Ethylene-propylene-diene monomer rubber working at high temperature of 180 DEG C, and preparation process and application thereof

Abstract

The invention discloses an ethylene-propylene-diene monomer rubber working at a high temperature of 180 DEG C. The ethylene-propylene-diene monomer rubber has the characteristics of excellent insulativity, high and low temperature resistance, acid and alkali resistance, weather resistance, high elasticity and flexibility, has more excellent thermal stability and ultraviolet resistance, and has lower wet permeability than natural rubber, butyronitrile rubber and silica gel; the invention also provides a preparation process aiming at the formula, the process is adopted for control, and a two-stage method is adopted for rubber mixing, so that the advantages of each component in the formula are further exerted, and the temperature resistance, the sealing property and the strength of the ethylene propylene diene monomer are improved; the ethylene propylene diene monomer provided by the invention can be widely applied to static sealing products and can be used within the range of 180 DEG C or below, the technical problem that fluororubber with higher cost has to be adopted when the temperature exceeds 165 DEG C is solved, and the ethylene propylene diene monomer has a wide application prospect. The invention belongs to the technical field of rubber processing.

Description

Technical Field

[0001] This application belongs to the technical field of rubber processing, and in particular relates to ethylene propylene diene monomer (EPDM) rubber working at 180°C, a preparation process and applications thereof. Background Art

[0002] Rubber sealing rings are used for sealing in static sealing products, and some are used in high-temperature environments, such as gaskets for plate heat exchangers, engine seals, high-temperature pipelines and valves, high- and low-voltage wires and cables, and electrical insulation parts, etc. The gasket for a plate heat exchanger is a key component for sealing the gap between plate sheets, which can ensure heat exchange efficiency and prevent medium leakage. When selecting, working pressure, temperature, and medium compatibility need to be considered. As an indispensable high-efficiency heat exchange device in modern industry, the precision and sealing performance of the internal structure of a plate heat exchanger are directly related to heat exchange efficiency and operation safety. In practical applications, it is crucial to select a suitable gasket for a plate heat exchanger. First, the material of the gasket needs to be determined according to the properties of the working medium (such as temperature, pressure, corrosiveness). Second, the specific working conditions of the heat exchanger (such as flow rate, pressure fluctuation range) need to be considered to select a gasket with sufficient elasticity and compensation ability. Finally, the convenience of installation and maintenance of the gasket also needs to be concerned to ensure the long-term stable operation of the heat exchanger.

[0003] According to different materials, static sealing products can be divided into rubber gaskets, metal gaskets, and composite material gaskets, etc. Rubber gaskets have good elasticity and sealing performance and are suitable for most heat exchange occasions under normal temperature and pressure conditions. Metal gaskets have higher pressure resistance and high-temperature resistance and are suitable for heat exchange processes with high temperature, high pressure, or corrosive media. Composite material gaskets combine the advantages of multiple materials to meet the requirements under different special working conditions. Currently, the highest applicable temperature of the sealing material made of ethylene propylene diene monomer (EPDM) rubber is 165°C. If it is necessary to use it in a higher temperature environment, the sealing material needs to be replaced with fluororubber, and the cost of fluororubber is about 10 - 15 times that of this product. Therefore, it is of great significance to develop an ethylene propylene diene monomer (EPDM) rubber that can withstand higher temperatures. Summary of the Invention

[0004] The purpose of the implementation of this application is to provide an ethylene propylene diene monomer (EPDM) rubber working at 180°C, a preparation process and applications thereof, so as to solve the technical problem that the existing ethylene propylene diene monomer (EPDM) rubber can withstand a maximum temperature of 165°C and cannot be used in a higher temperature environment.

