Aging-resistant rubber sealing strip for automobiles and preparation method thereof

Abstract

The application relates to the technical field of automobile sealing strips, and discloses an anti-aging rubber sealing strip for automobiles and a preparation method thereof. The anti-aging rubber sealing strip for automobiles comprises the following components in parts by weight: ethylene-propylene-diene rubber 55-70 parts, ethylene-propylene-butadiene rubber 30-45 parts, an anti-aging agent 4-8 parts, a filling agent 35-60 parts, a softening agent 3-7 parts, a plasticizer 8-10 parts, an accelerator 1.2-2.5 parts, zinc oxide 4-8 parts, and a vulcanizing agent 1-2 parts. The anti-aging agent comprises diatomite-loaded tea polyphenol and diatomite-loaded anti-aging agent. The technical scheme can solve the problem of poor anti-aging property of the rubber sealing strip for automobiles in the prior art.

Description

Technical Field

[0001] This invention relates to the field of automotive sealing strip technology, specifically to an aging-resistant rubber sealing strip for automobiles and its preparation method. Background Technology

[0002] As a key component of automotive sealing systems, automotive rubber sealing strips serve functions such as waterproofing, sealing, sound insulation, dustproofing, shock absorption, and heat insulation. However, during prolonged use, rubber is exposed to oxygen, ultraviolet radiation, ozone, mechanical stress, heat, and aggressive chemicals, which accelerates its aging process. This leads to a gradual decrease in elasticity, hardening, and cracking of the sealing strips, ultimately resulting in poor sealing performance and affecting the normal use of the vehicle. Therefore, developing automotive rubber sealing strips with excellent aging resistance can not only improve the sealing performance of automobiles but also effectively extend their service life. Summary of the Invention

[0003] This invention proposes an aging-resistant rubber sealing strip for automobiles and its preparation method, which solves the problem of poor aging resistance of rubber sealing strips for automobiles in related technologies.

[0004] The technical solution of the present invention is as follows:

[0005] This invention proposes an aging-resistant rubber sealing strip for automobiles, comprising the following components in parts by weight: 55-70 parts of ethylene propylene diene monomer (EPDM) rubber, 30-45 parts of ethylene propylene diene monomer (EPDM) rubber, 3-8 parts of aging-resistant agent, 35-60 parts of filler, 3-7 parts of softener, 8-10 parts of plasticizer, 1.2-2.5 parts of accelerator, 4-8 parts of zinc oxide, and 1-2 parts of vulcanizing agent;

[0006] The anti-aging agent includes diatomaceous earth-loaded tea polyphenols and diatomaceous earth-loaded anti-aging agents in a mass ratio of 1:0.5~3.5.

[0007] As a further technical solution, the mass ratio of the diatomaceous earth-loaded tea polyphenols to the diatomaceous earth-loaded anti-aging agent is 1:1~2.

[0008] In the anti-aging agent of the automotive anti-aging rubber sealing strip of the present invention, when the mass ratio of diatomaceous earth loaded with tea polyphenols to diatomaceous earth loaded with anti-aging agent is 1:1~2, the anti-aging performance of the automotive sealing strip can be further improved.

[0009] As a further technical solution, the method for preparing diatomaceous earth-supported tea polyphenols includes the following steps:

[0010] S1. Dissolve tea polyphenols in anhydrous ethanol to obtain a tea polyphenol solution; add water to diatomaceous earth to obtain a diatomaceous earth dispersion.

[0011] S2. The tea polyphenol solution is added to the diatomaceous earth dispersion under stirring, a catalyst is added, the mixture is reacted, washed, and dried to obtain diatomaceous earth-supported tea polyphenols.

[0012] As a further technical solution, the preparation method of the diatomaceous earth-loaded antioxidant includes the following steps:

[0013] Diatomaceous earth was added to anhydrous ethanol, a silane coupling agent was added and stirred for the first time, an antioxidant was added, and a second stirring was carried out under nitrogen protection. After centrifugation, washing, and drying, diatomaceous earth-loaded antioxidant was obtained.

