A high-performance automotive rubber material that adapts to environmental changes

Abstract

The present invention discloses a high-performance automotive rubber material that is adaptive to environmental changes, and belongs to the technical field of rubber materials. The raw materials of the automotive rubber material include, by weight, 130-150 parts of natural rubber, 50-70 parts of nitrile rubber, 30-50 parts of composite fillers, 15-30 parts of EPDM rubber, 12-20 parts of additives, 1-5 parts of vulcanizing agents, 1-5 parts of accelerators, 1-3 parts of activators, and 0.01-0.1 parts of initiators. The introduction of composite fillers enables the automotive rubber material to maintain good wear resistance, aging resistance, and mechanical properties under high and low temperature environments, and adapt to environmental changes; the additives contain diaryl secondary amine structures, chitosan, and phosphorus and nitrogen flame retardant elements, and the additives act as a bridge, connecting the composite fillers and EPDM rubber. Therefore, the automotive rubber material of the present invention has excellent and stable mechanical properties, odor absorption performance, flame retardancy, aging resistance, wear resistance, and antibacterial properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of rubber materials, and in particular relates to a high-performance automotive rubber material that is adaptive to environmental changes. Background Art

[0002] In addition to tires, cars have 200-300 other rubber parts or sub-parts. Therefore, rubber materials are an essential component of a car and play a vital role in ensuring its performance and safety. There are many types of automotive rubber materials, including nitrile rubber, chloroprene rubber, acrylic rubber, silicone rubber, fluororubber, butyl rubber, natural rubber, and styrene-butadiene rubber.

[0003] Chinese patent CN118994800A discloses a rubber material for automobiles and a preparation method thereof. The raw materials of the rubber material for automobiles include, by weight, 60-70 parts of EPDM rubber, 6-10 parts of methyl vinyl phenyl silicone rubber, 30-40 parts of natural rubber, 8-10 parts of epoxidized natural rubber, 2-4 parts of an antioxidant, 2-4 parts of sulfur, 2-4 parts of lignin, 2-4 parts of pretreated plant fibers, 10-20 parts of seaweed extract, 5-10 parts of bamboo leaf extract, 1-2 parts of nano zinc oxide, 1-2 parts of activated carbon, 10-30 parts of modified bentonite, and 1-3 parts of carbon black. The rubber material for automobiles has excellent heat resistance, aging resistance, flame retardancy, and wear resistance, and has a low irritating odor, thus having good overall performance. However, because the raw materials used to make this rubber material are simply physically mixed, without any chemical reaction, the material's pungent odor becomes increasingly noticeable over time. Its heat resistance, aging resistance, flame retardancy, and wear resistance also become increasingly unstable, and its environmental adaptability deteriorates. Therefore, there is an urgent need to address these issues in order to meet the growing demands of automotive rubber material technology. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a high-performance automotive rubber material that is self-adaptive to environmental changes.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A high-performance automotive rubber material that is adaptive to environmental changes comprises the following raw materials in parts by weight: 130-150 parts of natural rubber, 50-70 parts of nitrile rubber, 30-50 parts of composite filler, 15-30 parts of EPDM rubber, 12-20 parts of additives, 1-5 parts of vulcanizing agent, 1-5 parts of accelerator, 1-3 parts of activator, and 0.01-0.1 parts of initiator.

[0007] Furthermore, the composite filler is prepared by the following steps:

[0008] The inorganic filler was dispersed in a mixed solution of anhydrous ethanol and deionized water, and the coupling agent was slowly added after stirring evenly. After the addition was completed, the temperature was raised to 65°C and stirred for 2 hours. The filtrate was filtered to remove the filtrate, and the filter residue was dried at 100°C for 12 hours to obtain a composite filler; the mass ratio of the inorganic filler to the coupling agent was 15:1.

[0009] Furthermore, the inorganic filler is a mixture of white carbon black, carbon black, light calcium carbonate and zinc oxide in a mass ratio of (1-2):3:(1-2):2.