[0005] To achieve the above object, the technical solution adopted in this application is as follows: Provide an ethylene propylene diene monomer (EPDM) rubber that can work at a high temperature of 180°C. By mass, it specifically includes the following components: 108 parts of EPDM rubber, 70 - 90 parts of carbon black, 3 - 5 parts of metal oxide, 0.5 - 1.5 parts of stearic acid, 1 - 3 parts of antioxidant, 2 - 4 parts of polyethylene glycol, 4 - 6 parts of silicon carbide, 2.25 - 5.15 parts of crosslinking agent, and 1 - 1.4 parts of co-crosslinking agent;

[0006] Furthermore, the addition of carbon black can significantly improve the strength and hardness of the sealant, which benefits from the high tensile strength and hardness characteristics of carbon black itself; secondly, carbon black can also greatly improve the wear resistance of the sealant and extend its service life, which is mainly attributed to the excellent wear resistance and aging resistance of carbon black; in addition, carbon black also plays an important role in improving the processing performance of the sealant. It can effectively adjust the rheological properties and viscosity of the sealant, making processing and construction more convenient;

[0007] Silicon carbide has characteristics such as high hardness, high wear resistance, high thermal stability, high thermal conductivity, and chemical stability. Its thermal conductivity is significantly higher than that of silicon and gallium arsenide, especially excellent in high-temperature environments. It can maintain its physical and mechanical properties at a high temperature exceeding 1500°C, with a thermal conductivity as high as 120 W / m·K and a low thermal expansion coefficient (about 4.2*10^ -6 / K), which helps to reduce material failure caused by temperature changes and has extremely high tolerance to most acids, alkalis, and oxidants, and can maintain integrity even in extreme chemical environments. It can increase the high-temperature resistance of the rubber. In a continuous high-temperature environment, it helps to quickly transfer the temperature inside the rubber to the outside and release it, enabling the product to be used in a high-temperature environment.

[0008] In one of the embodiments,

[0009] The EPDM rubber includes EPDM rubber particles and liquid EPDM rubber; the EPDM rubber particles include LANXESS 2650C, Sinopec Mitsui 2060M, and Sinopec Mitsui 3090EM; the liquid EPDM rubber is EB15.

[0010] In one of the embodiments,

[0011] The mass ratio of the EPDM rubber particles to the liquid EPDM rubber is 12.5:1.

[0012] In one of the embodiments,

[0013] The mass ratio of LANXESS 2650C, Sinopec Mitsui 2060M, and Sinopec Mitsui 3090EM is 2:2:1.

[0014] In one of the embodiments,

[0015] The metal oxides include zinc oxide and magnesium oxide; the mass ratio of the zinc oxide to the magnesium oxide is 1:1;

[0016] The anti-aging agents include anti-aging agent 4020 and anti-aging agent RD, and the mass ratio of the anti-aging agent 4020 to the anti-aging agent RD is 1:1;

[0017] Furthermore, for the continuous high-temperature use of the sealing product, the combined use of anti-aging agent 4020 and anti-aging agent RD takes into account both static thermal oxygen aging and mechanical fatigue, and can economically and efficiently expand the protection range;

[0018] The polyethylene glycol is one of polyethylene glycol-4000, polyethylene glycol-8000 or polyethylene glycol-10000. Preferably, the polyethylene glycol is polyethylene glycol-4000;

[0019] Furthermore, rubber, as an elastic material, is usually hard and brittle. By adding PEG-4000, the rubber can become softer and more extensible, improving its processability. PEG-4000 can penetrate into the rubber matrix and interact with rubber chains, thereby reducing the intermolecular forces between rubber chains and making the rubber easier to deform. Secondly, it can also improve the fatigue resistance of the rubber. The rubber is prone to fatigue failure during use, shortening the life of the material. It can form a cross-linked structure in the rubber matrix to increase the strength and toughness of the rubber, thereby improving the fatigue resistance of the rubber. In addition, it can also improve the heat resistance of the rubber. The rubber is prone to softening at high temperatures, losing its elasticity and durability. Adding PEG-4000 can form a cross-linked structure to increase the thermal stability and heat resistance of the rubber. PEG-4000 has a relatively high melting point and thermal decomposition temperature, which can improve the heat resistance of the rubber and extend its service life. In addition, it can also improve the chemical resistance of the rubber. The rubber usually comes into contact with various chemical substances and is prone to chemical reactions, resulting in rubber damage. PEG-4000 can react with active molecules in the rubber matrix to form a stable structure, improving the chemical resistance of the rubber and preventing the rubber from being corroded by chemical substances. Finally, it can also improve the adhesion performance of the rubber. The rubber usually needs to be bonded to other materials and is prone to adhesion failure during use. Adding PEG-4000 can form a protective film on the surface of the rubber, enhancing the adhesion between the rubber and other materials and improving the bonding strength and durability.