[0014] In the anti-aging agent of the automotive anti-aging rubber sealing strip of this invention, the anti-aging agent can inhibit the aging process of the rubber sealing strip and ensure its performance. The porous structure of diatomaceous earth can provide a large number of adsorption sites for the anti-aging agent, so that the anti-aging agent can be uniformly dispersed in the system. Diatomaceous earth also acts as a physical barrier to slow down the diffusion rate of aging factors such as oxygen and moisture into the material. It works synergistically with the anti-aging agent to enhance the anti-aging performance of the rubber sealing strip.

[0015] As a further technical solution, the mass ratio of tea polyphenols to diatomaceous earth is 1:3~6.

[0016] In the anti-aging agent of the automotive anti-aging rubber sealing strip of the present invention, the mass ratio of tea polyphenols to diatomaceous earth is 1:3~6, and can be selected as 1:3, 1:4, 1:5, or 1:6.

[0017] As a further technical solution, the catalyst includes one of stannous octoate and dibutyltin dilaurate, preferably dibutyltin dilaurate.

[0018] As a further technical solution, the mass ratio of tea polyphenols to catalyst is 1:0.01~0.04.

[0019] As a further technical solution, the reaction temperature is 70~80℃ and the time is 10~12h.

[0020] As a further technical solution, the mass ratio of diatomaceous earth to antioxidant is 20:2~3.

[0021] As a further technical solution, the mass ratio of diatomaceous earth to anhydrous ethanol is 1:10~15.

[0022] As a further technical solution, the mass ratio of diatomaceous earth to silane coupling agent is 5:0.8~1.2.

[0023] As a further technical solution, the silane coupling agent is γ-chloropropyltrimethoxysilane or γ-aminopropyltrimethoxysilane.

[0024] As a further technical solution, the temperature of the first stirring is 55~65℃, the speed is 500~600rpm, and the time is 8~12h.

[0025] As a further technical solution, the temperature of the second stirring is 70~85℃, the speed is 700~800rpm, and the time is 8~12h.

[0026] As a further technical solution, the centrifugation speed is 1000~1200 rpm and the time is 10~15 min.

[0027] As a further technical solution, the drying temperature is 80~100℃ and the time is 10~12h.

[0028] As a further technical solution, the antioxidant includes one or both of antioxidant 445 and antioxidant KY-845.

[0029] As a further technical solution, when the antioxidant is antioxidant 445 and antioxidant KY-845, the mass ratio of antioxidant KY-845 and antioxidant 445 is 1:1~2.5.

[0030] In the anti-aging agent of the automotive anti-aging rubber sealing strip of the present invention, antioxidant 445 and antioxidant KY-845 are loaded on diatomaceous earth. Antioxidant 445 is an amine antioxidant, and antioxidant KY-845 is a hindered phenolic antioxidant. When the two are used in combination, they can jointly inhibit the aging of the material and significantly improve the aging resistance of the material. Moreover, when the mass ratio of antioxidant KY-845 to antioxidant 445 is 1:1 to 2.5, the aging resistance of the prepared automotive rubber sealing strip is even better.

[0031] As a further technical solution, the filler includes one or both of carbon black and calcium carbonate.

[0032] As a further technical solution, the softener includes one or both of paraffin oil and naphthenic oil.

[0033] As a further technical solution, the plasticizer includes one or both of plasticizer DOP and plasticizer DOS.

[0034] In the automotive aging-resistant rubber sealing strip of the present invention, the addition of plasticizer can increase the flexibility and plasticity of the rubber. The plasticizer can be one or more conventional plasticizers in the art, such as plasticizer DOP, plasticizer TCP, plasticizer DOA, plasticizer DOS, etc. Preferably, the plasticizer is one or both of plasticizer DOP and plasticizer DOS.

[0035] As a further technical solution, the accelerator includes one or both of accelerator CZ and accelerator D.

[0036] As a further technical solution, the vulcanizing agent includes sulfur.

