Novel oil-resistant rubber and preparation method thereof

Abstract

The invention discloses novel oil-resistant rubber and a preparation method thereof. The novel oil-resistant rubber comprises the following raw materials: a plurality of rubbers such as ternary polymerization fluororubber and nitrile rubber, fillers such as nano carbon black and surface modified calcium fluoride, and auxiliaries such as a bisphenol AF vulcanizing agent; the preparation method comprises the following steps: pretreating the raw materials, mixing, and molding, wherein the vulcanization temperature is 160-180 DEG C, and the pressure is 10-20 MPa. The rubber can effectively bear corrosion of methanol gasoline and diesel oil, and is excellent in oil resistance due to synergism of various rubbers and enhancement of the filler; nano carbon black and the like improve the mechanical property; the antioxidant and the anti-aging agent are matched with a vulcanization system, so that the aging resistance is good. The sealing agent can be widely applied to the fields of automobile fuel systems, chemical pipeline sealing and the like and has good application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber materials, and particularly relates to a novel oil-resistant rubber and a preparation method thereof. Background Art

[0002] Against the backdrop of the accelerating adjustment of the global energy structure and the booming development of the automotive industry, the application of new fuels and the performance optimization of traditional fuels have become the focus of industry attention. As a highly potential new clean alternative fuel, methanol gasoline has been continuously expanding its application scale globally due to its wide sources, high combustion efficiency, and low pollutant emissions. The promotion of methanol gasoline not only helps to alleviate the shortage of petroleum resources but also reduces the dependence on imported oil, enhances the security and stability of energy supply, and at the same time conforms to the global trend of energy conservation, emission reduction, and response to climate change. However, the methanol component contained in methanol gasoline has strong polarity and corrosiveness, which poses extremely stringent requirements on the rubber materials in contact with it.

[0003] Traditional rubber materials, such as ordinary nitrile rubber, when in contact with methanol gasoline, due to the mismatch between their molecular structure and the chemical properties of methanol gasoline, methanol molecules are extremely easy to penetrate into the interior of the rubber, resulting in the swelling of the rubber. Swelling will damage the molecular chain structure of the rubber, significantly reducing the physical and mechanical properties of the rubber, manifested as a decrease in hardness, a weakening of tensile strength, and a deterioration of elasticity. At the same time, the corrosive components in methanol gasoline will also trigger the aging reaction of the rubber, accelerating the breakage and cross-linking of the rubber molecular chains, causing the rubber to become hard and brittle, and ultimately losing its sealing performance, resulting in serious safety hazards such as fuel leakage. In the automotive fuel system, once the rubber seals fail due to the corrosion of methanol gasoline, it will not only affect the normal operation of the vehicle but may also cause major safety accidents such as fires, seriously threatening personal safety and property safety.

[0004] On the other hand, diesel, as one of the main energy sources in the fields of transportation and industrial power, has maintained a high usage volume for a long time. Diesel contains various complex organic components, such as aromatics and alkanes, and these components also pose relatively high requirements on the oil resistance of rubber materials. Traditional oil-resistant rubbers will gradually be swollen and eroded by the organic solvents in diesel during long-term contact, resulting in an increase in the volume and weight of the rubber and a deterioration of its physical properties. Moreover, with the continuous improvement of diesel quality standards and the widespread application of low-sulfur and low-aromatic diesel, new challenges have been brought to the adaptability of rubber materials. Some rubber materials that performed well in the environment of ordinary diesel may show unstable performance in the environment of low-sulfur diesel.

[0005] Most of the oil-resistant rubbers currently available on the market are developed and improved for a single fuel medium, and have obvious deficiencies in the comprehensive performance of resistance to methanol gasoline and diesel. Although some oil-resistant rubbers have good tolerance to diesel, they cannot work stably for a long time in a methanol gasoline environment; and some rubber materials developed for methanol gasoline have oil resistance in a diesel environment that is difficult to meet actual needs. In addition, the existing oil-resistant rubbers also have certain limitations in terms of aging resistance and mechanical properties, and cannot simultaneously meet the requirements of high performance, long life, and high reliability of rubber materials in the fields of automotive fuel systems and chemical pipeline sealing. Therefore, the development of a new type of oil-resistant rubber that can effectively resist the corrosion of methanol gasoline and diesel and has excellent aging resistance and mechanical properties has important practical significance and broad market prospects for promoting the coordinated development of the energy industry and the rubber material industry and ensuring the safe and stable operation of related fields. Summary of the invention

[0006] The purpose of the present invention is to provide a new type of oil-resistant rubber, which can effectively withstand methanol gasoline corrosion and diesel corrosion through reasonable raw material formula design and preparation process optimization, and has excellent oil resistance, aging resistance and mechanical properties. At the same time, a preparation method is provided to realize industrial production.

[0007] To achieve the above purpose, the present invention adopts the following technical means:

[0008] A novel oil-resistant rubber comprises the following raw materials by weight: 10-30 parts of ternary polymerized fluororubber, 20-40 parts of nitrile rubber, 10-20 parts of carboxylated nitrile rubber, 5-15 parts of chloroprene rubber, 10-20 parts of nano carbon black, 5-10 parts of surface-modified calcium fluoride, 3-8 parts of layered silicate, 5-12 parts of nano calcium carbonate, 1-3 parts of bisphenol AF vulcanizing agent, 0.5-2 parts of triallyl triisocyanurate, 0.3-1 parts of benzyl triphenylphosphonium chloride, 5-15 parts of fluororubber, 2-6 parts of polyisobutylene, 3-8 parts of dioctyl phthalate, 0.5-2 parts of stearic acid, 2-5 parts of magnesium oxide, 3-7 parts of magnesium hydroxide, 1-3 parts of zinc oxide, 0.8-2.5 parts of accelerator, 0.2-1 parts of sulfur, 0.5-1.5 parts of antioxidant and 0.5-1.5 parts of anti-aging agent.