[0020] In one embodiment,

[0021] The co-crosslinking agent is one of TAIC, TMPTMA or TAC. Preferably, the co-crosslinking agent is TAIC; the crosslinking agent includes bis-25 and BIPB, and the mass ratio of the bis-25 to the BIPB is 1.15:1.

[0022] The present application also provides a preparation process for ethylene propylene diene monomer (EPDM) rubber that can work at a high temperature of 180°C, which is used to produce the EPDM rubber as described in any of the above embodiments. The specific steps are as follows:

[0023] (I) Batching: Weigh the raw and auxiliary materials to be used according to the formula table;

[0024] (II) First-stage rubber mixing: Mix the EPDM rubber, then add the minor ingredients for mixing, and then add carbon black for rubber mixing. After hanging the sheet and pouring the rubber, the sheet is taken out to obtain the first-stage rubber;

[0025] (III) Second-stage rubber mixing: After the first-stage rubber is parked for 24 hours, part of it is put into the internal mixer, and then the cross-linking agent is added. Then the remaining first-stage rubber is put in for rubber mixing and discharging to obtain the finished EPDM rubber.

[0026] In one of the embodiments,

[0027] The first-stage rubber mixing in step (II) is specifically as follows: The rubber is put into the internal mixer at a speed of 40 r / min and the upper plug pressure of 6 Mpa. After mixing for 40 s, the minor ingredients are added, and the speed is reduced to 30 r / min. After continuing to mix for 30 s, carbon black is added. When the temperature reaches 130°C, the plug is lifted and maintained for 15 s. The rubber is mixed until the temperature reaches 155°C and then discharged. After the rubber is discharged to the open mill, the thickness of the rubber sheet is maintained at 8 - 10 mm, and the sheet is hung and the rubber is poured for 3 min.

[0028] In one of the embodiments,

[0029] The second-stage rubber mixing in step (III) is specifically as follows: After the first-stage rubber is parked for 24 hours, the speed of the internal mixer is 25 - 30 r / min and the upper plug is 6 Mpa. 2 / 3 of the first-stage rubber is put into the internal mixer, and then the cross-linking agent is added. Then the remaining 1 / 3 of the first-stage rubber is put in. When the temperature reaches 75°C, 85°C, and 95°C respectively, the plug is lifted, and the rubber is discharged at 105°C to obtain the finished EPDM rubber.

[0030] The present application also provides an application of the EPDM rubber that can work at a high temperature of 180°C. The finished EPDM rubber prepared according to the above preparation process is used for static sealing products with a temperature within 180°C.