[0037] This invention also proposes a method for preparing an automotive aging-resistant rubber sealing strip, comprising the following steps:

[0038] After the first mixing of EPDM rubber and EPDM rubber, the aging resistant agent, filler, softener, plasticizer, accelerator and zinc oxide are added in sequence for the second mixing. Finally, the vulcanizing agent is added for the third mixing to obtain the compound rubber.

[0039] The compounded rubber is vulcanized to obtain an aging-resistant rubber sealing strip for automobiles.

[0040] The working principle and beneficial effects of this invention are as follows:

[0041] In this invention, the anti-aging agent uses diatomaceous earth loaded with tea polyphenols and diatomaceous earth loaded with antioxidants, which significantly improves the anti-aging properties of automotive rubber sealing strips. The diatomaceous earth loaded with tea polyphenols possesses antioxidant properties, capable of capturing free radicals generated by the thermo-oxidative action of rubber molecular chains, thus slowing down the aging process of the molecular chains and fundamentally improving the thermo-oxidative aging resistance of the rubber sealing strips. The addition of the diatomaceous earth loaded with antioxidants further enhances the UV resistance of the rubber sealing strips. By loading the antioxidants and tea polyphenols onto diatomaceous earth respectively, the migration resistance and long-term stability of the antioxidants and tea polyphenols are improved. The diatomaceous earth loaded with tea polyphenols and the diatomaceous earth loaded with antioxidants synergistically improve the anti-aging properties of automotive rubber sealing strips. Detailed Implementation

[0042] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] In the following embodiments and comparative examples,

[0044] Ethylene propylene diene monomer (EPDM) rubber: Model EP11A, manufactured by Shanghai Oushuo Plastics Co., Ltd.

[0045] EPDM rubber: Model 3722P, manufactured by Shanghai Oushuo Plastics Co., Ltd.

[0046] Diatomaceous earth: specific surface area 1m² 2 / g, manufactured by Wuhan Xinyongqing Chemical Co., Ltd.;

[0047] Tea polyphenols: food grade, manufactured by Henan Chengqi Food Co., Ltd.

[0048] Example 1

[0049] An automotive aging-resistant rubber sealing strip comprises the following components in parts by weight: 55 parts of ethylene propylene diene monomer (EPDM) rubber, 45 parts of ethylene propylene diene monomer (EPDM) rubber, 4 parts of aging-resistant agent, 21 parts of carbon black, 14 parts of calcium carbonate, 3 parts of paraffin oil, 5 parts of plasticizer DOP, 3 parts of plasticizer DOS, 1.2 parts of accelerator CZ, 4 parts of zinc oxide, and 1 part of sulfur.

[0050] The anti-aging agent includes diatomaceous earth-loaded tea polyphenols and diatomaceous earth-loaded anti-aging agent in a mass ratio of 1:0.5;

[0051] A method for preparing diatomaceous earth-supported tea polyphenols includes the following steps:

[0052] S1. Dissolve tea polyphenols in anhydrous ethanol to obtain a tea polyphenol solution, wherein the mass ratio of tea polyphenols to anhydrous ethanol is 1:20; add water to diatomaceous earth (the mass ratio of diatomaceous earth to water is 1:8) to obtain a diatomaceous earth dispersion.

[0053] S2. The tea polyphenol solution was added to the diatomaceous earth dispersion at a speed of 200 rpm and stirred for 8 min. The mass ratio of tea polyphenol to diatomaceous earth was 1:3. Then, dibutyltin dilaurate catalyst was added. The mass ratio of tea polyphenol to catalyst was 1:0.01. The reaction was carried out at 70℃ for 12 h. After washing with deionized water, the mixture was dried at 80℃ for 15 h to obtain diatomaceous earth-supported tea polyphenols.

