of 2,2,4 - trimethyl - 1,2 - dihydroquinoline polymer (i.e., antioxidant 4010NA), 6 - ethoxy - 2,2,4 - trimethyl - 1,2 - dihydroquinoline (i.e., antioxidant AW), and N,N'-dimethylphenyl - p - phenylenediamine (i.e., antioxidant 3100).

[0021] In the present application, antioxidants such as 2,2,4 - trimethyl - 1,2 - dihydroquinoline polymer (i.e., antioxidant 4010NA), 6 - ethoxy - 2,2,4 - trimethyl - 1,2 - dihydroquinoline (i.e., antioxidant AW), and N,N'-dimethylphenyl - p - phenylenediamine (i.e., antioxidant 3100) can not only inhibit the oxidation reaction of rubber raw materials such as natural rubber and epoxidized natural rubber, delay the aging process, and improve the aging resistance of rubber products, but also prevent the cracking of rubber products caused by ozone under dynamic conditions. In addition, they can reduce the flex fatigue caused by mechanical stress and improve the durability of rubber products.

[0022] Optionally, the antiwear agent is selected from polytetrafluoroethylene (i.e., PTFE).

[0023] In this application, polytetrafluoroethylene can reduce the friction between rubber raw materials such as natural rubber and epoxidized natural rubber and other raw materials, reduce wear, and extend the service life of rubber products; it can also utilize its excellent high-temperature resistance to further improve the heat resistance of rubber products.

[0024] Optionally, the reinforcing filler includes carbon black, silica, ceramic powder, and graphite powder.

[0025] In this application, carbon black can not only improve the physical and mechanical properties of rubber products, but also improve the processing performance of raw materials and enhance the smoothness of production; silica can not only improve the physical and mechanical properties of rubber products, but also form a "protective layer" with a hardness higher than that of rubber raw materials on the surface of rubber raw materials such as natural rubber and epoxidized natural rubber, improving the wear resistance of rubber products; ceramic powder can not only improve the physical and mechanical properties of rubber products, but also absorb the thermal decomposition products in rubber raw materials such as natural rubber and epoxidized natural rubber, reduce the thermal decomposition of rubber raw materials such as natural rubber and epoxidized natural rubber, and improve the thermal stability of rubber products; graphite powder can not only improve the physical and mechanical properties of rubber products, but also reduce wear in an environment with intense friction and extend the service life of rubber products.

[0026] Optionally, the mass ratio of the carbon black, the silica, the ceramic powder, and the graphite powder is 30 - 80:20 - 60:2 - 8:5 - 25, preferably 35 - 80:25 - 60:3 - 8:6 - 25.

[0027] Optionally, the processing aid is selected from at least one of a dispersant, a homogenizer, a tackifier, and an internal mold release agent.

[0028] In this application, the dispersant can reduce the viscosity of rubber raw materials such as natural rubber and epoxidized natural rubber, improve fluidity and processing formability, increase production efficiency, and reduce energy consumption and production costs; the homogenizer can promote the rapid and uniform mixing of natural rubber and epoxidized natural rubber, stabilize the phase structure, and improve processing performance; the tackifier can promote the uniform mixing of raw materials, reduce the friction coefficient and operation difficulty, improve processing formability, and increase production efficiency; the internal mold release agent can improve the fluidity of the rubber compound in the mold cavity, make the rubber compound fill the mold, increase the injection speed and demolding effect, and reduce quality problems caused by internal friction of the rubber compound and adhesion to mechanical molds.

[0029] Optionally, the dispersant is selected from polyethylene glycol ether, fatty alcohol polyoxyethylene ether, or a combination of the two.

[0030] In this application, polyethylene glycol ether can not only reduce the viscosity of rubber raw materials such as natural rubber and epoxidized natural rubber, improve fluidity, processing and molding properties, increase production efficiency, reduce energy consumption and production costs, but also increase the lubricity and plasticity of rubber products, reduce power consumption during processing, and extend the service life of rubber products.

[0031] In this application, fatty alcohol polyoxyethylene ether can not only reduce the viscosity of rubber raw materials such as natural rubber and epoxidized natural rubber, improve fluidity, processing and molding properties, increase production efficiency, reduce energy consumption and production costs, but also lower the glass transition temperature of rubber raw materials such as natural rubber and epoxidized natural rubber, and improve the flexibility and ductility of rubber products.

