Preparation method of rubber for air spring envelope

Abstract

The present invention discloses a method for preparing rubber for air spring bladder, which is characterized by comprising the following steps: using an internal mixer to masterbatch to obtain a masterbatch rubber sheet, after standing at room temperature for 8 hours, using an internal mixer to final-batch to obtain a final-batch rubber sheet, standing at room temperature for 4 hours after the sheet is produced, calendering, and matching with calendered cord fabric to form a capsule, and finally putting the capsule into a vulcanization mold, and vulcanizing to obtain the required rubber. The advantage is that the above method can prepare a rubber material with good air tightness, good weather resistance, excellent fatigue resistance and low temperature resistance, which can be used to prepare the bladder of the air spring on new energy vehicles, so as to solve the problem of premature fatigue failure of the rubber currently used to prepare the bladder of the air spring on new energy vehicles, resulting in a shortened life of the air spring.

Description

Technical Field

[0001] The invention relates to a method for preparing rubber, in particular to a method for preparing rubber for air spring bag skin. Background Art

[0002] With the guidance of green environmental protection policies of the automobile industry in various countries around the world, major automobile manufacturers at home and abroad are developing new energy vehicles, mainly electric vehicles, more and more rapidly. Since new energy vehicles do not have fuel engines and the cockpit is quieter, the noise, vibration and harshness (NVH) of new energy vehicles has become the most important evaluation indicator for vehicle research and development.

[0003] As an important shock-absorbing component of new energy vehicles, air spring suspension is used to significantly improve driving comfort. The air spring bladder is an indispensable component of automobile air spring suspension. It is fastened to the upper and lower end cover connectors of the air spring to form a closed chamber. The air spring's shock-absorbing effect is achieved by filling and deflating the closed chamber. The bladder is a rubber elastomer with a cord fabric structure. It is a consumable and vulnerable part. The performance of the bladder directly determines the performance of the entire air spring. Therefore, when designing, in addition to paying attention to its appearance and size, it is also necessary to pay attention to its air tightness, low temperature resistance, explosion resistance, fatigue characteristics and other properties. At present, the rubber used to manufacture the bladder of air springs on the market mainly uses natural rubber as the main raw material. Natural rubber is a non-polar rubber with a high degree of unsaturation. It is very easy to age during long-term outdoor use. Therefore, the rubber used to make the bladder of air springs with natural rubber as the main raw material has begun to be difficult to meet the use requirements in terms of air tightness, weather resistance, and durable fatigue resistance. There is a problem of early fatigue failure of the bladder, which shortens the life of the air spring. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing rubber for air spring bladders. Through the preparation method, a rubber material with good air tightness, good weather resistance, excellent fatigue resistance and low temperature resistance can be obtained. The rubber material can be used to manufacture the bladders of air springs on new energy vehicles to increase the service life of the air springs.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A method for preparing rubber for air spring bladder skin comprises the following steps:

[0007] (1)Masterbatch mixing in an internal mixer: First, 60 - 80 parts by mass of chloroprene rubber, 33 - 17 parts by mass of epoxidized natural rubber, and 7 - 3 parts by mass of styrene - butadiene rubber are put into the internal mixer together. Lower the upper plug of the internal mixer for mixing. After mixing for 60 seconds, raise the upper plug, and add 3 - 5 parts by mass of magnesium oxide, 0.5 - 1.5 parts by mass of stearic acid, 3 - 5 parts by mass of homogeneous agent, 4 - 6 parts by mass of antioxidant, 1 - 2 parts by mass of protective wax, 1 - 3 parts by mass of polyethylene wax, 1 - 2 parts by mass of processing aid, and 35 - 55 parts by mass of reinforcing filler. Lower the upper plug and continue mixing. After mixing for 15 seconds, raise the upper plug, add 6 - 10 parts by mass of plasticizer, lower the upper plug and continue mixing. When the mixing temperature reaches 115°C, raise the upper plug for 15 seconds, then lower the upper plug and mix until the temperature reaches 125°C for discharging the rubber, obtaining the masterbatch sheet;