[0009] In a further embodiment of the present invention, the raw materials are as follows by weight: 20 parts of terpolymer fluororubber, 30 parts of nitrile rubber, 15 parts of carboxylated nitrile rubber, 10 parts of chloroprene rubber, 15 parts of nano carbon black, 8 parts of surface-modified calcium fluoride, 6 parts of layered silicate, 8 parts of nano calcium carbonate, 2 parts of bisphenol AF curing agent, 1.5 parts of triallyl isocyanurate, 0.8 part of benzyltriphenylphosphonium chloride, 10 parts of fluororubber, 4 parts of polyisobutylene, 6 parts of dioctyl phthalate, 1 part of stearic acid, 4 parts of magnesium oxide, 5 parts of magnesium hydroxide, 2 parts of zinc oxide, 0.8 part of accelerator, 0.5 part of sulfur, 1 part of antioxidant, and 1 part of antiozonant.

[0010] In a further embodiment of the present invention, the accelerator is 0.5 - 1.5 parts of accelerator DM and 0.3 - 1 part of accelerator CZ.

[0011] In a further embodiment of the present invention, the antioxidant is antioxidant 1010.

[0012] In a further embodiment of the present invention, the antiozonant is antiozonant 4010NA.

[0013] A preparation method of a novel oil-resistant rubber comprises the following steps:

[0014] Pretreatment of raw materials: drying nano carbon black, surface-modified calcium fluoride, layered silicate, and nano calcium carbonate at 60 - 80°C for 2 - 4 hours respectively; plasticizing terpolymer fluororubber, nitrile rubber, carboxylated nitrile rubber, chloroprene rubber, and fluororubber on an open mill, setting the roll gap to 0.5 - 1 mm, and the plasticizing time to 5 - 10 minutes.

[0015] Mixing: sequentially putting the plasticized rubber into an internal mixer, adding nano carbon black, surface-modified calcium fluoride, layered silicate, nano calcium carbonate, polyisobutylene, dioctyl phthalate, and stearic acid, and mixing for 8 - 12 minutes under the conditions of a temperature of 80 - 100°C and a rotation speed of 40 - 60 r / min; adding magnesium oxide, magnesium hydroxide, zinc oxide, accelerator, sulfur, antioxidant, and antiozonant, and continuing to mix for 5 - 8 minutes under the conditions of a temperature of 100 - 120°C and a rotation speed of 40 - 60 r / min; finally adding bisphenol AF curing agent, triallyl isocyanurate, and benzyltriphenylphosphonium chloride, and mixing for 3 - 5 minutes under the conditions of a temperature of 120 - 140°C and a rotation speed of 40 - 60 r / min to obtain a mixed rubber.

[0016] Molding: vulcanizing and molding the mixed rubber on a flat vulcanizer, with a vulcanization temperature of 160 - 180°C, a vulcanization pressure of 10 - 20 MPa, and the vulcanization time determined according to the thickness of the product, generally 5 - 20 minutes, to obtain a novel oil-resistant rubber product.

[0017] A further solution of the present invention is that in the raw material pretreatment, the drying temperature of nano carbon black, surface-modified calcium fluoride, layered silicate, and nano calcium carbonate is 70 °C, and the drying time is 3 hours.

[0018] A further solution of the present invention is that in the mixing step, the first mixing temperature is 90 °C, the rotation speed is 50 r / min, and the mixing time is 10 minutes; the second mixing temperature is 110 °C, the rotation speed is 50 r / min, and the mixing time is 6 minutes; the third mixing temperature is 130 °C, the rotation speed is 50 r / min, and the mixing time is 4 minutes.

[0019] A further solution of the present invention is that in the molding step, the vulcanization temperature is 170 °C and the vulcanization pressure is 15 MPa.

[0020] Advantages of the present invention:

[0021] 1. Excellent oil resistance: In the formula, the terpolymer fluororubber and fluororubber have strong chemical stability and can effectively resist the corrosion of methanol gasoline and diesel; nitrile rubber and carboxy nitrile rubber have good tolerance to fuel organic solvents; chloroprene rubber improves the comprehensive performance. The addition of fillers such as surface-modified calcium fluoride, layered silicate, and nano calcium carbonate enhances the rubber denseness, reduces the penetration of fuel molecules, significantly improves the oil resistance, and effectively avoids problems such as performance degradation and seal failure caused by fuel corrosion.

[0022] 2. Good mechanical properties: Nano carbon black is evenly dispersed in the rubber matrix and has a strong interaction with the molecular chains, which can effectively improve the tensile strength, tear strength, and wear resistance of the rubber. Polyisobutylene and dioctyl phthalate as softeners improve the processing performance while maintaining the flexibility and elasticity of the rubber. A variety of additives work together to endow the rubber with good comprehensive mechanical properties, and can meet the various stress and deformation requirements of actual use scenarios such as automotive fuel systems and chemical pipeline seals.

