High-water-pressure-resistant water-swellable EPDM (Ethylene-Propylene-Diene Monomer) rubber composition, rubber compound as well as preparation method and application thereof

Abstract

The invention relates to the technical field of manufacturing of automobile wading sealing strips, and discloses a high-water-pressure-resistant EPDM (Ethylene-Propylene-Diene Monomer) rubber composition capable of expanding when meeting water, a rubber compound as well as a preparation method and application of the rubber compound. The EPDM rubber composition comprises the following components in parts by weight: 100 parts of EPDM raw rubber and 40-70 parts of furnace black, 20 parts of heavy calcium carbonate; 30 to 60 parts of hydrogenated paraffin oil; 20 to 40 parts of water absorption expansion resin Altermix HA 300; 8-10 parts of activated zinc oxide; 1-2 parts of stearic acid; 1 to 2 parts of PEG (Polyethylene Glycol)-4000; 3-5 parts of calcium oxide; 1 part of sulfur; 3 to 4 parts of an environment-friendly accelerant LLB-2; and 0.2 to 0.5 part of an anti-scorching agent E-80GE. A rubber compound prepared from the EPDM rubber composition swells when encountering water and is good in high water pressure resistance, and the automobile wading sealing strip prepared from the EPDM rubber composition can meet the water sealing performance requirement which cannot be met by a conventional sealing strip when encountering high water pressure during wading.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile water-resistant sealing strip manufacturing, and in particular to an EPDM rubber composition resistant to high water pressure and swelling in contact with water, a rubber compound, and a preparation method and application thereof. Background Art

[0002] In order to further improve the high water pressure resistance and sealing performance of water-resistant sealing strips, the development and application of EPDM material glue and its manufacturing process that can meet conventional sealing performance while being able to withstand high water pressure and expand when the car is wading through water has become a new technological innovation trend in the field of automotive sealing strips.

[0003] The sealing principle of traditional automotive sealing strips is as follows Figure 1 、 Figure 2 As shown, Figure 1 In the schematic diagram of a single-channel contact seal for a car's water-resistant sealing strip, figure a represents the state of the sealing strip before it is compressed, and figure b represents the state of the sealing strip after it is compressed. The single-channel sealing here uses a sealing strip in contact with the car's sheet metal, causing the sealing strip to deform under pressure, and using rubber elasticity to achieve a sealing effect. The advantage is that this type of EPDM-based sealing strip has excellent aging resistance and good permanent compression set. When the car is not wading in water, it can meet the daily dustproof, windproof, and waterproof sealing requirements in the absence of water pressure. However, the sealing performance of this type of single-channel sealing strip will show problems of elastic attenuation and deterioration of the sealing effect over time during daily use, making it unsuitable for sealing under high water pressure.

[0004] Figure 2 The above is a schematic diagram of the double-channel extrusion seal of the automobile wading seal. It uses two sealing strips to squeeze and contact each other, so that the sealing strips are compressed to produce double deformation, and the elasticity of rubber is used to achieve the sealing effect. The advantage is that the sealing performance of this type of sealing strip made of EPDM is better than Figure 1 This type of sealing strip, while meeting the dustproof, windproof and waterproof effects in daily use, can partially achieve the anti-leakage sealing effect required when the car is wading for a short time. However, as the water pressure increases and the wading time increases when the car is wading, the risk of leakage will increase, and it is difficult to meet the sealing requirements under high water pressure.

[0005] The traditional automobile sealing strips given above are difficult to meet the requirements of withstanding high water pressure in water, regardless of whether they adopt single-channel contact sealing or double-channel extrusion sealing. This is because the performance properties of the sealing strips themselves do not meet the requirements, not the problem of the working conditions. Therefore, it is particularly important to develop new high-water-pressure-resistant automobile water-resistant sealing strips. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that the existing automobile water-resistant sealing strips cannot meet the sealing requirements under high water pressure. In order to overcome the above defects of the existing technology, the present invention provides an EPDM rubber composition that is resistant to high water pressure and expands when exposed to water, a mixed rubber, and its preparation method and application.

[0007] A first object of the present invention is to provide an EPDM rubber composition that is resistant to high water pressure and expands when exposed to water. The EPDM rubber composition comprises, by weight, 100 parts of EPDM raw rubber, 40-70 parts of furnace carbon black, 20 parts of heavy calcium carbonate, 30-60 parts of hydrogenated paraffin oil, 20-40 parts of water-swelling resin Altermix HA300, 8-10 parts of active zinc oxide, 1-2 parts of stearic acid, 1-2 parts of PEG-4000, 3-5 parts of calcium oxide, 1 part of sulfur, 3-4 parts of an environmental accelerator LLB-2, and 0.2-0.5 parts of a scorch retarder E-80GE.

