A high-slip resistance, low-noise electric vehicle tire and its preparation method

Abstract

The present invention provides a highly slip-resistant, low-noise electric vehicle tire and a method for preparing the same, relating to the technical field of tire preparation. The highly slip-resistant, low-noise electric vehicle tire of the present invention comprises a tread made from a rubber composition; the rubber composition comprises a rubber component and a filler; the filler is prepared by cross-linking carbon black and carbon nanotubes using 4-hydroxybutyl acrylate glycidyl ether, an unsaturated acid anhydride, and cardanol. By controlling the tread rubber formulation and tire structure, the resulting tire exhibits excellent mechanical properties, high slip resistance, and noise reduction.

Description

Technical Field

[0001] The present invention relates to the technical field of tire preparation, and in particular to a highly anti-slip and low-noise tire for electric vehicles and a preparation method thereof. Background Art

[0002] At present, cars have become an indispensable means of transportation in people's lives. With the development of the automobile industry, people have put forward higher requirements for the handling safety, fuel efficiency and comfort of tires during driving, such as handling safety, low energy consumption, comfort, etc. Therefore, clear performance requirements have been formulated for tires' wet grip, rolling resistance and noise.

[0003] Cars generate noise when driving at high speeds, and tire noise is particularly prominent, affecting the driver's driving experience. Therefore, people desire low-noise tires. However, ensuring vehicle safety is crucial, which requires maintaining the overall operational stability of the tire.

[0004] Research progress has been made to address these issues. For example, the use of solution-polymerized styrene-butadiene rubber improves wet grip performance, while composite polyisoprene rubber further balances wet grip performance. Another example is the placement of polyurethane foam, produced by varying the blowing agent content, within the inner cavity of a pneumatic tire, which reduces resonant noise within the tire while also improving durability.

[0005] However, the above method has only been used to improve the noise or anti-skid performance of the tire. Therefore, how to achieve both low noise and high anti-skid performance of the tire remains a problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a highly anti-slip and low-noise electric vehicle tire and a preparation method thereof.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A highly anti-slip and low-noise electric vehicle tire, comprising a tread formed from a rubber composition; wherein:

[0009] The rubber composition comprises a rubber component and a filler;

[0010] The filler is prepared by hybrid cross-linking and modifying carbon black and carbon nanotubes with 4-hydroxybutyl acrylate glycidyl ether, unsaturated acid anhydride and cardanol.

[0011] In a further embodiment, the rubber component is selected from any one or more of natural rubber, solution-polymerized styrene-butadiene rubber, and butadiene rubber; preferably, it is a combination of natural rubber and solution-polymerized styrene-butadiene rubber, and the mass ratio of the two is (50-60):(40-50).

[0012] In a further embodiment, the mass ratio of carbon black to carbon nanotubes in the filler is (5-7.5):(2.5-5), and the preferred mass ratio is 7.2:2.8.

[0013] In a further embodiment, the particle size of the carbon black is 100 nm to 600 nm.

[0014] In a more preferred embodiment, the carbon black has a particle size of 400 nm.

[0015] In a further embodiment, the carbon nanotubes are multi-walled carbon nanotubes, and the outer diameter of the carbon nanotubes is 10 to 30 nm and the length is 5 to 15 μm.

[0016] In a further embodiment, the amount of 4-hydroxybutyl acrylate glycidyl ether in the filler is 5-8% of the total mass of the carbon black and the carbon nanotubes, preferably 6% of the total mass of the carbon black and the carbon nanotubes.

[0017] In a further embodiment, the unsaturated acid anhydride in the filler is selected from any one or more of acrylic anhydride, itaconic anhydride, and maleic anhydride, preferably maleic anhydride; the amount of the unsaturated acid anhydride is 15-20% of the total mass of the carbon black and the carbon nanotubes, preferably 16% of the total mass of the carbon black and the carbon nanotubes.

[0018] In a further embodiment, the amount of cardanol in the filler is 5-10% of the total mass of the carbon black and the carbon nanotubes, preferably 7% of the total mass of the carbon black and the carbon nanotubes.

[0019] In a further embodiment, the filler is prepared by the following method:

[0020] (1) Treating carbon nanotubes and carbon black with concentrated sulfuric acid respectively;

[0021] (2) Mixing cardanol and unsaturated acid anhydride, adding sulfuric acid as a catalyst, reacting at 200-210°C for 2-3 hours, cooling to 70-80°C, adding 4-hydroxybutyl acrylate glycidyl ether and reacting for 24-48 hours to obtain a copolymer solution;

[0022] (3) The copolymer solution is mixed with the carbon black and carbon nanotubes pretreated in step (1), ultrasonically treated, an initiator is added, and the mixture is reacted at 150-155° C. for 1-2 hours to obtain the filler.