[0008] (2)Let the above - mentioned masterbatch sheet stand at room temperature for 8 hours;

[0009] (3)Final mixing in an internal mixer: Put the masterbatch sheet that has stood at room temperature for 8 hours into the internal mixer together with 4 - 6 parts by mass of zinc oxide, 0.5 - 1.5 parts by mass of antioxidant, 4 - 6 parts by mass of adhesive, 0.4 - 0.8 parts by mass of vulcanizing agent, 2.5 - 3.5 parts by mass of accelerator, and 0.2 - 0.4 parts by mass of scorch retarder. Lower the upper plug for mixing. When the mixing temperature reaches 90°C, raise the upper plug for 30 seconds, then lower the upper plug and mix until the temperature reaches 100°C for discharging the rubber, obtaining the final - mix sheet;

[0010] (4)Sheet out the final - mix sheet obtained above on a two - roll open mill and let it stand at room temperature for 4 hours;

[0011] (5)Roll the final - mix sheet that has stood at room temperature for 4 hours through a calender into a sheet with a set thickness, and match it with calendered cord fabric of a suitable thickness to form a capsule;

[0012] (6)Put the capsule obtained in the above steps into a mold, and at a vulcanization temperature of 150 - 170°C, close the mold and vulcanize for 10 - 15 minutes to obtain the required rubber.

[0013] The chloroprene rubber used in step (1) is DCR 40A chloroprene rubber, produced by Denki Kagaku Kogyo Kabushiki Kaisha of Japan. This grade of chloroprene rubber is sulfur - regulated, with excellent physical and mechanical properties, adhesiveness, and good dynamic flex resistance.

[0014] The epoxidized natural rubber used in step (1) is ENR 25 epoxidized natural rubber, produced by Mitsui Chemicals, Inc. of Japan. This epoxidized natural rubber has better airtightness, good compatibility with chloroprene rubber, high bonding strength, and good low - temperature resistance.

[0015] The styrene-butadiene rubber used in step (1) is SBR 1502 synthetic rubber, produced by Qilu Branch of China Petroleum & Chemical Corporation. This synthetic rubber has good heat and abrasion resistance, and a small amount of addition can improve the operability of the calendering process of the rubber compound.

[0016] The magnesium oxide used in step (1) is high-activity magnesium oxide RS-180, produced by Yuncheng Yunsheng Chemical Co., Ltd., Shanxi. It participates in the double-bond reaction in chloroprene rubber to form a cross-linked structure, causing cross-linking between rubber molecules, thereby increasing the hardness and strength of the rubber. At the same time, it can also improve the scorch resistance of the rubber compound.

[0017] The stearic acid used in step (1) is SA1850 stearic acid, produced by Hangzhou Zanyu Oil Technology Co., Ltd. Its reaction with metal oxides can enhance the activity of accelerators and is the main vulcanization accelerating auxiliary agent.

[0018] The homogenizer used in step (1) is 40MSF uniform tackifier, produced by STRUKTOL COMPANY, Germany. Through this homogenizer, the uniformity of mixing between elastic polymers with different polarities and viscosities can be significantly improved, achieving an enhancement in the uniformity of mixing.

[0019] The anti-aging agents used in step (1) are a combination of OCTAMINE anti-aging agent and DTPD anti-aging agent. Among them, the OCTAMINE anti-aging agent is produced by SI Group, and the DTPD anti-aging agent is produced by Yichang Xingchun Chemical Co., Ltd. The OCTAMINE anti-aging agent is an excellent anti-aging agent that can effectively improve the high-temperature resistance, outdoor oxidation resistance, and flex fatigue aging resistance of chloroprene rubber; the DTPD anti-aging agent can react with free radicals in the rubber molecular chain to prevent oxidation reactions caused by free radicals. The combined application of the two has a synergistic effect, ensuring the long-term effectiveness of the heat resistance and weather resistance of the prepared rubber and extending the flex fatigue life.

[0020] The protective wax used in step (1) is Antilux 654 microcrystalline wax, produced by Rhein Chemie (Qingdao) Co., Ltd. It can effectively prevent the surface of the rubber from cracking due to the influence of ozone and weather.