[0008] Compared with the existing technology, the present application has the following advantages: the material prepared after vulcanization of the composition expands when exposed to water and can withstand high water pressure, meeting the sealing performance requirements of resisting high water pressure and preventing water leakage below 0.8 meters of the waistline of the entire car body after entering water.

[0009] In one possible embodiment, the EPDM raw rubber is a mixture of 60% (w / w) 10660C EPDM rubber and 40% (w / w) K6470C EPDM rubber.

[0010] In the above solution, 10660C raw rubber has an ultra-high molecular weight, providing better compression permanent deformation for the sealing strip, and K6470C raw rubber can provide better processability.

[0011] In one possible embodiment, the furnace carbon black is carbon black N-550.

[0012] In the above solution, N-550 carbon black not only meets the reinforcement effect of the rubber compound, but also provides better processing performance, improves production efficiency and reduces energy consumption.

[0013] In a possible implementation, the water-swellable resin Altermix HA300 is a mixture of sodium polyacrylate and sodium polymethacrylate, each accounting for 50% by mass.

[0014] In the above solution, the use of this water-absorbing and swelling resin can enable the product to expand rapidly when exposed to water and have unique dynamic water sealing performance.

[0015] In one possible embodiment, the scorch retarder E-80GE is N-phenyl-N (trichloromethyl-sulfonyl)-phenylsulfonylanilide.

[0016] In the above solution, E-80GE is used to achieve higher processing safety during the preparation of the rubber compound.

[0017] The second object of the present invention is to provide a rubber compound that is resistant to high water pressure and expands when exposed to water, which is prepared using the above-mentioned EPDM rubber composition as a raw material.

[0018] A third object of the present invention is to provide a method for preparing a rubber compound that is resistant to high water pressure and expands in water, comprising the following steps: S1, weighing the materials of stage I and mixing them in the first internal mixer with an upper bolt, first heating the temperature to 100-110°C, mixing at a high speed of 35-45 rpm and a pressure of 10-15 MPa for 5 seconds, then reducing the speed to 35-40 rpm and mixing for 2-4 minutes, and discharging the materials when the temperature reaches 140-150°C; the materials of stage I are EPDM raw rubber, furnace carbon black, heavy calcium carbonate, hydrogenated paraffin oil, water-swellable resin Altermix HA300, activated zinc oxide, stearic acid, and PEG-4000, weighed according to the component contents of the above-mentioned EPDM rubber composition; S2, the rubber material discharged from step S1 is added to a second internal mixer without an upper bolt for mixing, firstly forced cooling mixing is performed, and pressureless mixing is performed at a low speed of 8-12 rpm. When the temperature drops to 95-100°C, the stage II material is added, and mixing is performed at a speed of 20-25 rpm for 60 seconds. When the temperature rises to 110-120°C, the material is discharged; the stage II material is sulfur, environmental accelerator LLB-2, scorch retarder E-80GE and calcium oxide weighed according to the component contents in the above-mentioned EPDM rubber composition; S3, sending the rubber material discharged from step S2 to the first open mill for calendaring and wrapping rollers for one cycle, and automatically discharging the rubber material after the rubber material is swung for 80-90 seconds; S4, the rubber material discharged from step S3 is fed into the second open mill, and the rubber sheet is produced after a cycle of calendering and wrapping. The rubber sheet is soaked, cooled and air-dried, and then collected.

[0019] In the above scheme, the emergence of the new rubber compound preparation method has provided another option in the production process of water-resistant sealing strips for ordinary automobiles and amphibious vehicles. The vulcanized rubber compound is resistant to high water pressure and has good water expansion performance. While ensuring the performance of the rubber compound product, it also meets the sealing performance requirements of resistance to high water pressure and water leakage.

[0020] In a possible implementation manner, the film output in step S4 has a width of 80-100 mm and a thickness of 8-10 mm.

[0021] In the above scheme, this scale is specified to enable the film to be suitable for various types of extruders and realize barrier-free automatic glue feeding.

[0022] A fourth object of the present invention is to provide the use of the above-mentioned EPDM rubber composition or the rubber compound prepared by the above-mentioned method in automobile water-resistant sealing strips.

