Benzyltoluene-containing high-stability tire rubber and preparation method thereof

Abstract

The invention relates to the technical field of tires, in particular to benzyltoluene-containing high-stability tire rubber and a preparation method thereof, and the benzyltoluene-containing high-stability tire rubber comprises the following raw materials in parts by mass: 40-70 parts of a composite rubber composition, 5-25 parts of a plasticizer, 10-15 parts of an auxiliary agent, 2-5 parts of a vulcanizing agent, 0.5-1.5 parts of a vulcanization accelerator and 1-4 parts of stearic acid. The tire rubber disclosed by the invention has relatively good wear resistance, mechanical property, anti-aging property and self-repairing capability.

Description

Technical Field

[0001] This invention relates to the field of tire technology, and in particular to a highly stable tire rubber containing benzyltoluene and its preparation method. Background Technology

[0002] The development of high-stability tire rubber stems from the automotive industry's continuous pursuit of safety, durability, and environmental performance. As the only component of a vehicle in contact with the road surface, tire stability directly affects driving safety, energy efficiency, and ride comfort. Traditional rubber materials are prone to aging, deformation, or decreased grip under extreme temperatures, complex road conditions, and long-term stress. Especially in high-speed driving or heavy-load scenarios, the risk of delamination and tire blowout due to tire heat generation is significant. With the popularization of new energy vehicles and the increasing demand for extreme operating conditions, the heat resistance, wear resistance, and structural stability of materials have become the core areas for technological breakthroughs.

[0003] The diversity of rubber is reflected in its classification and properties: natural rubber is known for its excellent elasticity and strength, while synthetic rubber focuses on properties such as oil resistance and temperature resistance (-120℃ to 100℃). For example, fluororubber is corrosion-resistant, and silicone rubber has outstanding insulation properties. Its core processing technologies include mixing, calendering, and vulcanization. Vulcanization, through cross-linking molecular chains with sulfur or peroxides, significantly improves the material's elasticity and durability. In terms of applications, rubber permeates many aspects of modern life: tires account for more than 70% of global rubber consumption, relying on their wear resistance and cushioning properties to ensure traffic safety; in the industrial sector, it is used in seals, shock absorbers, and conveyor belts to solve fluid leakage and mechanical stability problems; in construction, it is used in waterproofing materials and sound insulation layers; and in the medical field, it is used to manufacture biocompatible devices using silicone and other materials. However, there are still many problems to be solved in the application of rubber in the tire field. For example, patent number CN109456513B discloses "a wear-resistant tire rubber and its preparation method", which contains the following raw materials in parts by weight: 25-40 parts of natural rubber, 10-15 parts of butadiene rubber, 20-50 parts of styrene-butadiene rubber, 10-25 parts of carbon black, 5-15 parts of modified silicon carbide, 1-3 parts of vulcanizing agent, 1-4 parts of vulcanization accelerator, 2-5 parts of zinc oxide, 1-3 parts of stearic acid, 2-5 parts of antioxidant, and 2-3 parts of paraffin wax. This tire rubber uses the high wear resistance of modified silicon carbide to improve the wear resistance of the tire, reduce the thermo-oxidative aging of the rubber, and extend its service life. The wear-resistant tires prepared in this way have enhanced wear resistance, tear resistance, fast heat dissipation, high quality, and long service life. For example, patent number CN108752675B discloses "a low rolling resistance tire rubber composition and its application," which includes the following components by weight percentage: 10-35% solution-polymerized styrene-butadiene rubber; X% emulsified polymerized styrene-butadiene rubber, 0 < X ​​≤ 25%; Y% high cis polybutadiene, 0 < Y ≤ 15%; 2-25% reinforcing carbon black; 10-40% silica filler; 6-15% silane coupling agent; Z% hydrocarbon resin, 0 < Z ≤ 5%; and 2-18% plasticizing system, which includes amorphous silica spherical particles, zinc fatty acid salts, and processing oil. The components of this patent work together in a certain proportion, so that the rubber composition can improve tire rolling resistance and processability, and has a good performance trade-off between rolling resistance, grip, and wear resistance. It can also solve the problem of difficult processability when the amount of reinforcing filler is high, and is particularly suitable for use in high-performance tire tread rubber.