[0023] 3. Excellent aging resistance: Antioxidant 1010 and antiozonant 4010NA can effectively inhibit the aging phenomenon of rubber under the action of oxidation, heat, light, etc., and extend the service life. The vulcanization system composed of accelerator DM, CZ, bisphenol AF vulcanizing agent, triallyl isocyanurate, benzyltriphenylphosphonium chloride, etc. enables the rubber to form a uniform and stable cross-linked network structure, further enhancing the aging resistance and chemical stability of the rubber, and ensuring stable and reliable performance during long-term use. Specific embodiments

[0024] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] A novel oil-resistant rubber comprises the following raw materials by weight: 10-30 parts of ternary polymerized fluororubber, 20-40 parts of nitrile rubber, 10-20 parts of carboxylated nitrile rubber, 5-15 parts of chloroprene rubber, 10-20 parts of nano carbon black, 5-10 parts of surface-modified calcium fluoride, 3-8 parts of layered silicate, 5-12 parts of nano calcium carbonate, 1-3 parts of bisphenol AF vulcanizing agent, 0.5-2 parts of triallyl triisocyanurate, 0.3-1 parts of benzyl triphenylphosphonium chloride, 5-15 parts of fluororubber, 2-6 parts of polyisobutylene, 3-8 parts of dioctyl phthalate, 0.5-2 parts of stearic acid, 2-5 parts of magnesium oxide, 3-7 parts of magnesium hydroxide, 1-3 parts of zinc oxide, 0.8-2.5 parts of accelerator, 0.2-1 parts of sulfur, 0.5-1.5 parts of antioxidant and 0.5-1.5 parts of anti-aging agent.

[0027] The accelerators are 0.5-1.5 parts of accelerator DM and 0.3-1 parts of accelerator CZ.

[0028] The advantages of the above settings are:

[0029] Synergistically promote the vulcanization reaction: Accelerator DM and accelerator CZ have different activities and mechanisms of action. The combination of the two can produce a synergistic effect. Accelerator DM can accelerate the vulcanization reaction to a certain extent, while accelerator CZ has a stronger activation effect on the vulcanization reaction, especially increasing the crosslinking density of the vulcanized rubber. The combination of the two can make the vulcanization reaction more sufficient and efficient, shorten the vulcanization time, improve production efficiency, and ensure that the rubber products can quickly and evenly reach the required degree of vulcanization during the vulcanization process.

[0030] Optimize vulcanized rubber performance: This combination helps to form a more uniform and stable cross-linked network structure. The uniform cross-linked network can give the rubber good physical and mechanical properties, such as improving the tensile strength, tear strength and wear resistance of the rubber. In an oil-resistant environment, the stable cross-linked network can effectively resist the penetration and erosion of fuel molecules, reduce the swelling and performance degradation of the rubber, and thus significantly improve the oil resistance and service life of the rubber.

[0031] Improve processing safety: Using certain accelerators alone may pose a risk of scorch during processing, that is, the rubber undergoes a vulcanization reaction prematurely before processing and forming, resulting in a decline in the quality of the product. When accelerator DM and accelerator CZ are used in combination in a specific ratio, the starting time and reaction rate of the vulcanization reaction can be adjusted, effectively reducing the scorch tendency, improving the safety and stability during the rubber processing, enabling the rubber to better maintain plasticity and fluidity during processing such as mixing and forming, and facilitating production operations.

[0032] Enhance formulation adaptability: The new oil-resistant rubber formulation contains various rubber and additive components. The combination of accelerator DM and accelerator CZ can be well adapted to other vulcanization system components such as bisphenol AF vulcanizing agent, triallyl isocyanurate, and benzyltriphenylphosphonium chloride, and they work synergistically. At the same time, it can also adapt to the characteristics of different rubber matrices such as terpolymerized fluororubber and nitrile rubber, making the entire formulation system more coordinated and stable, and ensuring that the rubber products can exhibit excellent comprehensive performance under different usage conditions.

[0033] The antioxidant is antioxidant 1010.

[0034] The advantages of the above settings are as follows:

[0035] High-efficiency antioxidant performance: Antioxidant 1010 is a hindered phenol antioxidant with multiple phenolic hydroxyl functional groups. It can capture the free radicals generated during the oxidation of rubber, interrupt the chain reaction of free radicals, and thus effectively inhibit the oxidative degradation of rubber. During the use of the new oil-resistant rubber, it will inevitably be affected by factors such as oxygen, heat, and light in the air and undergo an oxidation reaction. Antioxidant 1010 can significantly delay this process, extend the service life of the rubber product, and enable it to still maintain good physical and mechanical properties and oil resistance during long-term use.

[0036] Good compatibility: Antioxidant 1010 has good compatibility with various rubber matrices such as terpolymerized fluororubber and nitrile rubber and can be evenly dispersed in the rubber system. This ensures that the antioxidant can play an antioxidant role in all parts of the rubber, avoiding the situation of severe local oxidation, making the antioxidant performance of the rubber product more stable and uniform, and improving the overall quality and reliability.

[0037] Low volatility and extraction resistance: During the use of rubber products, especially in environments such as high temperature and contact with fuel oil, if the antioxidant is easily volatilized or extracted, its content will gradually decrease and the antioxidant effect will weaken. Antioxidant 1010 has low volatility and good extraction resistance. Even under conditions of high temperature and contact with fuel oils such as methanol gasoline and diesel, it can stably exist inside the rubber for a long time and continuously play an antioxidant role, ensuring that the antioxidant performance of the rubber product is not affected in complex usage environments.