[0021] The polyethylene wax used in step (1) is BN-200 polyethylene wax, produced by BOUNI CHEMICAL CO., LTD. It can prevent sticking to the roller and improve the operability of the calendering process of the rubber compound.

[0022] The processing aid used in step (1) is Haftolat / P processing aid, produced by KETTLITZ COMPANY, Germany. It can significantly reduce the mixing temperature of the rubber compound and avoid the scorching tendency of sensitive rubber compounds, especially neoprene rubber.

[0023] The reinforcing filler used in step (1) is a combination of VN3 silica and N550 carbon black. VN3 silica is produced by Evonik Industries AG, Germany, and N550 carbon black is produced by Cabot (Tianjin) Chemical Co., Ltd. VN3 silica can provide the rubber with high tensile strength, tear strength and abrasion resistance; N550 carbon black has good processability, medium reinforcing property, good elasticity and resilience. The combination of the two can make the tear resistance and fatigue resistance of the rubber more excellent.

[0024] The plasticizer used in step (1) is Mediaplast PM plasticizer, produced by KETTLITZ COMPANY, Germany. It has excellent compatibility with neoprene rubber, and can make the vulcanized neoprene rubber products obtain excellent low-temperature flexibility.

[0025] The zinc oxide used in step (3) is indirect method zinc oxide with a high content of more than 99.7%, produced by Anhui Hanshan County Jinhua Zinc Oxide Factory.

[0026] The anti-aging agent used in step (3) is anti-aging agent ZMTI, produced by R.T. Vanderbilt Company, Inc. The anti-aging agent has obvious anti-thermal aging effect, and has a synergistic effect when used in combination with amine anti-aging agents, and is used to improve the heat and oxygen aging resistance.

[0027] The adhesive used in step (3) is a combination of SCCTACK TR-1102 tackifying resin and SCCTACK ST-6000 phenolic tackifying resin, produced by SCC RUBBER CHEMICAL. SCCTACK TR-1102 tackifying resin is used to promote the uniform mixing between rubbers with different viscosities or polarities, and helps the uniform dispersion of fillers in the rubber; SCCTACK ST-6000 phenolic tackifying resin gives the mixed rubber compound high viscosity, which is beneficial to the forming and fitting of the rubber compound and reduces the residual air between the rubber layers.

[0028] The vulcanizing agent used in step (3) is insoluble sulfur IS60-75, produced by Ningbo Aikemu New Materials Co., Ltd. Using this vulcanizing agent can effectively avoid the problem of blooming of the rubber layer.

[0029] The accelerator used in the step (3) is a combination of N-cyclohexyl-2-benzothiazole sulfenamide and diethyl diphenyl thiuram disulfide, which is produced by Ningbo ACM New Materials Co., Ltd. N-cyclohexyl-2-benzothiazole sulfenamide is a post-effect high-speed vulcanization accelerator, and diethyl diphenyl thiuram disulfide is an ultra-accelerator with a longer scorch time. When used in combination, they can ensure sufficient rubber cross-linking reaction and endow the vulcanized rubber with high mechanical strength, low compression set, and good dynamic fatigue performance.

[0030] The scorch retarder used in the step (3) is CTP scorch retarder, which is produced by Shandong Yanggu Huatai Chemical Co., Ltd. Using this kind of scorch retarder can improve the storage stability of the rubber compound.

[0031] Compared with the prior art, the advantages of the present invention are as follows: This method uses a blend of chloroprene rubber, epoxidized natural rubber, and styrene-butadiene rubber in proportion as the matrix. Among them, chloroprene rubber has excellent physical and mechanical properties, good viscosity, and excellent dynamic flex resistance; epoxidized natural rubber has good airtightness, good compatibility with chloroprene rubber, large bonding strength, and good low-temperature resistance; styrene-butadiene rubber has good heat and abrasion resistance, and a small amount of addition can improve the operability of the calendering process of the rubber compound. The three are blended and proportionally combined with a homogenizer, highly active magnesium oxide, polyethylene wax, processing aids, plasticizers, adhesives, stearic acid, protective wax, anti-aging agents, reinforcing fillers, zinc oxide, accelerators, vulcanizing agents, and rubber scorch retarders, and a rubber material with good airtightness, good weather resistance, excellent fatigue resistance, and good low-temperature resistance can be prepared. This kind of rubber material can be used to prepare the bladder of the air spring on new energy vehicles to solve the problem of the shortened life of the air spring caused by the early fatigue failure of the rubber for preparing the bladder of the air spring on new energy vehicles. Specific embodiments

[0032] The present invention will be further described in detail below with reference to the embodiments.