[0023] Preferably, in step (1), the treatment step is: respectively placing carbon nanotubes and carbon black into a sulfuric acid solution with a mass fraction of 5 to 20%, ultrasonically treating them for 30 to 60 minutes, and then taking them out and drying them after the treatment.

[0024] Preferably, in step (2), the amount of sulfuric acid used is 0.5-5% of the total mass of the reactants.

[0025] Preferably, in step (3), the initiator is selected from azo initiators and peroxide initiators; the amount of the initiator added is 0.5 to 3% of the total mass of the reactants.

[0026] In a further embodiment, the rubber composition further comprises any one or more of stearic acid, zinc oxide, an antioxidant, a vulcanizing agent, and an accelerator.

[0027] Preferably, the antioxidant is selected from any one or more of antioxidant DNP, antioxidant 4020, antioxidant TMQ, and antioxidant BLE.

[0028] Preferably, the accelerator is selected from any one or more of dithiocarbamate accelerators, aldehydeamine accelerators, thiuram accelerators, sulfenamide accelerators, thiazole accelerators and xanthate accelerators.

[0029] Preferably, the vulcanizing agent is sulfur.

[0030] The rubber composition comprises the following raw materials in parts by weight: 100 parts of rubber component, 40-60 parts of filler, 1-5 parts of stearic acid, 2-6 parts of zinc oxide, 1-5 parts of antioxidant, 1-3 parts of vulcanizing agent, and 2-5 parts of accelerator.

[0031] Preferably, the rubber composition comprises the following raw materials in parts by weight: 100 parts of rubber component, 55 parts of filler, 2 parts of stearic acid, 4 parts of zinc oxide, 3.5 parts of antioxidant, 2.5 parts of vulcanizing agent, and 3 parts of accelerator.

[0032] In a further embodiment, the highly anti-skid and low-noise electric vehicle tire further comprises a carcass, a sidewall, a belt layer and a bead.

[0033] Preferably, the belt layer is provided between the tread and the carcass, and the material of the belt layer is steel cord.

[0034] Preferably, the carcass is made of aramid fiber and / or nylon fiber.

[0035] Further preferably, the surface of the steel cords in the belt layer is further coated with rubber, and the mass of the rubber is 0.1 to 5% of the steel cords.

[0036] The rubber material comprises the following raw materials in percentage by weight: 100 parts of natural rubber, 5-15 parts of polyurethane resin, 40-55 parts of carbon black, 2-5 parts of basalt fiber, 3-8 parts of sulfur, 0.5-2 parts of accelerator, 1-5 parts of antioxidant, and 0.5-1.5 parts of cobalt boroacylate.

[0037] On the other hand, the method for preparing the above-mentioned high anti-slip and low-noise electric vehicle tire comprises the following steps:

[0038] The rubber composition is kneaded to obtain a rubber mix, which is then pressurized and vulcanized at 160-180° C. to obtain a vulcanized rubber. The vulcanized rubber is made into a tread to prepare a lightweight, high-strength and low rolling resistance tire for new energy vehicles.

[0039] In a further embodiment, the rubber composition mixing step comprises:

[0040] The materials except the vulcanizing agent and the accelerator are mixed at 140-150° C. for 3-5 minutes, and then the vulcanizing agent and the accelerator are added and mixed at 130-145° C. for 1-2 minutes to obtain a mixed rubber.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The high-wet-skid resistance and low-noise electric vehicle tire of the present invention optimizes the formula of the tread rubber so that the obtained tire has excellent mechanical properties, high wet-skid resistance and noise reduction performance.

[0043] 2. Compared with the traditional tread rubber using carbon black as reinforcing filler, the tread rubber of the present invention uses a filler obtained by hybrid cross-linking and modifying carbon black and carbon nanotubes with 4-hydroxybutyl acrylate glycidyl ether, unsaturated acid anhydride and cardanol instead. The compatibility of the modified carbon black and carbon nanotubes with the rubber component is improved, and the components work together to make the resulting tire have excellent mechanical properties, high wet skid resistance and noise reduction performance.

[0044] 3. Carbon nanotubes are added to the filler of the present invention to replace part of the carbon black. The combination of carbon nanotubes and carbon black helps to improve the strength of the tire and enhance the noise reduction performance.