[0038] Synergistic effect with other additives: Antioxidant 1010 can have a synergistic effect with antioxidant 4010NA and other additives in the formulation. When combined with antioxidants, it can more comprehensively resist various factors causing rubber aging, such as oxidation, ozone, heat, light, etc.; when synergistic with other additives such as the vulcanization system, it helps to stabilize the rubber molecular structure during vulcanization, enabling the rubber to form a more stable cross-linked network, further enhancing the comprehensive properties of the rubber, including oil resistance, mechanical properties, and aging resistance, etc.

[0039] The antioxidant is antioxidant 4010NA.

[0040] The advantages of the above settings are as follows:

[0041] Excellent ozone aging resistance: Antioxidant 4010NA belongs to amine antioxidants and has a strong inhibitory effect on ozone. During the use of rubber products, ozone will attack the double bonds in rubber molecules, resulting in surface cracking and performance degradation of the rubber. Antioxidant 4010NA can react with ozone preferentially, forming a protective film on the rubber surface, effectively preventing the destruction of rubber molecules by ozone, significantly extending the service life of rubber in an ozone-containing environment, especially suitable for application scenarios such as automotive fuel systems that are prone to contact with ozone, ensuring the long-term stable operation of components such as rubber seals.

[0042] Good anti-fatigue aging performance: In actual use, rubber products are constantly subjected to mechanical stresses such as stretching, compression, and bending, which easily cause fatigue aging, resulting in internal structural damage and performance reduction. Antioxidant 4010NA can effectively inhibit the free radicals generated by rubber fatigue, slow down the breakage and cross-linking of molecular chains, enhance the anti-fatigue performance of the rubber, enabling the rubber to maintain good elasticity and strength under repeated stress, and extending its service life in a dynamic stress environment.

[0043] Excellent weather resistance: In addition to ozone and mechanical stress, rubber is also affected by natural environmental factors such as light, rain, and temperature changes and ages. Antioxidant 4010NA has good weather resistance, can resist the damage of factors such as ultraviolet rays to rubber, inhibit the occurrence of photo-oxidation reactions, and can stably play an anti-aging role under different temperature conditions, ensuring that rubber products maintain stable performance in outdoor or variable climate environments and maintaining their functions such as oil resistance and sealing.

[0044] Good synergistic effect with other additives: In the new oil-resistant rubber formulation, antioxidant 4010NA can have a good synergistic effect with other additives such as antioxidant 1010. When combined with antioxidants, it can form a dual protection system of antioxidant-anti-ozone, more comprehensively inhibiting rubber aging; when synergistic with the vulcanization system, it helps to optimize the rubber cross-linked structure, improve the overall stability and comprehensive properties of the rubber, enabling each component to cooperate with each other to jointly ensure the reliability and durability of rubber products under complex working conditions and harsh environments.

[0045] A preparation method of a new type of oil-resistant rubber, comprising the following steps:

[0046] Raw material pretreatment: drying nano carbon black, surface-modified calcium fluoride, layered silicate, and nano calcium carbonate at 60 - 80 °C for 2 - 4 hours respectively; plasticizing ternary polymerization fluororubber, nitrile rubber, carboxy nitrile rubber, chloroprene rubber, and fluororubber on an open mill, setting the roll gap to 0.5 - 1 mm, and the plasticizing time to 5 - 10 minutes;

[0047] Mixing: sequentially putting the plasticized rubber into an internal mixer, adding nano carbon black, surface-modified calcium fluoride, layered silicate, nano calcium carbonate, polyisobutylene, dioctyl phthalate, and stearic acid, and mixing for 8 - 12 minutes under the conditions of a temperature of 80 - 100 °C and a rotation speed of 40 - 60 r / min; adding magnesium oxide, magnesium hydroxide, zinc oxide, accelerator, sulfur, antioxidant, and antiozonant, and continuing to mix for 5 - 8 minutes under the conditions of a temperature of 100 - 120 °C and a rotation speed of 40 - 60 r / min; finally adding bisphenol AF vulcanizing agent, triallyl isocyanurate, and benzyltriphenylphosphonium chloride, and mixing for 3 - 5 minutes under the conditions of a temperature of 120 - 140 °C and a rotation speed of 40 - 60 r / min to obtain a mixed rubber;

[0048] Molding: vulcanizing and molding the mixed rubber on a flat vulcanizer, with a vulcanization temperature of 160 - 180 °C, a vulcanization pressure of 10 - 20 MPa, and the vulcanization time determined according to the thickness of the product, generally 5 - 20 minutes, to obtain a new type of oil-resistant rubber product.

[0049] In the raw material pretreatment, the drying temperature of nano carbon black, surface-modified calcium fluoride, layered silicate, and nano calcium carbonate is 70 °C, and the drying time is 3 hours.

[0050] The advantages of the above settings are:

[0051] Effectively removing moisture: The drying temperature of 70 °C and the drying time of 3 hours can ensure that the moisture in fillers such as nano carbon black, surface-modified calcium fluoride, layered silicate, and nano calcium carbonate volatilizes sufficiently. The presence of moisture will affect the combination of fillers and the rubber matrix during the rubber mixing process, which may cause defects such as pores and bubbles in the mixed rubber, thereby reducing the density and mechanical properties of the rubber product. Thoroughly drying to remove moisture can avoid these problems and ensure the quality stability of the rubber product.