[0054] The preparation method of diatomaceous earth-loaded antioxidant includes the following steps:

[0055] Diatomaceous earth was added to anhydrous ethanol (the mass ratio of diatomaceous earth to anhydrous ethanol was 1:10), and γ-chloropropyltrimethoxysilane (the mass ratio of diatomaceous earth to γ-chloropropyltrimethoxysilane was 5:1.2) was added. The mixture was then stirred at 55°C and 600 rpm for 12 h. Antioxidant 445 (the mass ratio of diatomaceous earth to antioxidant 445 was 20:2) was added. The mixture was stirred at 70°C and 700 rpm for 12 h under nitrogen protection. The mixture was then centrifuged at 1000 rpm for 15 min, washed three times with anhydrous ethanol, and dried at 80°C for 12 h to obtain diatomaceous earth-loaded antioxidant.

[0056] The preparation method of automotive rubber sealing strips includes the following steps:

[0057] After the first mixing of EPDM rubber and EPDM rubber, the following are added in sequence: anti-aging agent, carbon black, calcium carbonate, paraffin oil, plasticizer DOP, plasticizer DOS, accelerator CZ, and zinc oxide for the second mixing. Finally, sulfur is added for the third mixing to obtain the compound rubber.

[0058] The compounded rubber is vulcanized to obtain an aging-resistant rubber sealing strip for automobiles.

[0059] Example 2

[0060] An automotive aging-resistant rubber sealing strip comprises the following components in parts by weight: 70 parts of ethylene propylene diene monomer (EPDM) rubber, 30 parts of ethylene propylene diene monomer (EPDM) rubber, 8 parts of aging-resistant agent, 40 parts of carbon black, 20 parts of calcium carbonate, 7 parts of naphthenic oil, 6 parts of plasticizer DOP, 4 parts of plasticizer DOS, 2.5 parts of accelerator D, 8 parts of zinc oxide, and 2 parts of sulfur;

[0061] The anti-aging agent includes diatomaceous earth-loaded tea polyphenols and diatomaceous earth-loaded anti-aging agent in a mass ratio of 1:3.5;

[0062] A method for preparing diatomaceous earth-supported tea polyphenols includes the following steps:

[0063] S1. Dissolve tea polyphenols in anhydrous ethanol to obtain a tea polyphenol solution, wherein the mass ratio of tea polyphenols to anhydrous ethanol is 1:25; add water to diatomaceous earth (the mass ratio of diatomaceous earth to water is 1:10) to obtain a diatomaceous earth dispersion.

[0064] S2. The tea polyphenol solution was added to the diatomaceous earth dispersion at a speed of 300 rpm and stirred for 9 min. The mass ratio of tea polyphenol to diatomaceous earth was 1:6. Then, dibutyltin dilaurate catalyst was added. The mass ratio of tea polyphenol to catalyst was 1:0.04. The reaction was carried out at 80℃ for 10 h. After washing with deionized water, the mixture was dried at 100℃ for 12 h to obtain diatomaceous earth-supported tea polyphenols.

[0065] The preparation method of diatomaceous earth-loaded antioxidant includes the following steps:

[0066] Diatomaceous earth was added to anhydrous ethanol (the mass ratio of diatomaceous earth to anhydrous ethanol was 1:15), and γ-chloropropyltrimethoxysilane (the mass ratio of diatomaceous earth to γ-chloropropyltrimethoxysilane was 5:0.8) was added. The mixture was then stirred at 65°C and 500 rpm for 8 h. Antioxidant 445 (the mass ratio of diatomaceous earth to antioxidant 445 was 20:3) was added. The mixture was stirred at 85°C and 800 rpm for 8 h under nitrogen protection. The mixture was then centrifuged at 1200 rpm for 10 min, washed three times with anhydrous ethanol, and dried at 100°C for 10 h to obtain diatomaceous earth-loaded antioxidant.

[0067] The preparation method of automotive rubber sealing strips includes the following steps:

[0068] After the first mixing of EPDM rubber and EPDM rubber, the aging resistant agent, carbon black, calcium carbonate, naphthenic oil, plasticizer DOP, plasticizer DOS, accelerator D, and zinc oxide are added in sequence for the second mixing. Finally, sulfur is added for the third mixing to obtain the compound rubber.