[0023] In the above scheme, the automobile water-crossing sealing strip prepared with the above raw materials has good resistance to high water pressure and water leakage below 0.8 meters of the waistline of the entire car body after the car enters the water, reducing the risk of water leakage caused by the attenuation of the sealing strip's sealing performance as the car ages.

[0024] In a possible embodiment, the automobile water-resistant sealing strips include waterproof strips of the automobile chassis, door opening strips, head sealing strips, door sill strips, and trunk sealing strips.

[0025] The beneficial effects of the present invention are: (1) The present invention adopts ultra-high molecular weight EPDM raw rubber to enable the sealing strip to obtain low compression permanent deformation and excellent weather resistance, while increasing the additional sealing performance of the sealing strip, meeting the water sealing performance that conventional sealing strips cannot achieve when the car is wading through water and encountering high water pressure.

[0026] (2) The present invention combines the traditional advantages of automotive sealing strips while avoiding the traditional defects. While ensuring the conventional performance of the sealing product, it adopts the industry-innovative series rubber refining process to further improve the overall water tightness of the sealing product.

[0027] (3) The present invention adopts an industry-innovative serial one-step rubber refining process, an intelligent and automated rubber refining control system, and an intelligent central dust collection and environmental protection treatment system.

[0028] (4) Since the EPDM rubber compound resistant to high water pressure and swelling in contact with water prepared by the present invention is similar to the raw rubber used in the conventional EPDM material currently used in the mainstream automotive sealing strip industry, the two have good compatibility and can obtain additional or special high water pressure resistant water sealing performance by extruding a single section or co-extruding the sections. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of a single-channel contact seal for a traditional automobile water-resistant seal strip; Figure 1 In the figure, a is a schematic diagram showing the state of the sealing strip before being compressed, and b is a schematic diagram showing the state of the sealing strip after being compressed; Figure 2 This is a schematic diagram of the double-pass extrusion seal of a traditional automobile wading seal strip; Figure 3 This is an exploded diagram of the application range of the automobile wading sealing strip; Figure 4 This is a schematic diagram of the extrusion cross-section of a single body of the automobile water-resistant sealing strip of the present invention; Figure 5 This is a schematic cross-sectional view of the co-extrusion composite of the automotive water-resistant sealing strip of the present invention; Figure 6 The present invention is a flow chart of the preparation process of the tandem one-step rubber compound; Figure 7 This is a diagram of the monomer extrusion and vulcanization production process of the sealing strip of the present invention; Figure 8 This is a diagram of the co-extrusion vulcanization production process of the composite body of the sealing strip of the present invention. DETAILED DESCRIPTION

[0030] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only intended to illustrate the implementation methods and typical parameters of the present invention, and are not intended to limit the parameter ranges described in the present invention. Reasonable variations derived therefrom are still within the scope of protection of the claims of the present invention.

[0031] It should be noted that the endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0032] Unless otherwise defined, all terms, symbols and other scientific terms used herein are intended to have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. In some cases, terms with conventional meanings are defined herein for the purpose of clarification or ease of reference, and such definitions herein should not be construed as indicating significant differences from conventional understandings in the art. The technical methods described or cited herein are generally well understood by those skilled in the art and are adopted by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents and instruments was carried out in accordance with the protocols and parameters given by the manufacturers.

[0033] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] The present embodiment relates to an EPDM rubber composition that is resistant to high water pressure and expands in contact with water. The EPDM rubber composition comprises, by weight: 100 parts of EPDM raw rubber, 40-70 parts of furnace carbon black; 20 parts of heavy calcium carbonate; 30-60 parts of hydrogenated paraffin oil; 20-40 parts of water-swellable resin Altermix HA300; 8-10 parts of activated zinc oxide; 1-2 parts of stearic acid; 1-2 parts of PEG-4000; 3-5 parts of calcium oxide; 1 part of sulfur; 3-4 parts of environmental accelerator LLB-2; and 0.2-0.5 parts of scorch retarder E-80GE.