[0031] The present application provides an ethylene propylene diene monomer (EPDM) rubber that can work at a high temperature of 180°C. Instead of using a single type of rubber, through the test of compression set, the long-term reliability after blending is verified. It has excellent insulation properties, resistance to high and low temperatures, acids and alkalis, weather resistance, high elasticity, and flexibility. It has more outstanding thermal stability and anti-ultraviolet properties, and its moisture permeability is lower than that of natural rubber, nitrile rubber, and silica gel. The addition of carbon black significantly improves the strength and hardness of the sealant, greatly enhances the wear resistance of the sealant, and improves the processing performance of the sealant. PEG-4000 can form a protective film on the rubber surface, enhance the adhesion between the rubber and other materials, and improve the bonding strength and durability. Silicon carbide can increase the high-temperature resistance of the rubber, enabling the product to be used in high-temperature environments. The use of antioxidant 4020 and antioxidant RD concurrently takes into account both static thermal oxygen aging and mechanical fatigue, and can economically and efficiently expand the protection range. The present application also provides a preparation process for the above formula. By controlling this process and using a two-stage rubber mixing method, the advantages of each component in the formula are further exerted, and the temperature resistance, sealing performance, and strength of the EPDM rubber are improved. The EPDM rubber provided by the present application can be widely used in static sealing products and can be used within the range below 180°C, solving the technical problem that when the temperature exceeds 165°C, it is necessary to use more expensive fluororubber, and has broad application prospects. Detailed Embodiments

[0032] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present application clearer and more understandable, the present application is further described in detail. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0033] Example 1

[0034] An ethylene propylene diene monomer (EPDM) rubber that can work at a high temperature of 180°C, by mass, specifically includes the following components: 108 parts of EPDM rubber, among which 40 parts are Lanxess 2650C, 40 parts are Sinopec Mitsui 2060M, 20 parts are Sinopec Mitsui 3090EM, and 8 parts are EB15; 80 parts of carbon black; 3 - 5 parts of metal oxide, among which 2 parts are zinc oxide and 2 parts are magnesium oxide; 1 part of stearic acid; 2 parts of antioxidant, among which 1 part is antioxidant 4020 and 1 part is antioxidant RD; 3 parts of polyethylene glycol - 4000; 5 parts of silicon carbide; 1.2 parts of TAIC; 3.0 parts of crosslinking agent, among which 1.6 parts are bis - 25 and 1.4 parts are BIPB.

[0035] Specifically, the properties of each component in the EPDM rubber are shown in Table 1.

[0036] Table 1 Comparison of the properties of four different rubbers

[0037] Name Ethylene content (%) ENB content (%) Whether oil-filled Lanxess 2650C 46 6 No Sinopec Mitsui 2060M 55 2.3 No Sinopec Mitsui 3090EM 49.5 4.3 Yes (10 parts) EB15 66 4.6 -

[0038] Example 2

[0039] The difference between this example and Example 1 is that the mass parts of carbon black are 70 parts, zinc oxide is 1.5 parts, magnesium oxide is 1.5 parts, stearic acid is 0.5 part, antioxidant is 1 part, among which antioxidant 4020 is 0.5 part, antioxidant RD is 0.5 part, polyethylene glycol - 4000 is 2 parts, silicon carbide is 4 parts, TAIC is 1 part, crosslinking agent is 2.25 parts, among which bis - 25 is 1.15 parts and BIPB is 1 part.

[0040] Example 3

[0041] The difference between this example and Example 1 is that the mass parts of carbon black are 90 parts, zinc oxide is 2.5 parts, magnesium oxide is 2.5 parts, stearic acid is 1.5 parts, antioxidant is 3 parts, among which antioxidant 4020 is 1.5 part, antioxidant RD is 1.5 part, polyethylene glycol - 4000 is 4 parts, silicon carbide is 6 parts, TAIC is 1.4 parts, crosslinking agent is 5.15 parts, among which bis - 25 is 2.75 parts and BIPB is 2.4 parts.

[0042] Example 4

[0043] A preparation process of ethylene - propylene - diene monomer rubber working at 180 °C specifically includes the following steps:

[0044] (1). Batching: Weigh Lanxess 2650C, Sinopec Mitsui 2060M, Sinopec Mitsui 3090EM, EB15, carbon black, zinc oxide, magnesium oxide, stearic acid, antioxidant 4020, antioxidant RD, polyethylene glycol - 4000, silicon carbide, TAIC, bis - 25, BIPB respectively according to the formula of Example 1;