[0069] The compounded rubber is vulcanized to obtain an aging-resistant rubber sealing strip for automobiles.

[0070] Example 3

[0071] An aging-resistant rubber sealing strip for automobiles and its preparation method, comprising the following components: 60 parts of ethylene propylene rubber, 40 parts of EPDM rubber, 6 parts of aging-resistant agent, 35 parts of carbon black, 15 parts of calcium carbonate, 3 parts of paraffin oil, 2 parts of naphthenic oil, 5 parts of plasticizer DOP, 3 parts of plasticizer DOS, 1.5 parts of accelerator CZ, 0.5 parts of accelerator D, 5 parts of zinc oxide, and 1.5 parts of sulfur;

[0072] Anti-aging agents include diatomaceous earth-loaded tea polyphenols and diatomaceous earth-loaded anti-aging agents in a mass ratio of 1:3;

[0073] A method for preparing diatomaceous earth-supported tea polyphenols includes the following steps:

[0074] S1. Dissolve tea polyphenols in anhydrous ethanol to obtain a tea polyphenol solution, wherein the mass ratio of tea polyphenols to anhydrous ethanol is 1:23; add water to diatomaceous earth (the mass ratio of diatomaceous earth to water is 1:9) to obtain a diatomaceous earth dispersion.

[0075] S2. The tea polyphenol solution was added to the diatomaceous earth dispersion at a speed of 400 rpm and stirred for 10 min. The mass ratio of tea polyphenol to diatomaceous earth was 1:4. Then, dibutyltin dilaurate catalyst was added. The mass ratio of tea polyphenol to catalyst was 1:0.03. The reaction was carried out at 75℃ for 11 h. After washing with deionized water, the mixture was dried at 90℃ for 13 h to obtain diatomaceous earth-supported tea polyphenols.

[0076] The preparation method of diatomaceous earth-loaded antioxidant includes the following steps:

[0077] Diatomaceous earth was added to anhydrous ethanol (the mass ratio of diatomaceous earth to anhydrous ethanol was 1:12), and γ-chloropropyltrimethoxysilane (the mass ratio of diatomaceous earth to γ-chloropropyltrimethoxysilane was 5:0.6) was added. The mixture was then stirred at 60℃ and 550 rpm for 10 h. Antioxidant 445 (the mass ratio of diatomaceous earth to antioxidant 445 was 20:2.5) was added. The mixture was stirred at 80℃ and 850 rpm for 10 h under nitrogen protection. The mixture was then centrifuged at 1100 rpm for 12 min, washed three times with anhydrous ethanol, and dried at 90℃ for 11 h to obtain diatomaceous earth-loaded antioxidant.

[0078] The preparation method of automotive rubber sealing strips includes the following steps:

[0079] After the first mixing of EPDM rubber and EPDM rubber, the following are added in sequence: anti-aging agent, carbon black, calcium carbonate, paraffin oil, naphthenic oil, plasticizer DOP, plasticizer DOS, accelerator CZ, accelerator D, and zinc oxide for the second mixing. Finally, sulfur is added for the third mixing to obtain the compound rubber.

[0080] The compounded rubber is vulcanized to obtain an aging-resistant rubber sealing strip for automobiles.

[0081] Example 4

[0082] The only difference between this embodiment and Embodiment 3 is that the anti-aging agent includes diatomaceous earth-loaded tea polyphenols and diatomaceous earth-loaded anti-aging agent in a mass ratio of 1:2.

[0083] Example 5

[0084] The only difference between this embodiment and Embodiment 3 is that the anti-aging agent includes diatomaceous earth-loaded tea polyphenols and diatomaceous earth-loaded anti-aging agent in a mass ratio of 1:1.

[0085] Example 6

[0086] The only difference between this embodiment and Embodiment 3 is that the anti-aging agent includes diatomaceous earth-loaded tea polyphenols and diatomaceous earth-loaded anti-aging agent in a mass ratio of 1:0.5.