[0032] Optionally, the homogenizer is selected from at least one of paraffin oil, mineral oil, aromatic oil, cycloalkane oil, phthalate and phosphate ester.

[0033] In this application, substances such as paraffin oil, mineral oil, aromatic oil, cycloalkane oil, phthalate, phosphate ester, etc. can not only promote the rapid and uniform mixing of natural rubber and epoxidized natural rubber, stabilize the phase structure, improve processing performance, but also improve the flexibility and ductility of rubber raw materials such as natural rubber and epoxidized natural rubber, reduce the hardness and brittleness of rubber raw materials such as natural rubber and epoxidized natural rubber, improve the softness and elasticity of rubber products, and regulate the interfacial interaction between rubber raw materials such as natural rubber and epoxidized natural rubber and reinforcing fillers, optimize the dispersion and reinforcement effect of reinforcing fillers, and improve the hardness, elasticity, tear strength and other indexes of rubber products.

[0034] Optionally, the tackifier is selected from rosin.

[0035] In this application, rosin can not only promote the uniform mixing of each raw material, reduce the friction coefficient and operation difficulty, improve the processability of forming, increase production efficiency, but also change the surface chemical properties of rubber raw materials such as natural rubber and epoxidized natural rubber, improve the adhesion between rubber raw materials such as natural rubber and epoxidized natural rubber and other raw materials, and improve the stability and durability of rubber products in various use environments.

[0036] Optionally, the internal mold release agent is selected from polytetrafluoroethylene.

[0037] Optionally, the heat-conducting filler is selected from at least one of alumina, zinc oxide and magnesium oxide.

[0038] In this application, substances such as alumina, zinc oxide, and magnesia can not only increase the thermal conductivity of rubber raw materials such as natural rubber and epoxidized natural rubber, conduct heat out of rubber products in a timely manner, reduce the temperature of rubber products, and improve the heat resistance of rubber products, but also utilize the excellent wear resistance of substances such as alumina and zinc oxide and the excellent thermal stability of magnesia to improve the wear resistance and thermal stability of rubber products.

[0039] Optionally, the rubber material composition further includes a carbon black dispersant.

[0040] In this application, the carbon black dispersant can improve the dispersion effect of carbon black and improve the mechanical properties of rubber products.

[0041] Optionally, the mass ratio of the carbon black dispersant to the carbon black is 1-3:30-80, preferably 1.5-3:30-80.

[0042] Optionally, the carbon black dispersant is selected from polyvinyl alcohol.

[0043] Optionally, the degree of polymerization of the polyvinyl alcohol is 1500-2000, preferably 1600-2000; the degree of alcoholysis of the polyvinyl alcohol is 80 mol%-99 mol%, preferably 85 mol%-99 mol%.

[0044] In this application, polyvinyl alcohol can improve the dispersion effect of carbon black, improve the mechanical properties of rubber products, and also utilize its excellent adhesiveness and plasticity to improve the ductility and plasticity of rubber products and enhance the mechanical strength and toughness of rubber products.

[0045] In a second aspect, this application also provides a rubber product, which is prepared from the rubber material composition as described above.

[0046] Optionally, the rubber product includes a magnetorheological shock absorber.

[0047] In a third aspect, this application also provides a preparation method of the rubber product as described above, including the following steps:

[0048] Mix and plasticate the natural rubber and the epoxidized natural rubber to obtain a rubber mixture;

[0049] Mix the rubber mixture with the resin and the initiator, then carry out internal mixing, filtration, aftertreatment, molding, and cooling to obtain the rubber product.

[0050] Optionally, the temperature of the plasticating is 55-65 °C, preferably 58-65 °C; the duration of the plasticating is 45-75 s, preferably 50-75 s.

[0051] Optionally, the temperature of the kneading is 75 - 85°C, preferably 78 - 85°C; the duration of the kneading is 150 - 200 s, preferably 160 - 200 s.

[0052] Optionally, the temperature of the curing is 110 - 120°C, preferably 115 - 120°C; the duration of the curing is 50 - 70 s, preferably 60 - 70 s. Detailed implementation mode

[0053] The present invention will be further described below through specific specific examples. It should be noted that the specific material ratios, process conditions, results, etc. described in the embodiments of the present invention are only used to illustrate the present invention and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered by the protection scope of the present invention.