[0052] Ensure the dispersion of fillers: Appropriate drying temperature and time will not change the physical and chemical properties of fillers, maintaining their good dispersion performance. If the drying temperature is too high or the time is too long, the fillers may agglomerate and denature, affecting their uniform dispersion in the rubber matrix; if the temperature is too low or the time is insufficient, the residual moisture will affect the dispersion effect. Drying at 70°C for 3 hours can keep the fillers in a good original state, making them more easily and uniformly dispersed in the rubber matrix during the subsequent mixing process, fully exerting their functions such as strengthening and toughening, and improving the comprehensive performance of the rubber.

[0053] Avoid adverse chemical reactions: This drying condition is relatively mild, which can prevent unnecessary chemical reactions between fillers and oxygen, moisture, etc. in the air during drying. For example, the active components in some fillers may be oxidized at high temperatures, affecting their improvement effect on rubber properties. Drying at 70°C for 3 hours can not only ensure the drying effect but also avoid changes in the properties of fillers, ensuring that fillers can work synergistically with the rubber matrix and other additives normally, enabling rubber products to meet the expected performance indicators.

[0054] Improve production efficiency and stability: The standardized setting of drying temperature and time is convenient for control and operation in industrial production, ensuring the consistency of the pretreatment of each batch of raw materials, thereby improving production efficiency and the stability of product quality. Stable pretreatment conditions enable subsequent processes such as mixing and molding to proceed more stably, reducing production abnormalities and product quality fluctuations caused by fluctuations in factors such as raw material moisture, lowering production costs, and enhancing the economic benefits of enterprises.

[0055] In the mixing step, the temperature of the first mixing is 90°C, the rotation speed is 50 r / min, and the mixing time is 10 minutes; the temperature of the second mixing is 110°C, the rotation speed is 50 r / min, and the mixing time is 6 minutes; the temperature of the third mixing is 130°C, the rotation speed is 50 r / min, and the mixing time is 4 minutes.

[0056] The advantages of the above settings are as follows:

[0057] Achieve step-by-step and uniform dispersion of raw materials: In the first step, knead at 90°C and 50 r / min for 10 minutes. At this stage, the temperature is moderate and the rotation speed is stable, which can initially mix the plasticized rubber with fillers such as nano carbon black and surface-modified calcium fluoride, as well as softeners such as polyisobutylene and dioctyl phthalate. The relatively low temperature avoids premature softening and sticking of the rubber to the roller, and sufficient time ensures the initial uniform dispersion of the fillers and softeners in the rubber matrix, laying a foundation for subsequent kneading. In the second step, raise the temperature to 110°C and continue to knead at 50 r / min for 6 minutes. As the temperature rises, the plasticity of the rubber is further enhanced, which is conducive to better penetration of vulcanization activators such as magnesium oxide and magnesium hydroxide, and auxiliaries such as accelerator DM and accelerator CZ between the rubber molecular chains to achieve uniform dispersion. At the same time, the control of this temperature and time can avoid premature initiation of the vulcanization reaction by the accelerator. In the third step, knead at 130°C and 50 r / min for 4 minutes. The high temperature promotes the rapid and uniform dispersion of vulcanizing agents such as bisphenol AF vulcanizing agent and triallyl isocyanurate, completes the kneading in a short time, prevents over-kneading of the rubber, ensures uniform distribution of the vulcanizing agent in the rubber, and creates conditions for the formation of a uniform cross-linking network in subsequent vulcanization molding.

[0058] Improve the comprehensive performance of rubber: The staged and precise kneading parameter settings ensure the full dispersion and interaction of various raw materials in the rubber matrix. Uniformly dispersed fillers such as nano carbon black can effectively enhance the tensile strength and wear resistance of the rubber; reasonably dispersed softeners ensure the flexibility of the rubber; uniformly distributed vulcanization systems and auxiliaries help to form a stable and uniform cross-linking network, improving the oil resistance, aging resistance and mechanical properties of the rubber. Each raw material plays a synergistic role, making the finally prepared new oil-resistant rubber have excellent comprehensive performance and meet the actual application requirements.

[0059] Improve production efficiency and quality stability: Clear kneading temperature, rotation speed and time parameters are convenient for precise control and repeated operation in industrial production. The standardized kneading process can ensure the stable kneading quality of each batch of products, reduce the product quality differences caused by the fluctuations of the kneading process, and improve the product quality stability. At the same time, scientific kneading parameter settings avoid problems such as over-kneading or insufficient kneading, reduce rework and defective product rates, effectively improve production efficiency, reduce production costs, and enhance the competitiveness of the enterprise in the market.

[0060] Ensure production safety: This kneading method with staged temperature increase and control of rotation speed and time avoids problems such as rubber scorching and decomposition that may be caused by too high temperature, too fast rotation speed or too long kneading time, reducing the safety risks in the production process. Stable process parameters make the kneading process more controllable, reducing the probability of equipment failures and safety accidents caused by process instability, and ensuring the safe and orderly progress of production.

[0061] In the molding step, the vulcanization temperature is 170°C and the vulcanization pressure is 15 MPa.

[0062] The advantages of the above settings are as follows:

[0063] Promote the efficient formation of crosslinked structures: The vulcanization temperature of 170 °C can provide suitable reaction activation energy for vulcanization systems such as bisphenol AF vulcanizing agent and triallyl isocyanurate. At this temperature, the vulcanizing agent can quickly and fully react with the rubber molecular chains to form a stable crosslinked network. Compared with lower temperatures, 170 °C can significantly shorten the vulcanization reaction time and improve production efficiency; compared with too high temperatures, it can avoid problems such as excessive cracking of rubber molecular chains and decomposition of additives, ensuring the integrity and uniformity of the crosslinked structure, and endowing the rubber with good physical and mechanical properties and oil resistance.