[0087] Example 7

[0088] The only difference between this embodiment and Embodiment 4 is that, in the preparation of the diatomaceous earth-loaded antioxidant, antioxidant 445 is replaced with antioxidant KY-845.

[0089] Example 8

[0090] The only difference between this embodiment and Embodiment 4 is that when preparing the diatomaceous earth-loaded antioxidant, antioxidant 445 is replaced with a composite antioxidant, which is antioxidant KY-845 and antioxidant 445 in a mass ratio of 1:0.5.

[0091] Example 9

[0092] The only difference between this embodiment and Embodiment 4 is that when preparing the diatomaceous earth-loaded antioxidant, antioxidant 445 is replaced with a composite antioxidant, which is antioxidant KY-845 and antioxidant 445 in a mass ratio of 1:1.

[0093] Example 10

[0094] The only difference between this embodiment and Embodiment 4 is that, in the preparation of the diatomaceous earth-loaded antioxidant, antioxidant 445 is replaced with a composite antioxidant, which is antioxidant KY-845 and antioxidant 445 in a mass ratio of 1:2.5.

[0095] Example 11

[0096] The only difference between this embodiment and Embodiment 4 is that when preparing the diatomaceous earth-loaded antioxidant, antioxidant 445 is replaced with a composite antioxidant, which is antioxidant KY-845 and antioxidant 445 in a mass ratio of 1:3.

[0097] Comparative Example 1

[0098] The only difference between this comparative example and Example 3 is that the diatomaceous earth-loaded tea polyphenols are replaced with diatomaceous earth-loaded anti-aging agents.

[0099] Comparative Example 2

[0100] The only difference between this comparative example and Example 3 is that the diatomaceous earth-loaded antioxidant is replaced with diatomaceous earth-loaded tea polyphenols. The automotive rubber sealing strips prepared in Examples 1-11 and Comparative Examples 1-2 were tested according to the following methods:

[0101] 1. Tensile strength and elongation at break: determined according to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", using dumbbell-shaped type 1 specimens.

[0102] 2. Hot air aging performance: According to GB / T 3512-2014 "Accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber in hot air", the aging temperature is 125℃ and the time is 168h;

[0103] 3. Ultraviolet aging performance: Tested according to GB / T 16585-1996 "Artificial weathering (fluorescent ultraviolet lamp) test method for vulcanized rubber", with an exposure time of 24h and an ultraviolet light wavelength of 280nm;

[0104] The test results are shown in Table 1:

[0105] Table 1 Performance test results of automotive rubber sealing strips prepared in Examples 1-11 and Comparative Examples 1-2

[0106]

[0107] 1. Compared with Comparative Examples 1-2, the change rate of tensile strength of the automotive rubber sealing strips prepared in Examples 1-11 after thermo-oxidative aging test and UV aging test is less than -4.86%, indicating that the combination of diatomaceous earth loaded with tea polyphenols and diatomaceous earth loaded with antioxidant can effectively improve the aging resistance of automotive rubber sealing strips.

[0108] 2. Compared with Examples 3 to 6, the change rate of tensile strength of the automotive rubber sealing strips prepared in Examples 4 to 5 after thermo-oxidative aging test and UV aging test was lower than that of Examples 3 and 6, both below -3.31%. This indicates that the mass ratio of diatomaceous earth loaded with tea polyphenols to diatomaceous earth loaded with antioxidant is 1:1 to 2, which further improves the aging resistance of the automotive rubber sealing strips.

[0109] 3. Compared with Examples 7-11, the change rate of tensile strength of the automotive rubber sealing strips prepared in Examples 9-10 after thermo-oxidative aging test and UV aging test was significantly lower than that of Examples 4, 7-8 and 11, all below -2.25%. This indicates that when antioxidant KY-845 and antioxidant 445 are used in combination and the mass ratio of the two is 1:1 to 2.5, the aging resistance of the automotive rubber sealing strip is significantly improved.