[0054] An embodiment of the present application provides a rubber material composition, which includes natural rubber, epoxidized natural rubber, resin, initiator, antioxidant, wear-resistant agent, reinforcing filler, processing aid, heat-conducting filler, and carbon black dispersant. The mass ratio of natural rubber, epoxidized natural rubber, resin, initiator, antioxidant, wear-resistant agent, reinforcing filler, processing aid to heat-conducting filler is 80 - 150:10 - 50:10 - 30:3 - 9:3 - 6:15 - 35:57 - 173:2 - 5:10 - 40;

[0055] The resin is selected from ethylene-vinyl acetate copolymer resin;

[0056] The initiator includes tert-butyl peroxybenzoate;

[0057] The antioxidant is selected from at least one of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, and N,N'-dimethylphenyl-p-phenylenediamine;

[0058] The wear-resistant agent is selected from polytetrafluoroethylene. The reinforcing filler includes carbon black, silica, ceramic powder, and graphite powder. The mass ratio of carbon black, silica, ceramic powder to graphite powder is 30 - 80:20 - 60:2 - 8:5 - 25;

[0059] The processing aid is selected from at least one of dispersant, homogenizer, tackifier, and internal mold release agent;

[0060] The dispersant is selected from polyethylene glycol ether, fatty alcohol polyoxyethylene ether, or a combination of the two;

[0061] The homogenizer is selected from at least one of paraffin oil, mineral oil, aromatic oil, cycloalkane oil, phthalate, and phosphate ester;

[0062] The tackifier is selected from rosin;

[0063] The internal mold release agent is selected from polytetrafluoroethylene;

[0064] The thermal conductive filler is selected from at least one of alumina, zinc oxide and magnesium oxide;

[0065] The mass ratio of the carbon black dispersant to the carbon black is 1-3:30-80, and the carbon black dispersant is selected from polyvinyl alcohol.

[0066] In another embodiment of the present application, the initiator further includes tert-butyl peroxy pivalate, and in the initiator, the mass percentage content of tert-butyl peroxy pivalate is 10wt%-30wt%

[0067] Another embodiment of the present application also provides a rubber product, which is prepared from the rubber material composition as described above, and the rubber product includes a magnetorheological shock absorber.

[0068] Another embodiment of the present application also provides a preparation method of the rubber product as described above, including the following steps:

[0069] Mix natural rubber and epoxidized natural rubber, and then plastify at 55-65°C for 45-75 s to obtain a rubber mixture;

[0070] Mix the rubber mixture with resin and initiator, then knead at 75-85°C for 150-200 s, filter, cure at 110-120°C for 50-70 s, mold, and cool to obtain the rubber product.

[0071] The present invention will be described in detail below through specific exemplary embodiments. It should be understood that the following embodiments are only used to specifically illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the protection scope of the present invention. The specific process parameters and the like in the following examples are also only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, rather than being limited to the specific values in the following examples.

[0072] Example 1

[0073] A rubber product is prepared from the following raw materials according to the following steps:

[0074] S1. Mix 100 parts of natural rubber and 30 parts of epoxidized natural rubber ENR-30 (epoxidation rate is 30 mol%), and then plastify at 60°C for 60 s to obtain a rubber mixture;

[0075] S2. Mix 50 parts of carbon black N330, 2 parts of carbon black dispersant polyvinyl alcohol 1788, 40 parts of silica, 5 parts of ceramic powder, 5 parts of initiator tert-butyl perbenzoate, 20 parts of graphite powder, 5 parts of antioxidant 2,2,4-trimethyl-1,2-dihydroquinoline polymer (i.e., antioxidant 4010NA), 20 parts of wear-resistant agent polytetrafluoroethylene (i.e., PTFE), 3 parts of fatty alcohol polyoxyethylene ether JFC-5, 20 parts of thermal conductive filler (composed of alumina, zinc oxide and magnesia in a mass ratio of 1:1:2), and 20 parts of ethylene-vinyl acetate copolymer resin (i.e., EVA resin). Then, conduct closed mixing at 80 °C for 180 s, filter, conduct after-ripening at 115 °C for 60 s, form, cool, and place in a vulcanizer for vulcanization treatment to obtain a rubber product.