[0033] Embodiment 1: A method for preparing rubber for an air spring bladder, comprising the following steps:

[0034] (1)Masterbatch mixing in a Banbury mixer: First, 60 parts by mass of DCR 40A chloroprene rubber, 33 parts by mass of ENR 25 epoxidized natural rubber, and 7 parts by mass of SBR1502 styrene-butadiene rubber are put into the Banbury mixer together, and the upper plug of the Banbury mixer is lowered for mixing; after mixing for 60 seconds, the upper plug is raised, and 3 parts by mass of highly active magnesium oxide, 0.5 part by mass of stearic acid, 3 parts by mass of 40MSF homogeneous agent, 1.5 parts by mass of OCTAMINE antioxidant, 2.5 parts by mass of DTPD antioxidant, 1 part by mass of 654 microcrystalline wax, 1 part by mass of BN-200 polyethylene wax, 1 part by mass of Haftolat / P processing aid, 5 parts by mass of VN3 silica, and 30 parts by mass of N550 carbon black are added. Then the upper plug is lowered to continue mixing; after mixing for 15 seconds, the upper plug is raised, and 6 parts by mass of Mediaplast PM plasticizer is added. The upper plug is lowered to continue mixing; when the mixing temperature reaches 115 °C, the upper plug is raised for 15 seconds, and then the upper plug is lowered to mix until the discharge temperature reaches 125 °C to obtain a masterbatch sheet;

[0035] (2)The above masterbatch sheet is parked at room temperature for 8 hours;

[0036] (3)Final mixing in a Banbury mixer: The masterbatch sheet parked at room temperature for 8 hours above is put into the Banbury mixer together with 4 parts by mass of zinc oxide, 0.5 part by mass of ZMTI antioxidant, 2 parts by mass of SCCTACK TR-1102 tackifying resin and 2 parts by mass of SCCTACK ST-6000 phenolic tackifying resin, 0.4 part by mass of insoluble sulfur IS60-75, 1.5 parts by mass of N-cyclohexyl-2-benzothiazole sulfenamide accelerator, 1 part by mass of diethyl diphenyl thiuram disulfide accelerator, and 0.2 part by mass of CTP scorch retarder. The upper plug is lowered for mixing. When the mixing temperature reaches 90 °C, the upper plug is raised for 30 seconds, and then the upper plug is lowered to mix until the discharge temperature reaches 100 °C to obtain a final mixing sheet;

[0037] (4)The final mixing sheet obtained above is sheeted on a two-roll mill and parked at room temperature for 4 hours;

[0038] (5)The final mixing sheet parked at room temperature for 4 hours above is calendered into a sheet with a thickness of 0.6 mm by a calender, and is paired with a calendered cord fabric with a model of PA66 840D / 1 and a thickness of 0.7 mm to form a capsule;

[0039] (6)The capsule obtained in the above steps is put into a mold and vulcanized for 15 minutes at a vulcanization temperature of 150 °C to obtain the required rubber.