[0010] Furthermore, the coupling agent is 3-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0011] White carbon black can enhance the mechanical properties of automotive rubber materials, improve their wear resistance and anti-aging properties. Light calcium carbonate plays the main role of filling, reinforcing, improving processing performance, improving the mechanical properties of rubber and adjusting rubber properties in automotive rubber materials, while effectively reducing production costs. Carbon black can enhance the strength and hardness of automotive rubber materials, making them have better wear resistance and aging resistance; it can also enhance the oil resistance, chemical resistance, as well as mechanical properties such as tear resistance, compression resistance, and shear resistance of automotive rubber materials; in addition, carbon black, as a UV absorber, can prevent rubber products from aging due to long-term exposure to sunlight; in addition, carbon black can improve the heat resistance and cold resistance of rubber, so that it can still maintain good performance in high or low temperature environments, and thus the rubber material of the present invention has high environmental adaptability.

[0012] Zinc oxide can not only improve the mechanical properties of automotive rubber materials such as tensile strength, tear strength and wear resistance, as well as heat resistance, but also directly participate in the cross-linking reaction of rubber molecular chains to form a three-dimensional network structure, thereby improving the performance of the rubber, making it more durable and extending its service life.

[0013] Furthermore, the auxiliary agent is prepared by the following steps:

[0014] S1. Under nitrogen protection, tris(2-chloropropyl) phosphate, triethylamine, and toluene were added to a three-necked flask, stirred to dissolve, and then N-methyl-4-penten-1-amine was slowly added. After the addition was complete, the temperature was raised to 70° C. and stirred for reaction for 5 h. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure to obtain intermediate 1; the amount ratio of tris(2-chloropropyl) phosphate, N-methyl-4-penten-1-amine, triethylamine, and toluene was 38 mL:30.5 g:44 mL:200 mL;

[0015] Triethylamine is used as an acid-binding agent, and the molar ratio of tris(2-chloropropyl) phosphate and N-methyl-4-penten-1-amine is controlled to be 1:2.0-2.1. The -Cl of tris(2-chloropropyl) phosphate and the -NH- of N-methyl-4-penten-1-amine undergo a disubstitution reaction. The reaction process is as follows:

[0016]

[0017] S2. Under nitrogen protection, add intermediate 1, pyridine and dimethyl sulfoxide into a three-necked flask, stir and dissolve, then slowly add 2-amino-4,6-dichloro-S-triazine, stir and react at room temperature for 3 hours after the addition is complete, and evaporate under reduced pressure to obtain intermediate 2; the amount ratio of intermediate 1, 2-amino-4,6-dichloro-S-triazine, pyridine and dimethyl sulfoxide is 56.4g:19.8g:11.6mL:240mL;

[0018] Pyridine is used as an acid-binding agent, and the molar ratio of intermediate 1 to 2-amino-4,6-dichloro-S-triazine is controlled to be 1.0-1.05:1. The -Cl of intermediate 1 and the -NH2 of 2-amino-4,6-dichloro-S-triazine undergo a substitution reaction. The reaction process is as follows:

[0019]

[0020] S3. Under nitrogen protection, intermediate 2, pyridine and dimethyl sulfoxide were added to a three-necked flask, stirred and dissolved, and then p-aminodiphenylamine was slowly added. After the addition was completed, the mixture was stirred and reacted at room temperature for 3 hours. After the reaction was completed, distillation was carried out under reduced pressure to obtain intermediate 3; the amount ratio of intermediate 2, p-aminodiphenylamine, pyridine and dimethyl sulfoxide was 58g:18.3mL:9.3mL:250mL;

[0021] Pyridine is used as an acid-binding agent to control the molar ratio of intermediate 2 to p-aminodiphenylamine to be 1:1.05-1.1. The -Cl of intermediate 2 undergoes a substitution reaction with the -NH2 of p-aminodiphenylamine. The reaction process is as follows:

[0022]

[0023] S4. Dissolve chitosan in DMF (N,N-dimethylformamide) under nitrogen protection, stir evenly, add the mixed solution of intermediate 3 and DMF, then heat to 50°C and stir to react for 6 hours. During this period, adjust the pH value of the system to 7 with 10wt% sodium carbonate solution. After the reaction, cool to room temperature, wash with deionized water by centrifugation for 3 times, then with anhydrous ethanol by centrifugation for 3 times, and finally dry at 80°C for 12 hours to obtain the auxiliary agent; the amount ratio of chitosan to intermediate 3 is 6g:3g.