[0064] Enhance the density and strength of the rubber: The vulcanization pressure of 15 MPa helps to expel the gas generated during the vulcanization of the mixed rubber, avoiding defects such as pores and bubbles inside the product, thereby improving the density of the rubber product. At the same time, this pressure can promote the close arrangement of rubber molecular chains during crosslinking, enhance the intermolecular force, and further improve the mechanical properties such as tensile strength and tear strength of the rubber. In oil-resistant application scenarios, the dense structure can effectively block the penetration of fuel molecules, reduce the swelling of the rubber, and maintain its sealing performance and use stability.

[0065] Ensure the synergistic effect of each component in the formulation: These temperature and pressure conditions are highly compatible with various components in the new oil-resistant rubber formulation. At 170 °C and 15 MPa, various rubber matrices such as ternary polymerization fluororubber and nitrile rubber can be fully fused, and components such as fillers and additives can also better play a synergistic effect. For example, reinforcing fillers such as nano carbon black can be more closely combined with the rubber matrix under this condition to enhance the reinforcing effect; additives such as antioxidants and anti-aging agents can be evenly distributed and stably present in the crosslinked network in a suitable vulcanization environment, continuously playing antioxidant and anti-aging roles, and improving the comprehensive performance and service life of the rubber product.

[0066] Meet the requirements of industrial production: The vulcanization parameters of 170 °C and 15 MPa are within the normal working range of existing industrial vulcanization equipment, without the need for special equipment or complex process adjustments, facilitating large-scale industrial production. Stable process parameters are easy to control and repeat, which can ensure the quality consistency of each batch of products, reduce the risk of process fluctuations during production, improve production efficiency and product qualification rate, help enterprises reduce production costs, and enhance market competitiveness.

[0067] Example 2

[0068] A new type of oil-resistant rubber and its preparation method:

[0069] Raw material formula: 20 parts of terpolymerized fluororubber, 30 parts of nitrile rubber, 15 parts of carboxylated nitrile rubber, 10 parts of chloroprene rubber, 15 parts of nano carbon black, 8 parts of surface-modified calcium fluoride, 6 parts of layered silicate, 8 parts of nano calcium carbonate, 2 parts of bisphenol AF vulcanizing agent, 1.5 parts of triallyl isocyanurate, 0.8 part of benzyltriphenylphosphonium chloride, 10 parts of fluororubber, 4 parts of polyisobutylene, 6 parts of dioctyl phthalate, 1 part of stearic acid, 4 parts of magnesium oxide, 5 parts of magnesium hydroxide, 2 parts of zinc oxide, 0.8 part of accelerator, 0.5 part of sulfur, 1 part of antioxidant, 1 part of anti-aging agent.

[0070] Preparation method:

[0071] Pretreatment of raw materials: Place nano carbon black, surface-modified calcium fluoride, layered silicate, and nano calcium carbonate in a drying oven at 70 °C for 3 hours; put terpolymerized fluororubber, nitrile rubber, carboxylated nitrile rubber, chloroprene rubber, and fluororubber into an open mill, adjust the roll gap to 0.8 mm, and plasticate for 8 minutes.

[0072] Mixing: Add the plasticated rubber to an internal mixer in sequence, add nano carbon black, surface-modified calcium fluoride, layered silicate, nano calcium carbonate, polyisobutylene, dioctyl phthalate, and stearic acid, and mix at 90 °C and 50 r / min for 10 minutes; then add magnesium oxide, magnesium hydroxide, zinc oxide, accelerator, sulfur, antioxidant, and anti-aging agent, and continue to mix at 110 °C and 50 r / min for 6 minutes; finally, add bisphenol AF vulcanizing agent, triallyl isocyanurate, and benzyltriphenylphosphonium chloride, and mix at 130 °C and 50 r / min for 4 minutes to obtain a mixed rubber.

[0073] Molding: Put the mixed rubber into a flat vulcanizer, set the vulcanization temperature at 170 °C, the vulcanization pressure at 15 MPa, and according to the thickness of the product, set the vulcanization time at 8 minutes to obtain a new oil-resistant rubber product.

[0074] Example 3

[0075] A new oil-resistant rubber and its preparation method:

[0076] Raw material formula: 25 parts of terpolymerized fluororubber, 25 parts of nitrile rubber, 18 parts of carboxylated nitrile rubber, 12 parts of chloroprene rubber, 18 parts of nano carbon black, 9 parts of surface-modified calcium fluoride, 7 parts of layered silicate, 10 parts of nano calcium carbonate, 2.5 parts of bisphenol AF vulcanizing agent, 1.8 parts of triallyl isocyanurate, 0.9 part of benzyltriphenylphosphonium chloride, 12 parts of fluororubber, 5 parts of polyisobutylene, 7 parts of dioctyl phthalate, 1.5 parts of stearic acid, 4.5 parts of magnesium oxide, 6 parts of magnesium hydroxide, 2.5 parts of zinc oxide, 1.9 parts of accelerator, 0.8 part of sulfur, 1.2 parts of antioxidant, 1.2 parts of anti-aging agent.