[0040] Example 2: A method for preparing rubber for an air spring bladder, comprising the following steps:

[0041] (1)Masterbatch mixing in an internal mixer: First, 70 parts by mass of DCR 40A chloroprene rubber, 25 parts by mass of ENR 25 epoxidized natural rubber, and 5 parts by mass of SBR1502 styrene-butadiene rubber are put into the internal mixer together, and the upper plug of the internal mixer is lowered for mixing; after mixing for 60 seconds, the upper plug is raised, and 4 parts by mass of highly active magnesium oxide, 1 part by mass of stearic acid, 4 parts by mass of 40MSF homogeneous agent, 2 parts by mass of OCTAMINE antioxidant, 3 parts by mass of DTPD antioxidant, 1.5 parts by mass of 654 microcrystalline wax, 2 parts by mass of BN-200 polyethylene wax, 1.5 parts by mass of Haftolat / P processing aid, 10 parts by mass of VN3 precipitated silica, and 35 parts by mass of N550 carbon black are added. Then the upper plug is lowered to continue mixing; after mixing for 15 seconds, the upper plug is raised, and 8 parts by mass of Mediaplast PM plasticizer is added, and the upper plug is lowered to continue mixing; when the mixing temperature reaches 115 °C, the upper plug is raised for 15 seconds, and then the upper plug is lowered to mix until the discharge temperature reaches 125 °C to obtain the masterbatch sheet;

[0042] (2)Let the above masterbatch sheet stand at room temperature for 8 hours;

[0043] (3)Final mixing in an internal mixer: The masterbatch sheet that has stood at room temperature for 8 hours is put into the internal mixer together with 5 parts by mass of zinc oxide, 1 part by mass of ZMTI antioxidant, 2.5 parts by mass of SCCTACK TR-1102 tackifying resin, 2.5 parts by mass of SCCTACK ST-6000 phenolic tackifying resin, 0.6 part by mass of insoluble sulfur IS60-75, 1.8 parts by mass of N-cyclohexyl-2-benzothiazole sulfenamide accelerator, 1.2 parts by mass of diethyl diphenyl thiuram disulfide accelerator, and 0.3 part by mass of CTP scorch retarder. The upper plug is lowered for mixing. When the mixing temperature reaches 90 °C, the upper plug is raised for 30 seconds, and then the upper plug is lowered to mix until the discharge temperature reaches 100 °C to obtain the final mixing sheet;

[0044] (4)Sheet out the final mixing sheet obtained above on a two-roll mill and let it stand at room temperature for 4 hours;

[0045] (5)Calender the final mixing sheet that has stood at room temperature for 4 hours into a sheet with a thickness of 0.6 mm, and match it with calendered cord fabric of model PA66 840D / 1 and a thickness of 0.7 mm to form a capsule;

[0046] (6)Put the capsule obtained in the above steps into a mold, and vulcanize it for 12.5 minutes under a vulcanization temperature of 160 °C to obtain the required rubber.

[0047] Example 3: A method for preparing rubber for an air spring bladder skin, comprising the following steps:

[0048] (1)Masterbatch mixing in an internal mixer: First, 80 parts by mass of DCR 40A chloroprene rubber, 17 parts by mass of ENR 25 epoxidized natural rubber, and 3 parts by mass of SBR1502 styrene-butadiene rubber are put into the internal mixer together, and the upper ram of the internal mixer is lowered for mixing; after mixing for 60 seconds, the upper ram is raised, and 5 parts by mass of high-activity magnesium oxide, 1.5 parts by mass of stearic acid, 5 parts by mass of 40MSF homogeneous agent, 2.5 parts by mass of OCTAMINE antioxidant, 3.5 parts by mass of DTPD antioxidant, 2 parts by mass of 654 microcrystalline wax, 3 parts by mass of BN-200 polyethylene wax, 2 parts by mass of Haftolat / P processing aid, 15 parts by mass of VN3 silica, and 40 parts by mass of N550 carbon black are added, and the upper ram is lowered to continue mixing; after mixing for 15 seconds, the upper ram is raised, 10 parts by mass of Mediaplast PM plasticizer is added, and the upper ram is lowered to continue mixing; when the mixing temperature reaches 115°C, the upper ram is raised for 15 seconds, and then the upper ram is lowered and mixed until the discharge temperature reaches 125°C to obtain the masterbatch sheet;

[0049] (2)Let the above masterbatch sheet stand at room temperature for 8 hours;