[0110] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An aging-resistant rubber sealing strip for automobiles, characterized in that, It includes the following components in parts by weight: 55-70 parts of ethylene propylene diene monomer (EPDM) rubber, 30-45 parts of ethylene propylene diene monomer (EPDM) rubber, 3-8 parts of anti-aging agent, 35-60 parts of filler, 3-7 parts of softener, 8-10 parts of plasticizer, 1.2-2.5 parts of accelerator, 4-8 parts of zinc oxide, and 1-2 parts of vulcanizing agent; The anti-aging agent includes diatomaceous earth-loaded tea polyphenols and diatomaceous earth-loaded anti-aging agent in a mass ratio of 1:0.5~3.5; The method for preparing diatomaceous earth-supported tea polyphenols includes the following steps: S1. Dissolve tea polyphenols in anhydrous ethanol to obtain a tea polyphenol solution; add water to diatomaceous earth to obtain a diatomaceous earth dispersion. S2. The tea polyphenol solution is added to the diatomaceous earth dispersion under stirring, a catalyst is added, the mixture is reacted, washed, and dried to obtain diatomaceous earth-supported tea polyphenols.

2. The automotive aging-resistant rubber sealing strip according to claim 1, characterized in that, The mass ratio of diatomaceous earth-loaded tea polyphenols to diatomaceous earth-loaded anti-aging agents is 1:1~2.

3. The automotive aging-resistant rubber sealing strip according to claim 1, characterized in that, The preparation method of the diatomaceous earth-loaded antioxidant includes the following steps: Diatomaceous earth was added to anhydrous ethanol, a silane coupling agent was added and stirred for the first time, an antioxidant was added, and a second stirring was carried out under nitrogen protection. After centrifugation, washing, and drying, diatomaceous earth-loaded antioxidant was obtained.

4. The automotive aging-resistant rubber sealing strip according to claim 1, characterized in that, The mass ratio of tea polyphenols to diatomaceous earth is 1:3~6; The catalyst includes one of stannous octoate and dibutyltin dilaurate; The mass ratio of tea polyphenols to catalyst is 1:0.01~0.04; The reaction is carried out at a temperature of 70-80°C for 10-12 hours.

5. The automotive aging-resistant rubber sealing strip according to claim 3, characterized in that, The mass ratio of diatomaceous earth to antioxidant is 20:2~3; The mass ratio of diatomaceous earth to silane coupling agent is 5:0.8~1.2; The temperature of the first stirring is 55~65℃, the speed is 500~600rpm, and the time is 8~12h; The second stirring is performed at a temperature of 70-85℃, a speed of 700-800 rpm, and a time of 8-12 hours.

6. The automotive aging-resistant rubber sealing strip according to claim 3, characterized in that, The antioxidant includes one or both of antioxidant 445 and antioxidant KY-845.

7. The automotive aging-resistant rubber sealing strip according to claim 6, characterized in that, When the antioxidant is antioxidant 445 and antioxidant KY-845, the mass ratio of antioxidant KY-845 and antioxidant 445 is 1:1 to 2.

5.

8. The automotive aging-resistant rubber sealing strip according to claim 1, characterized in that, The filler includes one or both of carbon black and calcium carbonate; The softener includes one or both of paraffin oil and naphthenic oil; The plasticizer includes one or both of plasticizer DOP and plasticizer DOS; The accelerator includes one or both of accelerator CZ and accelerator D; The vulcanizing agent includes sulfur.

9. A method for preparing an automotive aging-resistant rubber sealing strip, used to prepare the automotive aging-resistant rubber sealing strip according to any one of claims 1 to 8, characterized in that, Includes the following steps: After the first mixing of EPDM rubber and EPDM rubber, the aging resistant agent, filler, softener, plasticizer, accelerator and zinc oxide are added in sequence for the second mixing. Finally, the vulcanizing agent is added for the third mixing to obtain the compound rubber. The compounded rubber is vulcanized to obtain an aging-resistant rubber sealing strip for automobiles.

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