[0035] See also Figure 6 The composite is used to prepare a rubber mix by adopting a series one-step rubber mixing process, and the specific steps are as follows: S1, weighing the materials of Section I and mixing them in the first internal mixer with an upper push bolt, first heating the temperature to 100-110°C, mixing at a high speed of 35-45 rpm and a pressure of 10-15 MPa for 5 seconds, then reducing the speed to 35-40 rpm and mixing for 2-4 minutes, and discharging the materials when the temperature reaches 140-150°C; the materials of Section I are EPDM raw rubber, furnace carbon black, heavy calcium carbonate, hydrogenated paraffin oil, water-swellable resin Altermix HA300, activated zinc oxide, stearic acid, and PEG-4000, weighed according to the component contents of the above-mentioned EPDM rubber composition; S2, the rubber material discharged from step S1 is added to a second lower internal mixer without an upper ejector bolt for mixing, firstly forced cooling mixing is performed, and pressureless mixing is performed at a low speed of 8-12 rpm. When the temperature drops to 95-100° C., the stage II material is added and mixed at a speed of 20-25 rpm for 60 seconds. The material is discharged when the temperature rises to 110-120° C.; the stage II material is sulfur, environmental accelerator LLB-2, scorch retarder E-80GE and calcium oxide weighed according to the component contents in the above-mentioned EPDM rubber composition; S3, using the rubber material automatic conveying system 1 to feed the rubber material discharged in step S2 into the automatic rubber tamping mill for calendering and wrapping the rollers for one cycle, and automatically discharge the rubber after the rubber material is swung for 80-90 seconds; S4, using the rubber material automatic conveying system 2 to send the rubber material discharged in step S3 to the automatic sheet discharging mill, after a cycle of calendering and wrapping, the rubber sheet is discharged. The rubber sheet is soaked in the automatic rubber filter, cooled and air-dried in the automatic rubber cooler, and then enters the automatic material receiving machine to receive the material and send it to the intelligent three-dimensional warehouse for storage.

[0036] The entire process uses automatic batching and automatic feeding, and also adopts central dust collection and intelligent waste gas treatment system to treat dust and waste gas.

[0037] The EPDM raw rubber is a mixture of 60% (w / w) 10660C EPDM rubber and 40% (w / w) K6470C EPDM rubber. The furnace carbon black is carbon black N-550. The water-swellable resin Altermix HA300 is a mixture of 50% sodium polyacrylate and 50% sodium polymethacrylate. The scorch retarder E-80GE is N-phenyl-N(trichloromethyl-sulfonyl)-phenylsulfonylanilide. The film produced in step S4 has a width of 80-100 mm and a thickness of 8-10 mm.

[0038] The obtained rubber mixture is resistant to high water pressure, expands when exposed to water, and is widely used in automobile water-resistant sealing strips.

[0039] Figure 7 The process of producing automobile water-proof sealing strips by monomer extrusion and vulcanization using the above-mentioned rubber compound is given, including the steps of monomer extrusion → high temperature vulcanization → plasma treatment → surface spraying → high temperature curing → cooling and pulling → cutting and collecting. This monomer extrusion process is similar to the process of preparing sealing strips by rubber monomer extrusion in the prior art, with only slight differences in parameters of certain links. It is not the core of the present invention, so it will not be elaborated in this embodiment. The cross-sectional schematic diagram of the monomer extruded automobile water-proof sealing strip obtained from one of the monomer extrusion experiments is shown in FIG. Figure 4 As shown in the figure, it can be seen that the extruded cross-section of the automobile water-resistant sealing strip monomer of this embodiment is dense and uniform, which provides a basis for the automobile water-resistant sealing strip to expand when exposed to water and withstand high water pressure.

[0040] Figure 8 A process route for producing automobile water-crossing sealing strips by co-extrusion and vulcanization of a composite using the above-mentioned rubber compound is given. This compound is to extrude the high water pressure resistant water-swellable rubber compound prepared in this application and the ordinary EPDM rubber compound in the prior art on a preformed metal skeleton. The process includes the following steps: metal skeleton → preforming → composite extrusion of the high water pressure resistant water-swellable rubber compound and the ordinary EPDM rubber compound → high temperature vulcanization → plasma treatment → surface spraying → high temperature curing → cooling and pulling → cutting and collecting. This composite extrusion process is similar to the process of preparing sealing strips by extruding rubber compounds in the prior art, except for some slight differences in parameters of certain links. It is not the core of the present invention, so it will not be elaborated in this embodiment. The cross-sectional schematic diagram of the composite extruded automobile water-crossing sealing strip obtained from one of the composite extrusion experiments is shown in the figure. Figure 5 As shown in the figure, it can be seen that the extruded cross-section of the automobile water-resistant sealing strip composite of this embodiment is dense and uniform (the shaded part in the figure is the high water pressure resistant water-swellable rubber compound in this embodiment, and the non-shaded part is the EPDM rubber compound in the prior art).