[0004] However, inorganic additives are usually added to rubber during daily use to improve its wear resistance. Inorganic additives have poor compatibility with the rubber system and are prone to migration and precipitation. In addition, rubber aging is also one of the factors that seriously affect the safety of use. Therefore, it is urgent to develop a tire rubber with good wear resistance and temperature resistance, good compatibility of each component, and excellent anti-aging properties. Summary of the Invention

[0005] The purpose of this invention is to provide a highly stable tire rubber containing benzyltoluene and its preparation method, so as to solve the problems of poor compatibility between inorganic additives and rubber systems, easy migration and precipitation, and poor anti-aging performance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: One aspect of the present invention provides a highly stable tire rubber containing benzyltoluene, comprising the following raw materials in parts by weight: 40-70 parts of a composite rubber composition, 5-25 parts of a plasticizer, 10-15 parts of an additive, 2-5 parts of a vulcanizing agent, 0.5-1.5 parts of a vulcanization accelerator, and 1-4 parts of stearic acid.

[0007] This application uses a composite rubber composition, plasticizer, additives, vulcanizing agent, vulcanization accelerator and stearic acid as the main raw materials. The components have good compatibility. At the same time, the tire rubber produced has good wear resistance and temperature resistance, as well as good self-healing effect and anti-aging properties.

[0008] In some embodiments, the composite rubber composition is composed of styrene-butadiene rubber and natural rubber.

[0009] This application uses a blend of styrene-butadiene rubber (SBR) and natural rubber as a rubber composition. The SBR and natural rubber form a "rigid-flexible" network structure. The flexible chains of natural rubber can absorb deformation energy, while the rigid chains of SBR can disperse stress and reduce dynamic fatigue heat generation.

[0010] In some embodiments, the mass ratio of the styrene-butadiene rubber to natural rubber is 1:(1~1.3).

[0011] Preferably, the mass ratio of the styrene-butadiene rubber to natural rubber is 1:1.2.

[0012] In some embodiments, the plasticizer is polybenzyltoluene.

[0013] This application uses polybenzyltoluene as a plasticizer. Polybenzyltoluene significantly reduces the viscosity of rubber compound, improves the fluidity of the rubber compound, and promotes the uniform dispersion of compounding agents such as vulcanizing agents and fillers, thereby improving production efficiency. Polybenzyltoluene participates in the vulcanization reaction system and optimizes the elastic modulus and resistance to vulcanization reversion of rubber by adjusting the crosslinking density. When applied in styrene-butadiene rubber formulations, it can significantly improve the heat aging resistance of tread and sidewall rubber.

[0014] In some embodiments, the preparation method of the auxiliary agent includes the following steps: S1. Carbon black, bis-[3-(triethoxysilyl)propyl]disulfide and 3-(trimethoxysilyl)-1-propanethiol are mixed and added to tetrahydrofuran. The mixture is heated to 55-65℃ under microwave power of 250-350W and stirred at a constant temperature for 0.5-1h. After the reaction is completed, the mixture is centrifuged, filtered, washed and dried to obtain modified carbon black. S2. Dissolve dopamine hydrochloride in Tris buffer, add copper nitrate and stir at room temperature to obtain a composite solution. Then add the modified carbon black obtained in step S1, stir vigorously for 20-30 minutes, centrifuge and filter, wash with deionized water, freeze dry to obtain the auxiliary agent.

[0015] Carbon black is a commonly used inorganic additive in the rubber industry. Carbon black can improve the wear resistance of rubber. However, inorganic additives have poor compatibility with polymer materials and are prone to agglomeration and precipitation, which affects the performance of rubber.

[0016] The additive in this application is obtained by using carbon black as the main raw material and modifying it with bis-[3-(triethoxysilyl)propyl]disulfide and 3-(trimethoxysilyl)-1-propanethiol to obtain a modified carbon black containing disulfide bonds. Subsequently, a layer of polydopamine is coated onto the surface of the modified carbon black to obtain the additive. This additive is uniformly dispersed in the rubber system. The presence of disulfide bonds in the additive enhances the self-healing ability of the rubber, and the phenolic structure improves the rubber's anti-aging ability.