[0024] Under heating conditions, the -OH of chitosan and the -Cl of intermediate 3 undergo substitution reaction. The reaction process is as follows:

[0025]

[0026] The additive contains chitosan, which has a large number of amino and carboxyl functional groups in its molecular structure. These functional groups can interact with odor molecules to form a polymer film, thereby changing the permeability of odor molecules and achieving the effect of odor absorption. Adding the chitosan-containing additive to the automotive rubber material can enhance the odor absorption ability of the automotive rubber material. In addition, chitosan is a deacetylated product of the natural polysaccharide chitin, with abundant amino groups on its surface, which has broad-spectrum antibacterial properties. Chitosan mainly interacts with bacterial cell walls, causing cell membrane damage and killing bacteria. Therefore, the automotive rubber material of the present invention also has certain antibacterial properties.

[0027] The additive is rich in phosphorus and nitrogen, both halogen-free flame retardants, which work synergistically to impart excellent flame retardancy and smoke suppression properties. When heated, the additive undergoes endothermic reactions, such as dehydration and esterification. These reactions absorb significant amounts of heat, thereby lowering the temperature of the rubber material and slowing its thermal decomposition. Under high temperatures, the additive forms a porous carbon layer that isolates the rubber from air and heat, preventing further cracking and the generation of flammable gases. During the reaction, the additive produces non-combustible gases, such as water vapor and nitrogen, which dilute the oxygen and flammable gases surrounding the material, reducing their concentration and thus preventing combustion. The steam and non-combustible gases produced by the additive cause the molten system to expand and foam, forming a porous carbon layer. This foam layer provides excellent heat insulation, oxygen isolation, and smoke suppression, further enhancing the flame retardant effect.

[0028] The additive contains a diaryl secondary amine structure, which contains an active amine group. The amine group can react with the active oxygen free radicals in the rubber material to form a stable compound, thereby preventing the oxidative degradation of the rubber material. In addition, the structure also has the characteristics of a hydrogen atom donor and a free radical capture, which can improve the heat resistance and weather resistance of the rubber material. Therefore, the application of additives containing diaryl secondary amine structures in automotive rubber materials can effectively improve the protective effect of the rubber material against ozone cracking and flex fatigue.

[0029] The additive contains carbon-carbon double bonds, which can react chemically with the carbon-carbon double bonds of the EPDM side chain under the action of the initiator, so that the additive can stably exist in the rubber material and give full play to the effects of odor absorption, flame retardancy, anti-aging and antibacterial. In addition, the additive contains terminal amino and hydroxyl groups, which can react chemically with the epoxy groups on the surface of the composite filler, so that the additive acts as a bridge, connecting the composite filler and EPDM, so that the dispersion and stability of the composite filler are greatly improved, and the composite material can also give full play to its role, effectively protecting the rubber material, so that it can still maintain good wear resistance, aging resistance and mechanical properties in high or low temperature environments, and can adapt to environmental changes.

[0030] Furthermore, the vulcanizing agent is sulfur.

[0031] Furthermore, the accelerator is one or more of 2,2'-dibenzothiazole disulfide, tetramethylthiuram disulfide, 2-benzothiazolyl-N-morpholinyl sulfide, 2-mercaptobenzothiazole, and zinc diethyldithiocarbamate.

[0032] Furthermore, the activator is stearic acid.

[0033] Furthermore, the initiator is one or both of dicumyl peroxide and dibenzoyl peroxide.