[0050] (3)Final mixing in an internal mixer: The masterbatch sheet that has stood at room temperature for 8 hours above is put into the internal mixer together with 6 parts by mass of zinc oxide, 1.5 parts by mass of ZMTI antioxidant, 3 parts by mass of SCCTACK TR-1102 tackifying resin, 3 parts by mass of SCCTACK ST-6000 phenolic tackifying resin, 0.8 parts by mass of insoluble sulfur IS60-75, 2 parts by mass of N-cyclohexyl-2-benzothiazole sulfenamide accelerator, 1.5 parts by mass of diethyl diphenyl thiuram disulfide accelerator, and 0.4 parts by mass of CTP scorch retarder, and the upper ram is lowered for mixing. When the mixing temperature reaches 90°C, the upper ram is raised for 30 seconds, and then the upper ram is lowered and mixed until the discharge temperature reaches 100°C to obtain the final mixing sheet;

[0051] (4)Sheet out the final mixing sheet obtained above on a two-roll open mill and let it stand at room temperature for 4 hours;

[0052] (5)Calender the final mixing sheet that has stood at room temperature for 4 hours above into a sheet with a thickness of 0.6 mm, and match it with calendered cord fabric of model PA66 840D / 1 and a thickness of 0.7 mm to form a capsule;

[0053] (6)Put the capsule obtained in the above steps into a mold and vulcanize it by closing the mold at a vulcanization temperature of 170°C for 10 minutes to obtain the required rubber.

[0054] The properties of the rubber conventionally used for manufacturing the air spring envelope and the three kinds of rubbers for manufacturing the air spring envelope prepared by the above three embodiments were respectively compared and analyzed through tensile tests, airtightness, low-temperature brittleness temperature, bursting pressure, and bench fatigue tests; a universal tensile testing machine was used to test the tensile strength and elongation at break of the rubber conventionally used for manufacturing the air spring envelope and the three kinds of rubbers for manufacturing the air spring envelope prepared by the above three embodiments; a helium leak detection test bench was used to test the airtightness of the rubber conventionally used for manufacturing the air spring envelope and the assembled parts of the three kinds of rubbers for manufacturing the air spring envelope prepared by the above three embodiments; a low-temperature brittleness tester was used to test the low-temperature brittleness temperature of the rubber conventionally used for manufacturing the air spring envelope and the rubber material parts of the three kinds of rubbers for manufacturing the air spring envelope prepared by the above three embodiments; a bursting test bench was used to test the bursting pressure of the rubber conventionally used for manufacturing the air spring envelope and the assembled parts of the three kinds of rubbers for manufacturing the air spring envelope prepared by the above three embodiments; an MTS bench fatigue test bench was used to test the bench fatigue of the rubber conventionally used for manufacturing the air spring envelope and the assembled parts of the three kinds of rubbers for manufacturing the air spring envelope prepared by the above three embodiments; the results shown in the following table were obtained.

[0055] Among them, for the airtightness test: the test temperature is 23 ± 3°C, the test medium is a mixture of 80% air and 20% helium, the pressure is 10 Bar, the test time is 45 seconds, and the evaluation criterion is ≤ 2.8×10 -5 mbar.l / s; for the low-temperature brittleness temperature test: it is tested according to Method C of ISO 812:2017(E); for the bursting pressure test: the test temperature is 23 ± 3°C, the test medium is water, the pressure increase rate is 5 Bar / min, and the evaluation criterion is > 35 bar; for the bench fatigue test: the test load is the maximum spring load, the test temperature cycles at -35°C, 50°C, and 80°C, the test frequency cycles at 0.4 Hz, 1.5 Hz, and 3 Hz, and the evaluation criterion is that the pressure loss within 24 hours should be less than 1 Bar, there are no harmful cracks causing airtightness problems, and the fatigue times > 3 million times.

[0056]

[0057] As can be seen from the data in the above table, the rubber for manufacturing the air spring envelope prepared by this method is slightly superior to the conventional envelope rubber in terms of tensile strength, elongation at break, and bursting resistance performance, and the low-temperature brittleness temperature is comparable. However, it has a significant improvement in airtightness and bench fatigue times compared with the conventional envelope rubber. Therefore, the envelope prepared from this rubber can ensure the long-term effectiveness of the fatigue durability of the air spring when applied to the air spring.