[0017] In some embodiments, in step S1, the mass of the carbon black is 5 to 8 times the total mass of bis-[3-(triethoxysilyl)propyl]disulfide and 3-(trimethoxysilyl)-1-propanethiol.

[0018] Preferably, in step S1, the mass of the carbon black is 6 times the total mass of bis-[3-(triethoxysilyl)propyl]disulfide and 3-(trimethoxysilyl)-1-propanethiol.

[0019] In some embodiments, in step S1, the molar ratio of the bis-[3-(triethoxysilyl)propyl]disulfide to 3-(trimethoxysilyl)-1-propanethiol is 1:(1~3).

[0020] Preferably, in step S1, the molar ratio of bis-[3-(triethoxysilyl)propyl]disulfide to 3-(trimethoxysilyl)-1-propanethiol is 1:2.

[0021] In some embodiments, in step S2, the mass ratio of dopamine hydrochloride to modified carbon black is 1:(1~2).

[0022] Preferably, in step S2, the mass ratio of dopamine hydrochloride to modified carbon black is 1:1.5.

[0023] In some embodiments, the vulcanizing agent is sulfur.

[0024] In some embodiments, the vulcanization accelerator is NOBS.

[0025] Another aspect of the present invention provides a method for preparing a high-stability tire rubber containing benzyltoluene, comprising the following steps: feeding a composite rubber composition and additives into a mixer and mixing at 150-160°C for 4-6 minutes; then adding a plasticizer and stearic acid and continuing to mix at 150-160°C for 4-6 minutes; subsequently adding a vulcanizing agent and a vulcanization accelerator and mixing at 95-105°C for 3-5 minutes to obtain a high-stability tire rubber.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention is made from composite rubber composition, plasticizer, additives, vulcanizing agent, vulcanization accelerator and stearic acid as the main raw materials. The components have good compatibility and the tire rubber obtained has good wear resistance and temperature resistance, as well as good self-healing effect and anti-aging properties.

[0027] (2) The additive of the present invention uses carbon black as the main raw material and obtains modified carbon black containing disulfide bonds by using bis-[3-(triethoxysilyl)propyl]disulfide and 3-(trimethoxysilyl)-1-propanethiol as modifiers. Then, a layer of polydopamine is coated on the surface of the modified carbon black to obtain the additive. The additive is uniformly dispersed in the rubber system. At the same time, the additive contains disulfide bonds, which can improve the self-healing ability of rubber, and the phenolic structure can improve the anti-aging ability of rubber. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0029] Unless otherwise specified, those skilled in the art may select from the following post-processing operations, such as "mixing", "heating", "centrifugal filtration", "washing", "drying", "stirring", and "freeze-drying", based on actual conditions, without further limitation.

[0030] In the following embodiments, styrene-butadiene rubber was purchased from Jinan Shanhai Chemical Technology Co., Ltd.; natural rubber was purchased from Jining Juji New Materials Co., Ltd.

[0031] Preparation Example 1 The preparation method of the auxiliary agent includes the following steps: S1. 60g of carbon black, 3.3g of bis-[3-(triethoxysilyl)propyl]disulfide and 6.7g of 3-(trimethoxysilyl)-1-propanethiol were mixed and added to 700ml of tetrahydrofuran. The mixture was heated to 60℃ under microwave power of 300W and stirred for 0.7h. After the reaction was completed, the mixture was centrifuged and filtered, washed with tetrahydrofuran, and dried to obtain modified carbon black. S2. Dissolve 40g of dopamine hydrochloride in Tris buffer (prepared as a 2g / L solution), add 20mM copper nitrate and stir at room temperature to obtain a composite solution. Then add 60g of the modified carbon black obtained in step S1, stir vigorously (2000r / min) for 25min, centrifuge and filter, wash with deionized water, freeze dry to obtain the auxiliary agent.

[0032] Preparation Example 2 The preparation method of the additive is the same as that in Preparation Example 1, except that an equal amount of KH-550 silane coupling agent is used instead of bis-[3-(triethoxysilyl)propyl] disulfide.