[0034] Beneficial effects of the present invention:

[0035] 1. The introduction of composite fillers can enable automotive rubber materials to maintain good wear resistance, aging resistance and mechanical properties in high or low temperature environments, and adapt to environmental changes;

[0036] 2. The prepared auxiliary agent contains a diaryl secondary amine structure, chitosan and rich phosphorus and nitrogen halogen-free flame retardant elements, and the auxiliary agent acts as a bridge to connect the composite filler and EPDM rubber. Therefore, the automotive rubber material of the present invention has excellent and stable mechanical properties, odor adsorption performance, flame retardancy, aging resistance, wear resistance and antibacterial properties, etc., has excellent comprehensive performance and has broad market prospects. DETAILED DESCRIPTION

[0037] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] Example 1: Preparation of composite filler. The preparation steps are as follows:

[0039] 3 g of white carbon black, 9 g of carbon black, 3 g of light calcium carbonate, and 6 g of zinc oxide were dispersed in a mixed solution of 140 mL of anhydrous ethanol and 60 mL of deionized water. After stirring evenly, 1.4 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane was slowly added. After the addition was completed, the temperature was raised to 65 ° C, stirred for 2 h, the filtrate was filtered to remove the filtrate, and the filter residue was dried at 100 ° C for 12 h to obtain a composite filler.

[0040] Example 2: Preparation of composite filler. The preparation steps are as follows:

[0041] 4.5 g of white carbon black, 9 g of carbon black, 4.5 g of light calcium carbonate, and 6 g of zinc oxide were dispersed in a mixed solution of 140 mL of anhydrous ethanol and 60 mL of deionized water. After stirring evenly, 1.6 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane was slowly added. After the addition was completed, the temperature was raised to 65 ° C, stirred for 2 h, the filtrate was filtered to remove the filtrate, and the filter residue was dried at 100 ° C for 12 h to obtain a composite filler.

[0042] Example 3: Preparation of composite filler. The preparation steps are as follows:

[0043] 6 g of white carbon black, 9 g of carbon black, 6 g of light calcium carbonate, and 6 g of zinc oxide were dispersed in a mixed solution of 140 mL of anhydrous ethanol and 60 mL of deionized water. After stirring evenly, 1.8 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane was slowly added. After the addition was completed, the temperature was raised to 65 ° C, stirred for 2 h, the filtrate was filtered to remove the filtrate, and the filter residue was dried at 100 ° C for 12 h to obtain a composite filler.

[0044] Example 4, preparation of auxiliary agent, the specific steps are as follows:

[0045] S1. Under nitrogen protection, 38 mL of tris(2-chloropropyl) phosphate, 44 mL of triethylamine, and 200 mL of toluene were added to a 500 mL three-necked flask, stirred to dissolve, and then 30.5 g of N-methyl-4-penten-1-amine was slowly added. After the addition was complete, the temperature was raised to 70° C. and stirred for 5 h. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure to obtain intermediate 1;

[0046] S2. Under nitrogen protection, 56.4 g of intermediate 1, 11.6 mL of pyridine and 240 mL of dimethyl sulfoxide were added to a 500 mL three-necked flask, stirred and dissolved, and then 19.8 g of 2-amino-4,6-dichloro-S-triazine was slowly added. After the addition was completed, the mixture was stirred and reacted at room temperature for 3 h. After the reaction was completed, it was evaporated under reduced pressure to obtain intermediate 2;

[0047] S3. Under nitrogen protection, 58 g of intermediate 2, 9.3 mL of pyridine and 250 mL of dimethyl sulfoxide were added to a 500 mL three-necked flask, stirred and dissolved, and then 18.3 mL of p-aminodiphenylamine was slowly added. After the addition was completed, the mixture was stirred and reacted at room temperature for 3 h. After the reaction was completed, distillation was carried out under reduced pressure to obtain intermediate 3;

[0048] S4. Under nitrogen protection, 6 g of chitosan was dissolved in 100 mL of DMF, and after stirring evenly, a mixed solution of 3 g of intermediate 3 and 20 mL of DMF was added, and then the temperature was raised to 50 ° C and stirred for 6 h. During this period, the pH value of the system was adjusted to 7 by 10 wt% sodium carbonate solution. After the reaction was completed, it was cooled to room temperature, first centrifuged and washed 3 times with deionized water, then centrifuged and washed 3 times with anhydrous ethanol, and finally dried at 80 ° C for 12 h to obtain an auxiliary agent.