Claims

1. A method for preparing rubber for air spring bag skin, characterized in that The steps include: (1) Master batching in an internal mixer: first, 60-80 parts by weight of chloroprene rubber, 33-17 parts by weight of epoxidized natural rubber, and 7-3 parts by weight of styrene-butadiene rubber are put into an internal mixer, and the upper plug of the internal mixer is lowered for mixing; after mixing for 60 seconds, the upper plug is raised, and 3-5 parts by weight of magnesium oxide, 0.5-1.5 parts by weight of stearic acid, 3-5 parts by weight of a homogenizing agent, 4-6 parts by weight of an antioxidant, and 1 -2 parts by mass of protective wax, 1-3 parts by mass of polyethylene wax, 1-2 parts by mass of processing aid and 35-55 parts by mass of reinforcing filler, lower the top plug and continue mixing; after mixing for 15 seconds, raise the top plug, add 6-10 parts by mass of plasticizer, lower the top plug and continue mixing; when the mixing temperature reaches 115°C, raise the top plug for 15 seconds, then lower the top plug and mix to 125°C and discharge the glue to obtain a masterbatch rubber sheet; (2) leaving the masterbatch film at room temperature for 8 hours; (3) Final refining in an internal mixer: the master batch rubber sheet which has been left at room temperature for 8 hours is put into an internal mixer together with 4-6 parts by weight of zinc oxide, 0.5-1.5 parts by weight of an antioxidant, 4-6 parts by weight of an adhesive, 0.4-0.8 parts by weight of a vulcanizing agent, 2.5-3.5 parts by weight of an accelerator, and 0.2-0.4 parts by weight of a scorch retarder, and the upper top bolt is lowered for mixing. When the mixing temperature reaches 90° C., the upper top bolt is raised for 30 seconds, and then the upper top bolt is lowered for mixing to 100° C. and the rubber is discharged to obtain a final refining rubber sheet; (4) discharging the final refined rubber sheet obtained above on a two-roll open mill and leaving it at room temperature for 4 hours; (5) The final refined rubber sheet after being left at room temperature for 4 hours is calendered into a rubber sheet of a set thickness by a calendering machine, and a calendered cord fabric of a corresponding thickness is added to form a capsule; (6) placing the capsule obtained in the above step into a mold, closing the mold and vulcanizing for 10-15 minutes at a vulcanization temperature of 150-170° C. to obtain the desired rubber; The chloroprene rubber used in the step (1) is DCR 40A chloroprene rubber produced by Nippon Denka Chemical Co., Ltd.; The magnesium oxide used in step (1) is high-activity magnesium oxide RS-180; The homogenizing agent used in step (1) is 40MSF uniform tackifier; the polyethylene wax is BN-200 polyethylene wax; the processing aid is Haftolat / P processing aid; The antioxidant used in step (1) is a combination of OCTAMINE antioxidant and DTPD antioxidant; The reinforcing filler used in step (1) is a combination of VN3 white carbon black and N550 carbon black; The plasticizer used in the step (1) is Mediaplast PM plasticizer.

2. A method for preparing rubber for air spring bag skin according to claim 1, characterized in that The epoxidized natural rubber used in the step (1) is ENR 25 epoxidized natural rubber; and the styrene-butadiene rubber is SBR 1502 synthetic rubber.

3. The method for preparing rubber for air spring bag skin according to claim 1, characterized in that The antioxidant used in the step (3) is the antioxidant ZMTI.

4. The method for preparing the rubber for the air spring bag skin according to claim 1, characterized in that The adhesive used in step (3) is a combination of SCCTACK TR-1102 tackifying resin and SCCTACK ST-6000 phenolic tackifying resin.

5. The method for preparing rubber for air spring bag skin according to claim 1, characterized in that The vulcanizing agent used in the step (3) is insoluble sulfur IS60-75; the accelerator is a combination of N-cyclohexyl-2-benzothiazole sulfenamide and diethyl diphenyl thiuram disulfide.

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