[0045] (2). First - stage rubber mixing: Mix Lanxess 2650C, Sinopec Mitsui 2060M, Sinopec Mitsui 3090EM, EB15, put them into an internal mixer with a rotation speed of 40 r / min and an upper ram pressure of 6 Mpa, mix for 40 s, then add small materials (the small materials include zinc oxide, magnesium oxide, stearic acid, antioxidant 4020, antioxidant RD, polyethylene glycol - 4000, silicon carbide, TAIC), and the rotation speed is reduced to 30 r / min; continue to mix for 30 s, add carbon black for rubber mixing, when the temperature reaches 130 °C, lift the ram and keep it for 15 s, and mix the rubber until discharging at 155 °C; after the rubber is discharged to an open mill, keep the thickness of the rubber sheet at 8 - 10 mm, hang the sheet and turn the rubber for 3 min to obtain the first - stage rubber;

[0046] (3). Secondary rubber mixing: After the primary rubber is stored for 24 h, the rotational speed of the internal mixer is 25 - 30 r / min, and the upper plug is at 6 Mpa. After 2 / 3 of the primary rubber is put into the internal mixer, the crosslinking agents bis - 25 and BIPB are added, and then the remaining 1 / 3 of the primary rubber is put in. When the rubber mixing reaches 75 °C, 85 °C, and 95 °C respectively, the plug is lifted, and the discharge is at 105 °C to obtain the finished ethylene - propylene - diene monomer (EPDM) rubber.

[0047] Example 5

[0048] The finished EPDM rubber prepared in Example 4 is used for the production of the gaskets of plate heat exchangers. The specific steps are as follows:

[0049] Forming and vulcanizing the finished EPDM rubber: The finished EPDM rubber is plasticized through a die by an extruder into a formed rubber strip with a specific diameter and shape. The temperature of the extruder is set at 90 °C; the formed rubber strip is covered with an opaque plastic cloth and stored for 12 h before being vulcanized twice; the parked formed rubber strips are sequentially placed into the vulcanization mold. The joint is in a lapped manner, with a joint length of 1 - 2 cm. The vulcanizer temperature is 180 °C, the pressure is 10 Mpa, and the vulcanization time is 180 s for the first vulcanization. After vulcanization, the finished product has its burrs removed; the rubber strips after the first vulcanization are stored for 4 h and placed flat on the secondary vulcanization cart. The oven vulcanizes the rubber strips under the conditions of 165 °C for 2.5 h to obtain the gaskets of plate heat exchangers; the gaskets of plate heat exchangers are tested, and the results are shown in Table 2:

[0050] Table 2 Performance test results

[0051]

[0052]

[0053] Example 6

[0054] The difference between this example and Example 1 is that polyethylene glycol - 4000 is replaced by polyethylene glycol - 8000, and TAIC is replaced by TMPTMA, with the remaining operations being the same.

[0055] Example 7

[0056] The difference between this example and Example 1 is that polyethylene glycol - 4000 is replaced by polyethylene glycol - 10000, and TAIC is replaced by TAC, with the remaining operations being the same.

[0057] In one embodiment, the finished ethylene propylene diene monomer (EPDM) rubber prepared in Example 4 can also be used in the automotive industry. In automobile manufacturing, EPDM seals are commonly used to manufacture high-temperature components, such as engine seals, radiator pipes, fuel system seals, etc.; these components need to withstand high-temperature and high-pressure environments, and the high-temperature resistance of EPDM can ensure the safe and stable operation of automobiles; its production method can be adjusted according to the use environment, which is prior art and will not be elaborated here.

[0058] In one embodiment, the finished ethylene propylene diene monomer (EPDM) rubber prepared in Example 4 can also be used in the petrochemical industry. In petrochemical production, EPDM seals can be used to manufacture components such as pipes and valves that are corrosion-resistant and high-temperature-resistant. These components need to withstand high temperatures, high pressures, and the erosion of corrosive media, and the excellent properties of EPDM make it an ideal choice; its production method can be adjusted according to the use environment, which is prior art and will not be elaborated here.