[0049] Example 5, preparing a rubber material for a vehicle, the specific steps are as follows:

[0050] 13 parts of natural rubber, 50 parts of nitrile rubber and 15 parts of EPDM rubber were added to an open mill for the first mixing. After the mixing was completed, 30 parts of the composite filler prepared in Example 1, 12 parts of the additive prepared in Example 4 and 0.01 parts of dicumyl peroxide were added for the second mixing. After the mixing was completed, the mixture was put into a flat vulcanizing press and 1 part of sulfur, 1 part of 2,2'-dibenzothiazole disulfide and 1 part of stearic acid were added for vulcanization. After the vulcanization was completed, a rubber material for automobile was obtained.

[0051] Example 6, preparing a rubber material for a vehicle, the specific steps are as follows:

[0052] 140 parts of natural rubber, 60 parts of nitrile rubber and 20 parts of EPDM rubber were added to an open mill for the first mixing. After the mixing was completed, 40 parts of the composite filler prepared in Example 2, 17 parts of the additive prepared in Example 4, and 0.07 parts of dibenzoyl peroxide were added for the second mixing. After the mixing was completed, the mixture was put into a flat vulcanizing press and 3 parts of sulfur, 2 parts of tetramethylthiuram disulfide, 1 part of 2-benzothiazolyl-N-morpholinyl sulfide, and 2 parts of stearic acid were added for vulcanization. After the vulcanization was completed, a rubber material for automobile was obtained.

[0053] Example 7, preparing a rubber material for a vehicle, the specific steps are as follows:

[0054] 150 parts of natural rubber, 70 parts of nitrile rubber and 30 parts of EPDM rubber were added to an open mill for the first mixing. After the mixing was completed, 50 parts of the composite filler prepared in Example 3, 20 parts of the additive prepared in Example 4 and 0.1 part of dibenzoyl peroxide were added for the second mixing. After the mixing was completed, the mixture was put into a flat vulcanizing press and 5 parts of sulfur, 2 parts of 2-mercaptobenzothiazole, 3 parts of zinc diethyldithiocarbamate and 3 parts of stearic acid were added for vulcanization. After the vulcanization was completed, a rubber material for automobile was obtained.

[0055] Comparative Example 1: Preparation of a rubber material for a vehicle, the specific steps are as follows:

[0056] The remaining steps remained unchanged, except that the additives in Example 5 were replaced by 2 parts of antioxidant 4020, 2 parts of flame retardant FRC-2, and 8 parts of chitosan to prepare a rubber material for automobiles.

[0057] Comparative Example 2: Preparation of a rubber material for a vehicle, the specific steps are as follows:

[0058] The remaining steps remained unchanged, except that the composite filler in Example 5 was replaced by 4.3 parts of white carbon black, 12.8 parts of carbon black, 4.3 parts of light calcium carbonate, and 8.6 parts of zinc oxide to prepare a rubber material for automobiles.

[0059] Performance Testing

[0060] The automotive rubber materials prepared in Examples 5-7 and Comparative Examples 1-2 were made into corresponding shapes according to different standards and subjected to the following performance tests:

[0061] The tensile strength was determined using the national standard GB / T 528-2009 "Rubber, vulcanized or thermoplastic - Determination of tensile stress-strain properties"; the tensile strength of the aged specimens was then determined according to the national standard GB / T 3512-2001 "Rubber, vulcanized or thermoplastic - Hot air accelerated aging and heat resistance test";

[0062] The limiting oxygen index of the sample was measured using the national standard GB / T 10707-2008 "Determination of Combustion Properties of Rubber"; the automotive rubber materials prepared in Examples 5-7 and Comparative Examples 1-2 were then allowed to stand at room temperature for 200 days before the limiting oxygen index was measured again;