[0077] Preparation method

[0078] Raw material pretreatment: Similarly, fillers such as nano carbon black are dried at 70 °C for 3 hours, and various rubbers are plasticized on an open mill at a roll gap of 0.8 mm for 8 minutes.

[0079] Mixing: The plasticized rubber and raw materials are added to an internal mixer in sequence. In the first step, it is mixed at 90 °C and 50 r / min for 10 minutes; in the second step, the temperature is raised to 110 °C and kept at 50 r / min for 6 minutes; in the third step, the temperature is raised to 130 °C and mixed at 50 r / min for 4 minutes to obtain the mixed rubber.

[0080] Molding: In a flat vulcanizer, at a vulcanization temperature of 170 °C and a vulcanization pressure of 15 MPa, according to the thickness of the product, the vulcanization time is set to 12 minutes to complete the preparation of the new oil-resistant rubber product.

[0081] Experimental verification

[0082] I. Experimental purpose

[0083] Perform performance tests on the new oil-resistant rubbers prepared in Example 2 and Example 3 to verify whether they achieve the expected effects in terms of oil resistance, mechanical properties, aging resistance, etc., and compare them with traditional oil-resistant rubbers to highlight the advantages of the products of the present invention.

[0084] II. Experimental materials and equipment

[0085] (I) Experimental materials

[0086] The new oil-resistant rubber products prepared in Example 2.

[0087] The new oil-resistant rubber products prepared in Example 3.

[0088] Traditional nitrile rubber products (Comparative Example 1).

[0089] Methanol gasoline (methanol content 15%).

[0090] 0# diesel.

[0091] (II) Experimental equipment

[0092] Constant temperature oil bath.

[0093] Electronic balance (accuracy 0.0001 g).

[0094] Tensile testing machine.

[0095] Aging test chamber.

[0096] Vernier caliper.

[0097] III. Experimental method

[0098] (I) Oil resistance performance test

[0099] Three specimens each with dimensions of 50 mm × 25 mm × 2 mm were cut from the rubber products of Example 2, Example 3, and the traditional nitrile rubber product of Comparative Example 1 respectively.

[0100] The initial length, width, and thickness of the specimens were measured with a vernier caliper, and the initial volume was calculated. The initial weight was weighed with an electronic balance.

[0101] The specimens were respectively placed in sealed containers filled with methanol gasoline and diesel, and immersed in a constant temperature oil bath at 70 °C for 72 hours.

[0102] The specimens were taken out, and the residual liquid on the surface was blotted dry with filter paper. Then the length, width, and thickness of the specimens were measured again, the volume after immersion was calculated, and the weight was weighed.

[0103] The volume change rate and weight change rate were calculated.

[0104] (2) Mechanical property test

[0105] According to the standard of GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", dumbbell-shaped specimens were cut from each rubber product.

[0106] Using a tensile testing machine, the tensile speed was set at 500 mm / min, and a tensile test was carried out on the specimens. Data such as tensile strength, elongation at break, and tear strength were recorded. Each sample was tested 5 times and the average value was taken.

[0107] (3) Aging resistance property test

[0108] Specimens with dimensions of 50 mm × 25 mm × 2 mm were cut from each rubber product.

[0109] The specimens were placed in an aging test chamber, with the temperature set at 100 °C and the aging time at 72 hours.

[0110] After aging, the specimens were taken out and left to recover at room temperature for 24 hours.

[0111] Again using the tensile testing machine, according to the method of mechanical property test, the tensile strength and elongation at break of the specimens after aging were measured, and the tensile strength retention rate and elongation at break retention rate were calculated.

[0112] IV. Experimental results and analysis

[0113] (1) Test results of oil resistance property

[0114] Sample Immersion medium Volume change rate (%) Weight change rate (%) Example 2 Methanol gasoline 3.0 2.0 Example 2 Diesel 2.3 1.6 Example 3 Methanol gasoline 2.6 1.7 Example 3 Diesel 2.1 1.4 Comparative Example 1 Methanol gasoline 8.5 6.2 Comparative Example 1 Diesel 5.8 4.3

[0115] Analysis: The volume change rate and weight change rate of the novel oil-resistant rubber prepared in Example 2 and Example 3 in methanol gasoline and diesel are significantly lower than those of traditional nitrile rubber, indicating that the novel oil-resistant rubber has more excellent oil resistance and can effectively resist the erosion of fuel.

[0116] (2) Test results of mechanical properties

[0117] Sample Tensile strength (MPa) Elongation at break (%) Tear strength (kN / m) Example 2 19 480 48 Example 3 21 520 52 Comparative Example 1 15 400 40

[0118] Analysis: The tensile strength, elongation at break and tear strength of the novel oil-resistant rubber are better than those of traditional nitrile rubber, indicating that the formulation and preparation process of the present invention endow the rubber with better mechanical properties and can meet the mechanical requirements in actual use.

[0119] (3) Test results of aging resistance performance

[0120] Sample Tensile strength retention rate (%) Elongation at break retention rate (%) Example 2 86 82 Example 3 89 84 Comparative Example 1 75 70

[0121] Analysis: After the aging test, the tensile strength retention rate and elongation at break retention rate of the novel oil-resistant rubber in Example 2 and Example 3 are higher than those of traditional nitrile rubber, indicating that the novel oil-resistant rubber has better aging resistance and longer service life.

[0122] V. Experimental conclusions

[0123] Through the tests of oil resistance, mechanical properties and aging resistance of the novel oil-resistant rubber prepared in Example 2 and Example 3 and comparison with traditional nitrile rubber, it can be seen that the novel oil-resistant rubber prepared by the present invention performs excellently in various performance indicators, can effectively withstand the corrosion of methanol gasoline and diesel, and has good application prospects.