[0041] Figure 3 An exploded diagram of the application range of automobile water-resistant sealing strips is given. The automobile sealing strips prepared in this embodiment can be used in the fields of automobile chassis waterproof strips, door opening strips, head sealing strips, door sill strips, trunk sealing strips, etc.

[0042] A specific preparation example of a high water pressure resistant water-swelling rubber compound of this embodiment is given below to better illustrate the concept of the present invention. Example 1

[0043] A high water pressure resistant water swelling rubber compound is prepared by the following method: S1, the materials of Section I are sequentially fed into the fully enclosed first internal mixer through the fully enclosed raw material automatic conveying system, the fully enclosed automatic weighing and feeding system according to the set software setting program for mixing: the first step is to perform high-speed and high-pressure mixing according to the set program, wherein the rotor speed of the internal mixer is 40r / min, the upper push pin pressure is 13MPa, and when the temperature of the mixed rubber reaches 100-105℃, the push pin is raised, stayed for 5 seconds, and the rotor speed is reduced to 27r / min; the second step is to lower the push pin, increase the rotor speed to 40r / min, and the mixing time is about 3 minutes. When the temperature of the mixed rubber reaches 145℃, the system automatically discharges the materials. The entire mixing process of the first stage is intelligent and fully automatic, and no manual control is required.

[0044] S2, the rubber material discharged from step S1 is automatically fed into the next internal mixer without an upper bolt, and enters the open mixer for forced cooling and mixing. The first step is to perform low-speed, pressureless mixing according to the set program, wherein the rotor speed of the internal mixer is 10r / min. When the temperature of the mixed rubber drops to 98°C, the material of stage II is automatically fed, and the rotor speed of the internal mixer is automatically increased to 23r / min; when the temperature of the mixed rubber rises to 115°C, the system automatically discharges the material. The entire small-material feeding and mixing process is intelligent and fully automatic, and no manual control is required.

[0045] S3, the rubber material discharged from step S2 enters the automatic tamping system of the first open mill, is rolled on the roller for one cycle, and is automatically sheeted after 85 seconds of swaying. The entire rubber material tamping process is intelligent and fully automatic, without manual control.

[0046] S4, the rubber material discharged from step S3 enters the automatic sheet discharging system of the second open mixing mill. After one cycle of calendering and wrapping, the rubber material passes through the automatic sheet discharging device and is transported into the cooling isolation tank. After the rubber sheet is soaked in the isolation liquid, it is automatically hung on the rubber sheet cooler. After air drying and cooling, it enters the intelligent automatic material receiving system. After automatic weighing, the rubber material is transferred to the inspection area by the intelligent AGV car. After passing the inspection, it enters the extrusion process.

[0047] Among them, the automatic sheet output width of the second open mill in step S4 is 90 mm and the thickness is 9 mm.

[0048] The materials for stage I consist of EPDM rubber (a blend of ARLANXEO 10660C and K6470C rubber), carbon black N-550, heavy calcium carbonate, hydrogenated paraffin oil, water-swellable resin, activated zinc oxide, stearic acid, and polyethylene glycol. The materials for stage II consist of sulfur, a vulcanizing agent, an environmental accelerator, a scorch retarder, and calcium oxide. The raw material formula, by weight, includes: 60 parts 10660C rubber, 40 parts K6470C rubber, 40 parts carbon black N-550, 20 parts heavy calcium carbonate, 45 parts paraffin oil, 20 parts Altermix HA300 water-swellable resin, 8 parts activated zinc oxide, 1 part stearic acid, 2 parts PEG-4000, 4 parts calcium oxide, 1 part sulfur, 3.5 parts LLB-2, an environmental accelerator, and 0.4 parts E-80, an anti-scorch agent. All raw materials are commercially available, with their sources listed in Table 1.

[0049] Table 1 Sources of raw materials for the EPDM rubber composition of this example Example 2

[0050] The difference between this embodiment and embodiment 1 is that the amount of water-swellable resin Altermix HA300 added is 30 parts. Example 3

[0051] The difference between this embodiment and embodiment 1 is that the amount of water-swellable resin Altermix HA300 added is 40 parts.

[0052] The rubber mixtures obtained in Examples 1-3 were subjected to water swelling test, compression set test after water swelling test and underwater water leakage test. The relevant data and performance test results are shown in Table 2 below.