[0063] The test results of all items are shown in the following table:

[0064]

[0065] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0066] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A high-performance automotive rubber material that is adaptive to environmental changes, characterized in that: The invention comprises the following raw materials in parts by weight: 130-150 parts of natural rubber, 50-70 parts of nitrile rubber, 30-50 parts of composite filler, 15-30 parts of EPDM rubber, 12-20 parts of additives, 1-5 parts of vulcanizing agent, 1-5 parts of accelerator, 1-3 parts of activator, and 0.01-0.1 parts of initiator; Wherein, the composite filler is prepared by the following steps: The inorganic filler is dispersed in a mixed solution of anhydrous ethanol and deionized water, and a coupling agent is added after stirring. After the addition is completed, the temperature is raised to 65° C. and stirred for 2 hours. The filtrate is filtered to remove the filtrate, and the filter residue is dried at 100° C. for 12 hours to obtain a composite filler; the mass ratio of the inorganic filler to the coupling agent is 15:1; the inorganic filler is a mixture of white carbon black, carbon black, light calcium carbonate, and zinc oxide in a mass ratio of (1-2):3:(1-2):2; and the coupling agent is 3-(2,3-epoxypropoxy)propyltrimethoxysilane; The auxiliary agent is prepared by the following steps: S1. Under nitrogen protection, tri(2-chloropropyl) phosphate, triethylamine, and toluene were added to a flask, stirred, and N-methyl-4-penten-1-amine was added. The temperature was raised to 70° C. and stirred for 5 h. The mixture was cooled and distilled under reduced pressure to obtain intermediate 1. The amount ratio of tri(2-chloropropyl) phosphate, N-methyl-4-penten-1-amine, triethylamine, and toluene was 38 mL:30.5 g:44 mL:200 mL. S2. Under nitrogen protection, intermediate 1, pyridine and dimethyl sulfoxide were added to a flask, stirred, and 2-amino-4,6-dichloro-S-triazine was added. The mixture was stirred and reacted at room temperature for 3 hours, and distilled under reduced pressure to obtain intermediate 2; the amount ratio of intermediate 1, 2-amino-4,6-dichloro-S-triazine, pyridine and dimethyl sulfoxide was 56.4 g:19.8 g:11.6 mL:240 mL; S3. Under nitrogen protection, intermediate 2, pyridine and dimethyl sulfoxide were added to a flask, stirred, and p-aminodiphenylamine was added. The reaction was stirred at room temperature for 3 hours, and distilled under reduced pressure to obtain intermediate 3; the amount ratio of intermediate 2, p-aminodiphenylamine, pyridine and dimethyl sulfoxide was 58 g:18.3 mL:9.3 mL:250 mL; S4. Chitosan was dissolved in DMF under nitrogen protection, and a mixed solution of intermediate 3 and DMF was added after stirring. The temperature was raised to 50°C and stirred for 6 hours. During this period, the pH value of the system was adjusted to 7 with 10wt% sodium carbonate solution. After the reaction, the mixture was cooled to room temperature, washed by centrifugation 3 times with deionized water, then washed by centrifugation 3 times with anhydrous ethanol, and dried to obtain an auxiliary agent; the amount ratio of chitosan to intermediate 3 was 6g:3g.

2. The high-performance automotive rubber material that is adaptive to environmental changes according to claim 1, characterized in that: The vulcanizing agent is sulfur.

3. The high-performance automotive rubber material that is adaptive to environmental changes according to claim 1, characterized in that: The accelerator is one or more of 2,2'-dibenzothiazole disulfide, tetramethylthiuram disulfide, 2-benzothiazolyl-N-morpholinyl sulfide, 2-mercaptobenzothiazole, and zinc diethyldithiocarbamate.

4. The high-performance automotive rubber material that is adaptive to environmental changes according to claim 1, characterized in that: The activator is stearic acid; the initiator is one or both of dicumyl peroxide and dibenzoyl peroxide.

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