[0076] Example 2

[0077] A rubber product is prepared from the following raw materials by the following steps:

[0078] S1. Mix 80 parts of natural rubber and 50 parts of epoxidized natural rubber ENR-50 (epoxidation rate is 50 mol%) and conduct plasticizing at 55 °C for 75 s to obtain a rubber mixture;

[0079] S2. Mix 30 parts of carbon black (composed of carbon black N330 and carbon black N500 in a mass ratio of 3:1), 2 parts of carbon black dispersant polyvinyl alcohol 1788 (i.e., polyvinyl alcohol with a degree of polymerization of 1700 and a degree of alcoholysis of 88 mol%), 60 parts of silica, 2 parts of ceramic powder, 9 parts of initiator tert-butyl perbenzoate, 5 parts of graphite powder, 3 parts of antioxidant 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline (i.e., antioxidant AW), 15 parts of wear-resistant agent polytetrafluoroethylene (i.e., PTFE), 5 parts of paraffin oil, 10 parts of thermal conductive filler alumina, and 10 parts of ethylene-vinyl acetate copolymer resin (i.e., EVA resin). Then, conduct closed mixing at 85 °C for 150 s, filter, conduct after-ripening at 120 °C for 50 s, form, cool, and place in a vulcanizer for vulcanization treatment to obtain a rubber product.

[0080] Example 3

[0081] A rubber product is prepared from the following raw materials by the following steps:

[0082] S1. Mix 150 parts of natural rubber, 2 parts of epoxidized natural rubber ENR-10 (epoxidation rate is 10 mol%), 3 parts of epoxidized natural rubber ENR-20 (epoxidation rate is 20 mol%), and 3 parts of ENR-40 (epoxidation rate is 40 mol%) and conduct plasticizing at 65 °C for 45 s to obtain a rubber mixture;

[0083] S2. Mix 80 parts of carbon black (composed of carbon black N330 and carbon black N600 in a mass ratio of 1:2), 2 parts of carbon black dispersant polyvinyl alcohol 1788, 20 parts of silica, 8 parts of ceramic powder, 3 parts of initiator tert-butyl peroxybenzoate, 25 parts of graphite powder, 6 parts of antioxidant N,N'-dimethyl-p-phenylenediamine (i.e., antioxidant 3100), 35 parts of wear-resistant agent polytetrafluoroethylene (i.e., PTFE), 2 parts of processing aids (composed of tackifier rosin and internal mold release agent polytetrafluoroethylene in a mass ratio of 1:1), 40 parts of heat-conducting filler magnesium oxide, and 30 parts of ethylene-vinyl acetate copolymer resin (i.e., EVA resin), then carry out kneading at 75 °C for 200 s, filter, carry out after-treatment at 110 °C for 70 s, form, cool, and place in a vulcanizer for vulcanization treatment to obtain a rubber product.

[0084] Example 4

[0085] Prepare a rubber product in the same manner as in Example 1 except for the following conditions:

[0086] S2. Mix 50 parts of carbon black N330, 2 parts of carbon black dispersant polyvinyl alcohol 1788, 40 parts of silica, 5 parts of ceramic powder, 5 parts of initiator (composed of tert-butyl peroxy pivalate and tert-butyl peroxybenzoate in a mass ratio of 1:9), 20 parts of graphite powder, 5 parts of antioxidant 2,2,4-trimethyl-1,2-dihydroquinoline polymer (i.e., antioxidant 4010NA), 20 parts of wear-resistant agent polytetrafluoroethylene (i.e., PTFE), 3 parts of fatty alcohol polyoxyethylene ether JFC-5, 20 parts of heat-conducting filler (composed of alumina, zinc oxide, and magnesium oxide in a mass ratio of 1:1:2), and 20 parts of ethylene-vinyl acetate copolymer resin (i.e., EVA resin), then carry out kneading at 80 °C for 180 s, filter, carry out after-treatment at 115 °C for 60 s, form, cool, and place in a vulcanizer for vulcanization treatment to obtain a rubber product.