[0053] Table 2 Experimental parameters and performance test results of Examples 1-3

[0054] As can be seen from Table 2, the rubber mix prepared by the tandem one-step rubber mixing process of the present invention has a large water absorption expansion rate, a small permanent compression deformation after water absorption expansion, and good water leakage prevention performance, and can be widely used in the manufacture of automotive water-resistant sealing strips.

[0055] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. An EPDM rubber composition resistant to high water pressure and swelling in contact with water, characterized in that: The EPDM rubber composition comprises, by weight, 100 parts of EPDM raw rubber, 40-70 parts of furnace carbon black, 20 parts of heavy calcium carbonate, 30-60 parts of hydrogenated paraffin oil, 20-40 parts of water-swellable resin Altermix HA300, 8-10 parts of active zinc oxide, 1-2 parts of stearic acid, 1-2 parts of PEG-4000, 3-5 parts of calcium oxide, 1 part of sulfur, 3-4 parts of environmental accelerator LLB-2, and 0.2-0.5 parts of scorch retarder E-80GE.

2. The high water pressure resistant and water-swellable EPDM rubber composition according to claim 1, characterized in that: The EPDM raw rubber is a mixture of 60% (w / w) 10660C EPDM rubber and 40% (w / w) K6470C EPDM rubber.

3. The high water pressure resistant and water-swellable EPDM rubber composition according to claim 1, characterized in that: The furnace carbon black is carbon black N-550.

4. The high water pressure resistant and water-swellable EPDM rubber composition according to claim 1, characterized in that: The water-swellable resin Altermix HA300 is a mixture of sodium polyacrylate and sodium polymethacrylate, each accounting for 50% (w / w).

5. The high water pressure resistant and water-swellable EPDM rubber composition according to claim 1, characterized in that: The scorch retarder E-80GE is N-phenyl-N (trichloromethyl-sulfonyl)-phenylsulfonylanilide.

6. A rubber compound resistant to high water pressure and swelling in contact with water, characterized in that: The invention is prepared from the EPDM rubber composition according to any one of claims 1 to 5.

7. The method for preparing a high water pressure resistant water swelling rubber compound according to claim 6, characterized in that: The steps include: S1, weighing the materials of stage I and mixing them in a first internal mixer with an upper bolt, first heating the temperature to 100-110°C, mixing at a high speed of 35-45 rpm and a pressure of 10-15 MPa for 5 seconds, then reducing the speed to 35-40 rpm and mixing for 2-4 minutes, and discharging the materials when the temperature rises to 140-150°C; the materials of stage I are EPDM raw rubber, furnace carbon black, heavy calcium carbonate, hydrogenated paraffin oil, water-swellable resin Altermix HA300, activated zinc oxide, stearic acid, and PEG-4000 weighed according to the component contents of the EPDM rubber composition according to any one of claims 1-5; S2. The rubber material discharged from step S1 is added to a second internal mixer without an upper bolt for mixing. First, forced cooling and mixing are performed, and pressureless mixing is performed at a low speed of 8-12 rpm. When the temperature drops to 95-100° C., the stage II material is added and mixed at a speed of 20-25 rpm for 60 seconds. The material is discharged when the temperature rises to 110-120° C.; the stage II material is sulfur, environmental accelerator LLB-2, scorch retarder E-80GE, and calcium oxide weighed according to the component contents in the EPDM rubber composition according to any one of claims 1 to 5; S3, sending the rubber material discharged from step S2 to the first open mill for calendaring and wrapping rollers for one cycle, and automatically discharging the rubber material after the rubber material is swung for 80-90 seconds; S4, feeding the rubber material discharged from step S3 into the second open mill, calendering the rolls for one cycle and producing a rubber sheet, which is soaked, cooled and air-dried before being collected to obtain a mixed rubber that is resistant to high water pressure and expands when exposed to water.

8. The method for preparing a high water pressure resistant water swelling rubber compound according to claim 7, characterized in that: The film output in step S4 has a width of 80-100 mm and a thickness of 8-10 mm.

9. Use of the EPDM rubber composition according to any one of claims 1 to 5 or the rubber compound according to claim 6 in automobile water-resistant sealing strips.

10. The use according to claim 9, characterized in that The automobile water-crossing sealing strips include waterproof strips of the automobile chassis, door opening strips, head sealing strips, door sill strips, and luggage compartment sealing strips.

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