[0033] Preparation Example 3 The preparation method of the additive includes the following steps: 60g of carbon black, 3.3g of bis-[3-(triethoxysilyl)propyl]disulfide and 6.7g of 3-(trimethoxysilyl)-1-propanethiol are mixed and added to 700ml of tetrahydrofuran. The mixture is heated to 60℃ under microwave power of 300W and stirred at a constant temperature for 0.7h. After the reaction is completed, the mixture is centrifuged and filtered, washed with tetrahydrofuran, and dried to obtain the additive.

[0034] Example 1 A highly stable tire rubber containing benzyltoluene comprises the following raw materials in parts by weight: 50 parts of a composite rubber composition, 15 parts of dibenzyltoluene, 13 parts of additives, 4 parts of sulfur, 1 part of accelerator NOBS, and 2 parts of octadecanoic acid.

[0035] The composite rubber composition is composed of styrene-butadiene rubber and natural rubber in a mass ratio of 1:1.2, and the additives are prepared by Preparation Example 1.

[0036] A method for preparing high-stability tire rubber containing benzyltoluene includes the following steps: a composite rubber composition and additives are fed into an internal mixer and mixed at 155°C for 5 minutes; then dibenzyltoluene and octadecanoic acid are added and mixed at 155°C for another 5 minutes; subsequently, sulfur and accelerator NOBS are added and mixed at 100°C for 4 minutes to obtain high-stability tire rubber.

[0037] Example 2 A highly stable tire rubber containing benzyltoluene comprises the following raw materials in parts by weight: 40 parts of a composite rubber composition, 5 parts of dibenzyltoluene, 10 parts of additives, 2 parts of sulfur, 0.5 parts of accelerator NOBS, and 1 part of octadecanoic acid.

[0038] The composite rubber composition is composed of styrene-butadiene rubber and natural rubber in a mass ratio of 1:1.2, and the additives are prepared by Preparation Example 1.

[0039] A method for preparing high-stability tire rubber containing benzyltoluene includes the following steps: a composite rubber composition and additives are fed into an internal mixer and mixed at 150°C for 4 minutes; then dibenzyltoluene and octadecanoic acid are added and mixed at 150°C for another 4 minutes; subsequently, sulfur and accelerator NOBS are added and mixed at 95°C for 3 minutes to obtain high-stability tire rubber.

[0040] Example 3 A highly stable tire rubber containing benzyltoluene comprises the following raw materials in parts by weight: 70 parts of a composite rubber composition, 25 parts of dibenzyltoluene, 15 parts of additives, 5 parts of sulfur, 1.5 parts of accelerator NOBS, and 4 parts of octadecanoic acid.

[0041] The composite rubber composition is composed of styrene-butadiene rubber and natural rubber in a mass ratio of 1:1.2, and the additives are prepared by Preparation Example 1.

[0042] A method for preparing high-stability tire rubber containing benzyltoluene includes the following steps: a composite rubber composition and additives are fed into an internal mixer and mixed at 160°C for 6 minutes; then dibenzyltoluene and octadecanoic acid are added and mixed at 160°C for another 6 minutes; subsequently, sulfur and accelerator NOBS are added and mixed at 105°C for 5 minutes to obtain high-stability tire rubber.

[0043] Example 4 A highly stable tire rubber containing benzyltoluene and its preparation method are described. The specific implementation method is the same as in Example 1, except that the additives are prepared in Preparation Example 2.

[0044] Example 5 A highly stable tire rubber containing benzyltoluene and its preparation method are described. The specific implementation method is the same as in Example 1, except that the additives are prepared in Preparation Example 3.

[0045] Example 6 A highly stable tire rubber containing benzyltoluene and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the composite rubber composition is composed of styrene-butadiene rubber and natural rubber in a mass ratio of 1:1.

[0046] Comparative Example 1 A highly stable tire rubber containing benzyltoluene and its preparation method are described. The specific implementation method is the same as in Example 1, except that carbon black is used as an additive.

[0047] Performance testing: (1) Akron wear: GB / T1689-2014 Determination of abrasion resistance of vulcanized rubber.

[0048] (2) Anti-aging performance: Rubber was made into 10mm×10mm×3mm test strips and placed in a JBS-100 aging chamber for hot air aging test at 70℃ for 24 hours. The elongation at break after aging was tested using an Instron3369 tensile testing machine.