[0087] That is, the difference between this example and Example 1 is that the initiator also includes tert-butyl peroxy pivalate, and in the initiator, the mass percentage content of tert-butyl peroxy pivalate is 10 wt%.

[0088] Example 5

[0089] Prepare a rubber product in the same manner as in Example 1 except for the following conditions:

[0090] S2. Mix 50 parts of carbon black N330, 2 parts of carbon black dispersant polyvinyl alcohol 1788, 40 parts of silica, 5 parts of ceramic powder, 5 parts of initiator (composed of tert-butyl peroxy pivalate and tert-butyl peroxybenzoate in a mass ratio of 3:7), 20 parts of graphite powder, 5 parts of antioxidant 2,2,4-trimethyl-1,2-dihydroquinoline polymer (i.e., antioxidant 4010NA), 20 parts of wear-resistant agent polytetrafluoroethylene (i.e., PTFE), 3 parts of fatty alcohol polyoxyethylene ether JFC-5, 20 parts of heat-conducting filler (composed of alumina, zinc oxide and magnesium oxide in a mass ratio of 1:1:2) and 20 parts of ethylene-vinyl acetate copolymer resin (i.e., EVA resin), then conduct internal mixing at 80 °C for 180 s, filter, conduct after-treatment at 115 °C for 60 s, form, cool, and place in a vulcanizer for vulcanization treatment to obtain a rubber product.

[0091] That is, the difference between this example and Example 1 is that: the initiator also includes tert-butyl peroxy pivalate, and in the initiator, the mass percentage content of tert-butyl peroxy pivalate is 30 wt%.

[0092] Comparative Example 1

[0093] Prepare a rubber product in the same manner as in Example 1 except for the following conditions:

[0094] S1. Mix 100 parts of natural rubber and 30 parts of epoxidized natural rubber ENR-30 (epoxidation rate is 30 mol%) and conduct plasticizing at 60 °C for 60 s to obtain a rubber mixture;

[0095] S2. Mix 50 parts of carbon black N330, 2 parts of carbon black dispersant polyvinyl alcohol 1788, 40 parts of silica, 5 parts of ceramic powder, 5 parts of initiator tert-butyl peroxybenzoate, 20 parts of graphite powder, 5 parts of antioxidant 2,2,4-trimethyl-1,2-dihydroquinoline polymer (i.e., antioxidant 4010NA), 20 parts of wear-resistant agent polytetrafluoroethylene (i.e., PTFE), 3 parts of fatty alcohol polyoxyethylene ether JFC-5 and 20 parts of heat-conducting filler (composed of alumina, zinc oxide and magnesium oxide in a mass ratio of 1:1:2), then conduct internal mixing at 80 °C for 180 s, filter, conduct after-treatment at 115 °C for 60 s, form, cool to obtain a rubber product.

[0096] That is, the difference between this comparative example and Example 1 is that: ethylene-vinyl acetate copolymer resin (i.e., EVA resin) is not added.

[0097] Performance Test

[0098] The compression set of the rubber products prepared in Test Examples 1-5 and Comparative Example 1 was tested according to "GB / T 7759.1-2015 Determination of compression set of vulcanized rubber or thermoplastic rubber - Part 1: At normal and high temperatures" after being treated at 150 °C for 24 h. The results are shown in Table 1.

[0099] Table 1 Test Results

[0100] Group Compression set (150°C, 24 h) Example 1 15％ Example 2 16％ Example 3 18％ Example 4 11％ Example 5 10％ Comparative Example 1 31％

[0101] As can be seen from Table 1, compared with Comparative Example 1 (without adding ethylene-vinyl acetate copolymer resin), the compression set (150 °C, 24 h) of Example 1 (added with ethylene-vinyl acetate copolymer resin) was significantly reduced. This result indicates that in this application, the epoxy groups in the epoxidized natural rubber and the active groups such as carbonyl groups in the resin undergo a cross-linking reaction under the initiation of free radicals generated by the thermal decomposition of tert-butyl perbenzoate, forming a three-dimensional network structure, reducing the independent mobility of the rubber molecular chains, enabling the rubber to maintain better physical and mechanical properties at high temperatures, and thus improving the heat resistance of the rubber.