[0059] In one embodiment, the finished ethylene propylene diene monomer (EPDM) rubber prepared in Example 4 can also be used in the electrical and electronic industries. The electrical insulation performance of EPDM makes it an ideal choice in the electrical and electronic industries. It can be made into high- and low-voltage wire and cable and electrical insulation parts to ensure the safety and performance of electrical equipment; its production method can be adjusted according to the use environment, which is prior art and will not be elaborated here.

[0060] In one embodiment, the finished ethylene propylene diene monomer (EPDM) rubber prepared in Example 4 can also be used in industrial equipment and pipelines. In industrial equipment and pipeline systems, EPDM seals are widely used in the static and dynamic seals of equipment such as pumps, valves, flange connections, and compressors. Its chemical resistance and temperature resistance enable it to maintain a stable sealing effect in the harsh environments of industries such as chemical engineering, pharmaceuticals, and food processing; its production method can be adjusted according to the use environment, which is prior art and will not be elaborated here.

[0061] The present application provides an ethylene propylene diene monomer (EPDM) rubber that can work at a high temperature of 180°C. The rubber is composed of a mixture of Lanxess 2650C, Mitsui Chemicals (Sinopec) 2060M, Mitsui Chemicals (Sinopec) 3090EM, and EB15, rather than a single-specification rubber. The combination of Lanxess 2650C and Mitsui Chemicals (Sinopec) 2060M can achieve a balance among processability, heat resistance, and elasticity. The addition of Mitsui Chemicals (Sinopec) 3090EM further improves the physical properties and tear resistance of the product. The addition of liquid EPDM EB15 can improve the compatibility caused by different ENB contents of the three rubbers, can replace part of the high-molecular-weight EPDM, effectively reduce the viscosity of the mixed rubber, thereby improving its processing performance and reducing waste generation, while not significantly reducing its physical and mechanical properties. Through the test of compression set, the long-term reliability after blending is verified. The mixture of multiple rubbers is mainly a terpolymer of ethylene, propylene, and non-conjugated diene, and has the characteristics of excellent insulation, high and low temperature resistance, acid and alkali resistance, weather resistance, high elasticity, and softness. In terms of vulcanization characteristics, it can be vulcanized by peroxides, showing more excellent thermal stability and anti-ultraviolet characteristics than liquid polyisoprene and polybutadiene, and performing well in terms of water permeability. Its water permeability is significantly lower than that of natural rubber, nitrile rubber, and silica gel, only being 1 / 5, 1 / 10, and 1 / 40 of theirs. The addition of carbon black significantly improves the strength and hardness of the sealant, greatly enhances the wear resistance of the sealant, and improves the processing performance of the sealant. PEG-4000 can form a protective film on the rubber surface, enhance the adhesion between the rubber and other materials, and improve the bonding strength and durability. Silicon carbide can increase the high-temperature resistance of the rubber, enabling the product to be used in a high-temperature environment. The selection of antioxidant 4020 and antioxidant RD used together takes into account both static thermal oxygen aging and mechanical fatigue, and can economically and efficiently expand the protection range. The present application also provides a preparation process for the above formula. By controlling this process and using a two-stage rubber mixing method, the advantages of each component in the formula are further exerted, and the temperature resistance, sealing performance, and strength of the EPDM rubber are improved. The EPDM rubber provided by the present application can be widely used in static seal products and can be used in the range below 180°C, solving the technical problem that when the temperature exceeds 165°C, it is necessary to use more expensive fluororubber, and has broad application prospects.

[0062] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0063] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the protection scope of the present application.

Claims

1. An EPDM rubber for high temperature operation at 180°C, characterized in that: The invention specifically comprises the following components by weight: 108 parts of EPDM rubber, 70-90 parts of carbon black, 3-5 parts of metal oxide, 0.5-1.5 parts of stearic acid, 1-3 parts of antioxidant, 2-4 parts of polyethylene glycol, 4-6 parts of silicon carbide, 2.25-5.15 parts of crosslinking agent, and 1-1.4 parts of auxiliary crosslinking agent; The EPDM rubber includes EPDM rubber particles and liquid EPDM rubber.