[0049] (3) Repair ability: The rubber was made into a test strip with a thickness of 1 mm, a scratch of 5 mm and a depth of 50 μm, and self-repaired at 90℃ for 24 h. The tensile strength before and after repair was tested, and the self-repair rate was calculated.

[0050] The tire rubber samples of each embodiment and comparative example were tested according to the above method, and the test results are shown in Table 1.

[0051] Table 1

[0052] According to the data in Table 1, the tire rubbers prepared in Examples 1-3 have good wear resistance, mechanical properties, anti-aging properties, and self-healing ability, indicating that the prepared tire rubbers have good stability. In Example 4, the self-healing ability of the tire rubber decreased because an equal amount of KH-550 silane coupling agent was used instead of bis-[3-(triethoxysilyl)propyl]disulfide. In Example 5, the anti-aging properties of the tire rubber decreased due to the absence of dopamine hydrochloride, and the tensile properties also decreased slightly. In Example 6, the elongation at break of the tire rubber decreased due to the change in the mass ratio of styrene-butadiene rubber and natural rubber. In Comparative Example 1, the wear resistance, tensile strength at break, anti-aging properties, and self-healing properties of the tire rubber decreased due to the use of carbon black as an additive.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A highly stable tire rubber containing benzyltoluene, characterized in that, It includes the following raw materials by weight: 40-70 parts of composite rubber composition, 5-25 parts of plasticizer, 10-15 parts of additives, 2-5 parts of vulcanizing agent, 0.5-1.5 parts of vulcanization accelerator and 1-4 parts of stearic acid.

2. The high-stability tire rubber containing benzyltoluene according to claim 1, characterized in that, The composite rubber composition is composed of styrene-butadiene rubber and natural rubber.

3. The high-stability tire rubber containing benzyltoluene according to claim 2, characterized in that, The mass ratio of the styrene-butadiene rubber to natural rubber is 1:(1~1.3).

4. The high-stability tire rubber containing benzyltoluene according to claim 1, characterized in that, The plasticizer is polybenzyltoluene.

5. The high-stability tire rubber containing benzyltoluene according to claim 1, characterized in that, The preparation method of the auxiliary agent includes the following steps: S1. Carbon black, bis-[3-(triethoxysilyl)propyl]disulfide and 3-(trimethoxysilyl)-1-propanethiol are mixed and added to tetrahydrofuran. The mixture is heated to 55-65℃ under microwave power of 250-350W and stirred at a constant temperature for 0.5-1h. After the reaction is completed, the mixture is centrifuged, filtered, washed and dried to obtain modified carbon black. S2. Dissolve dopamine hydrochloride in Tris buffer, add copper nitrate and stir at room temperature to obtain a composite solution. Then add the modified carbon black obtained in step S1, stir vigorously for 20-30 minutes, centrifuge and filter, wash with deionized water, freeze dry to obtain the auxiliary agent.

6. The high-stability tire rubber containing benzyltoluene according to claim 5, characterized in that, In step S1, the mass of the carbon black is 5 to 8 times the total mass of bis-[3-(triethoxysilyl)propyl]disulfide and 3-(trimethoxysilyl)-1-propanethiol.

7. The high-stability tire rubber containing benzyltoluene according to claim 5, characterized in that, In step S1, the molar ratio of bis-[3-(triethoxysilyl)propyl]disulfide and 3-(trimethoxysilyl)-1-propanethiol is 1:(1~3).

8. The high-stability tire rubber containing benzyltoluene according to claim 5, characterized in that, In step S2, the mass ratio of dopamine hydrochloride to modified carbon black is 1:(1~2).

9. The high-stability tire rubber containing benzyltoluene according to claim 1, characterized in that, The vulcanizing agent is sulfur.

10. A method for preparing a highly stable tire rubber containing benzyltoluene as described in any one of claims 1 to 9, characterized in that, The process includes the following steps: the composite rubber composition and additives are put into a mixer and mixed at 150-160°C for 4-6 minutes; then plasticizer and stearic acid are added and mixed at 150-160°C for another 4-6 minutes; then vulcanizing agent and vulcanization accelerator are added and mixed at 95-105°C for 3-5 minutes to obtain high-stability tire rubber.

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