[0102] As can be seen from Table 1, compared with Example 1 (the initiator is tert-butyl perbenzoate), the compression set (150 °C, 24 h) of Example 4 (the initiator is a composition formed by tert-butyl perbenzoate and tert-butyl peroxyvalerate, and the mass percentage content of tert-butyl peroxyvalerate in the initiator is 10 wt%) and Example 5 (the initiator is a composition formed by tert-butyl perbenzoate and tert-butyl peroxyvalerate, and the mass percentage content of tert-butyl peroxyvalerate in the initiator is 30 wt%) was significantly reduced. This result indicates that in this application, the compound use of tert-butyl peroxyvalerate and tert-butyl perbenzoate can adjust the half-life of the thermal decomposition of tert-butyl perbenzoate, promote the generation of more free radicals, improve the cross-linking reaction efficiency, increase the cross-linking degree, and further improve the heat resistance.

[0103] The above examples are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above examples without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A rubber material composition, characterized in that, The rubber material composition comprises natural rubber, epoxidized natural rubber, resin and an initiator, the resin contains a carbonyl group, and the initiator includes tert-butyl peroxybenzoate.

2. The rubber material composition according to claim 1, characterized in that, The mass ratio of the natural rubber, the epoxidized natural rubber, the resin to the initiator is 80-150:10-50:10-30:3-9; and / or, the resin is selected from ethylene-vinyl acetate copolymer resin; and / or, the initiator further includes tert-butyl peroxy pivalate; and / or, the rubber material composition further includes an antioxidant, an abrasion resistance agent, a reinforcing filler, a processing aid and a heat-conducting filler.

3. The rubber material composition according to claim 2, characterized in that, In the initiator, the mass percentage content of tert-butyl peroxy pivalate is 10wt%-30wt%; and / or, the mass ratio of the antioxidant, the abrasion resistance agent, the reinforcing filler, the processing aid to the heat-conducting filler is 3-6:15-35:57-173:2-5:10-40; and / or, the mass ratio of the antioxidant to the natural rubber is 3-6:80-150.

4. The rubber material composition according to claim 2, characterized in that, The antioxidant is selected from at least one of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline and N,N'-dimethyl-p-phenylenediamine; and / or, the abrasion resistance agent is selected from polytetrafluoroethylene; and / or, the reinforcing filler includes carbon black, silica, ceramic powder and graphite powder; and / or, the processing aid is selected from at least one of a dispersant, a homogenizer, a tackifier and an internal mold release agent; and / or, the heat-conducting filler is selected from at least one of alumina, zinc oxide and magnesium oxide.

5. The rubber material composition according to claim 4, wherein The mass ratio of the carbon black, the silica, the ceramic powder to the graphite powder is 30-80:20-60:2-8:5-25; and / or, the dispersant is selected from polyethylene glycol ether, fatty alcohol polyoxyethylene ether or a combination thereof; and / or, the homogenizer is selected from at least one of paraffin oil, mineral oil, aromatic oil, cycloalkane oil, phthalate and phosphate; and / or, the tackifier is selected from rosin; and / or, the internal mold release agent is selected from polytetrafluoroethylene; and / or, the rubber material composition further includes a carbon black dispersant.

6. The rubber material composition according to claim 5, characterized in that, The mass ratio of the carbon black dispersant to the carbon black is 1-3:30-80; and / or, the carbon black dispersant is selected from polyvinyl alcohol.

7. A rubber product, characterized in that, The rubber product is prepared from the rubber material composition according to any one of claims 1-6.

8. The rubber product according to claim 7, characterized in that, The rubber product includes a magnetorheological shock absorber.

9. The method for preparing a rubber product according to claim 7 or 8, characterized in that, Comprising the following steps: Mix and plasticate the natural rubber and the epoxidized natural rubber to obtain a rubber mixture; Mix the rubber mixture with the resin and the initiator, then carry out internal mixing, filtration, aftermixing, shaping and cooling to obtain the rubber product.

10. The method for preparing a rubber product according to claim 9, characterized in that, The temperature of the plasticating is 55-65°C, and the duration of the plasticating is 45-75s; and / or, the temperature of the internal mixing is 75-85°C, and the duration of the internal mixing is 150-200s; and / or, the temperature of the aftermixing is 110-120°C, and the duration of the aftermixing is 50-70s.