2. The EPDM rubber for high temperature operation at 180°C according to claim 1, characterized in that: The mass ratio of the EPDM rubber particles to the liquid EPDM rubber is 12.5:

1.

3. The EPDM rubber for high temperature operation at 180°C according to claim 1, characterized in that: The EPDM rubber particles include LANXESS 2650C, SINOPEC Mitsui 2060M, and SINOPEC Mitsui 3090EM; the liquid EPDM rubber is EB15.

4. The EPDM rubber for high temperature operation at 180°C according to claim 3, characterized in that: The mass ratio of the LANXESS 2650C, the SINOPEC Mitsui 2060M and the SINOPEC Mitsui 3090EM is 2:2:

1.

5. The EPDM rubber for high temperature operation at 180°C according to claim 1, characterized in that: The metal oxide includes zinc oxide and magnesium oxide; the mass ratio of the zinc oxide to the magnesium oxide is 1:1; the antioxidant includes antioxidant 4020 and antioxidant RD, and the mass ratio of the antioxidant 4020 to the antioxidant RD is 1:1; the polyethylene glycol is one of polyethylene glycol-4000, polyethylene glycol-8000 or polyethylene glycol-10000.

6. The EPDM rubber for high temperature operation at 180°C according to claim 1, characterized in that: The auxiliary cross-linking agent is one of TAIC, TMPTMA or TAC; the cross-linking agent includes bis-25 and BIPB, and the mass ratio of bis-25 to BIPB is 1.15:

1.

7. A process for preparing EPDM rubber operating at a high temperature of 180°C, for producing the EPDM rubber as claimed in any one of claims 1 to 6, characterized in that: The specific steps include: (I) Ingredients: weigh the raw and auxiliary materials to be used according to the formula table; (ii) One-stage rubber refining: EPDM rubber is mixed, small materials are added for mixing, and then carbon black is added for rubber refining, and the rubber sheet is poured out after hanging the sheet to obtain a first-stage rubber; (III) Two-stage rubber mixing: After the first stage of rubber is parked, part of it is put into an internal mixer and a cross-linking agent is added, and then the remaining first stage of rubber is put into the internal mixer for rubber mixing and rubber discharge to obtain the finished EPDM rubber.

8. The process for preparing EPDM rubber for high temperature operation at 180°C according to claim 7, characterized in that: The specific steps of step (ii) are as follows: the rubber is put into the internal mixer at a speed of 40 r / min and a top bolt pressure of 6 MPa. After mixing for 40 seconds, small materials are added, the speed is reduced to 30 r / min, and carbon black is added after mixing for 30 seconds. After the temperature reaches 130°C, the bolt is lifted for 15 seconds, and the rubber is mixed to 155°C for rubber discharge. After the rubber is discharged to the open mixer, the thickness of the rubber sheet is maintained at 8-10 mm, and the hanging sheet is poured for 3 minutes.

9. The process for preparing EPDM rubber for high temperature operation at 180°C according to claim 7, characterized in that: The specific steps of step (iii) two-stage rubber mixing are as follows: after the first stage of rubber is parked for 24 hours, the speed of the internal mixer is 25-30r / min, the upper plug is 6Mpa, 2 / 3 of the first stage of rubber is put into the internal mixer and a cross-linking agent is added, and then the remaining 1 / 3 of the first stage of rubber is put in, and the plug is lifted when the rubber is mixed to 75°C, 85°C, and 95°C, and the rubber is discharged at 105°C to obtain the finished EPDM rubber.

10. An application of EPDM rubber for high temperature operation at 180°C, wherein the finished EPDM rubber obtained by the preparation process described in any one of claims 7 to 9 is used in static sealing products at a temperature within 180°C.

Images