[0124] The examples given in the present invention are illustrative rather than restrictive of the embodiments. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here, and the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A new type of oil-resistant rubber, characterized in that, The raw materials, by weight parts, include: 10 - 30 parts of ternary polymerization fluororubber, 20 - 40 parts of nitrile rubber, 10 - 20 parts of carboxyl nitrile rubber, 5 - 15 parts of chloroprene rubber, 10 - 20 parts of nano carbon black, 5 - 10 parts of surface - modified calcium fluoride, 3 - 8 parts of layered silicate, 5 - 12 parts of nano calcium carbonate, 1 - 3 parts of bisphenol AF vulcanizing agent, 0.5 - 2 parts of triallyl isocyanurate, 0.3 - 1 part of benzyl triphenyl phosphonium chloride, 5 - 15 parts of fluororubber, 2 - 6 parts of polyisobutene, 3 - 8 parts of dioctyl phthalate, 0.5 - 2 parts of stearic acid, 2 - 5 parts of magnesium oxide, 3 - 7 parts of magnesium hydroxide, 1 - 3 parts of zinc oxide, 0.8 - 2.5 parts of accelerator, 0.2 - 1 part of sulfur, 0.5 - 1.5 parts of antioxidant, and 0.5 - 1.5 parts of antiozonant.

2. A novel oil-resistant rubber according to claim 1, characterized in that, The raw materials, by weight parts, are: 20 parts of ternary polymerization fluororubber, 30 parts of nitrile rubber, 15 parts of carboxyl nitrile rubber, 10 parts of chloroprene rubber, 15 parts of nano carbon black, 8 parts of surface - modified calcium fluoride, 6 parts of layered silicate, 8 parts of nano calcium carbonate, 2 parts of bisphenol AF vulcanizing agent, 1.5 parts of triallyl isocyanurate, 0.8 part of benzyl triphenyl phosphonium chloride, 10 parts of fluororubber, 4 parts of polyisobutene, 6 parts of dioctyl phthalate, 1 part of stearic acid, 4 parts of magnesium oxide, 5 parts of magnesium hydroxide, 2 parts of zinc oxide, 0.8 part of accelerator, 0.5 part of sulfur, 1 part of antioxidant, and 1 part of antiozonant.

3. A novel oil-resistant rubber according to claim 1, characterized in that, The accelerator is 0.5 - 1.5 parts of accelerator DM and 0.3 - 1 part of accelerator CZ.

4. A novel oil-resistant rubber according to claim 1, characterized in that, The antioxidant is antioxidant 1010.

5. A novel oil-resistant rubber according to claim 1, characterized in that, The antiozonant is antiozonant 4010NA.

6. A preparation method of the novel oil-resistant rubber according to any one of claims 1-5, characterized in that, It includes the following steps: Pretreatment of raw materials: Dry nano carbon black, surface - modified calcium fluoride, layered silicate, and nano calcium carbonate at 60 - 80 °C for 2 - 4 hours respectively; Plasticate ternary polymerization fluororubber, nitrile rubber, carboxyl nitrile rubber, chloroprene rubber, and fluororubber on an open mill, set the roll gap to 0.5 - 1 mm, and the plasticating time to 5 - 10 minutes. Mixing: Put the plasticated rubbers into an internal mixer in sequence, add nano carbon black, surface - modified calcium fluoride, layered silicate, nano calcium carbonate, polyisobutene, dioctyl phthalate, and stearic acid, and mix at a temperature of 80 - 100 °C and a rotational speed of 40 - 60 r / min for 8 - 12 minutes; Add magnesium oxide, magnesium hydroxide, zinc oxide, accelerator, sulfur, antioxidant, and antiozonant, and continue to mix at a temperature of 100 - 120 °C and a rotational speed of 40 - 60 r / min for 5 - 8 minutes; Finally, add bisphenol AF vulcanizing agent, triallyl isocyanurate, and benzyl triphenyl phosphonium chloride, and mix at a temperature of 120 - 140 °C and a rotational speed of 40 - 60 r / min for 3 - 5 minutes to obtain the mixed rubber. Molding: Vulcanize and mold the mixed rubber on a flat vulcanizer, the vulcanization temperature is 160 - 180 °C, the vulcanization pressure is 10 - 20 MPa, and the vulcanization time is determined according to the thickness of the product, generally 5 - 20 minutes, to obtain the new oil - resistant rubber product.

7. The preparation method of a novel oil-resistant rubber according to claim 6, characterized in that, In the pretreatment of the raw materials, the drying temperature of nano carbon black, surface-modified calcium fluoride, layered silicate, and nano calcium carbonate is 70 °C, and the drying time is 3 hours.

8. The preparation method of a novel oil-resistant rubber according to claim 6, characterized in that, In the mixing step, the temperature of the first mixing is 90 °C, the rotation speed is 50 r / min, and the mixing time is 10 minutes; the temperature of the second mixing is 110 °C, the rotation speed is 50 r / min, and the mixing time is 6 minutes; the temperature of the third mixing is 130 °C, the rotation speed is 50 r / min, and the mixing time is 4 minutes.

9. The preparation method of a novel oil-resistant rubber according to claim 6, characterized in that, In the molding step, the vulcanization temperature is 170 °C, and the vulcanization pressure is 15 MPa.