[0045] 4. The filler of the present invention is modified with 4-hydroxybutyl acrylate glycidyl ether, unsaturated acid anhydride and cardanol. The modifier forms a cross-linked structure on the surface. On the one hand, it increases the dispersibility in the rubber component, thereby exerting the reinforcing effect of carbon black and carbon nanotubes. On the other hand, the three modifiers form a multi-cross-linked structure after modifying the filler, which helps to enhance the tire's ability to absorb and isolate noise, has excellent noise reduction performance, and can increase wet skid resistance. In particular, when the ratio of the three modifiers is limited, it can ensure that the rubber composition can fully exert its strength and toughness, improve mechanical properties, and further ensure that the noise reduction of the tire is more lasting, with the noise maintained below 60dB.

[0046] 5. The present invention has the characteristics of simple operation, strong safety, strong practicality and suitability for popularization and use. DETAILED DESCRIPTION

[0047] The following non-limiting examples are provided to enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. The following is merely an illustrative description of the scope of the present invention, and those skilled in the art may make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present invention.

[0048] The present invention is further described below by way of specific examples. Unless otherwise specified, the various chemical reagents used in the examples of the present invention were obtained through conventional commercial channels.

[0049] Examples 1 to 4

[0050] A rubber composition, the specific components of which are shown in Table 1 below, in parts by weight.

[0051] Table 1

[0052]

[0053] The filler was prepared by the following method (the specific raw material amounts are shown in Table 2 below, in parts by weight):

[0054] (1) Place carbon nanotubes and carbon black in a 10% sulfuric acid solution, ultrasonically treat for 30 minutes, and then take out and dry them;

[0055] (2) Cardanol and unsaturated anhydride were mixed, sulfuric acid (0.1% of the total mass of the reactants) was added as a catalyst, the mixture was reacted at 200°C for 3 h, cooled to 70°C, 4-hydroxybutyl acrylate glycidyl ether was added and the mixture was reacted for 48 h to obtain a copolymer solution;

[0056] (3) The carbon black and carbon nanotubes pretreated in step (1) are added to the copolymer solution of step (2), ultrasonically treated, and 0.5% of the weight of the reaction raw materials, azobisisobutyronitrile, are added, and reacted at 150° C. for 2 h. After removal, the filler is washed and dried to obtain the filler.

[0057] Table 2

[0058]

[0059] This embodiment also provides a method for preparing the rubber composition, comprising the following steps:

[0060] Natural rubber, solution polymerized styrene-butadiene rubber and filler are mixed and kneaded at 140°C for 3 minutes; then mixed with stearic acid, zinc oxide, antioxidant and anti-scorch agent and kneaded at 130°C for 2 minutes; then sulfur and accelerator are added and kneaded at 120°C for 120 seconds to obtain a rubber compound.

[0061] Examples 5 to 8

[0062] This embodiment is basically the same as embodiment 2, except that the ratio of carbon black to carbon nanotubes and the ratio of modifier in the filler preparation process are different. The specific amounts of raw materials used are shown in Table 3 below (by weight).

[0063] Table 3

[0064]

[0065] Comparative Examples 1 to 4

[0066] This comparative example is basically the same as Example 2, except that the raw materials used in the filler preparation process are different (in parts by weight), as shown in Table 4 below.

[0067] Table 4

[0068]

[0069] Comparative Example 5

[0070] This comparative example is basically the same as Example 2, except that the filler in this comparative example is replaced by an equal amount of carbon black.

[0071] Test Example 1

[0072] The rubber mixtures obtained in the above examples and comparative examples were vulcanized at 161° C. for 20 min using a flat vulcanizer to obtain sulfur rubber, which was then subjected to the following tests:

[0073] 1. Mechanical properties test: tensile properties test is carried out in accordance with standard GB / T528-2009.

[0074] 2. Vibration Characteristics Index: The sulfur rubber composition was cut into predetermined sizes and the loss coefficient (η) was measured at 23°C using a central vibration exciter from B&K. The loss coefficient of Comparative Example 5 was set to 100. The Vibration Characteristics Index (η) was expressed as the percentage of the loss coefficients of the remaining groups relative to Comparative Example 5. A higher η indicates better road noise reduction performance.

[0075] 3. Dynamic analysis test (DMA): Test conditions are: tensile mode; frequency, 12 Hz; static strain 7%, dynamic strain 0.25%; temperature rise, 2°C / min.

[0076] The test results are shown in Table 5 below.

[0077] Table 5

[0078]

[0079] As shown in the table, the rubber composition prepared by the formula and preparation method defined by the present invention has a tensile strength of more than 23 MPa and an elongation at break of more than 500%, with excellent tensile properties. Compared with Example 2, the tensile strength and elongation of Comparative Examples 1 to 5 decreased significantly, and the tensile properties deteriorated. From the results of the vibration characteristic index, compared with Comparative Example 5, the vibration characteristic index of the rubber compositions of Comparative Examples 1 to 4 increased, and the noise reduction performance improved. It can be seen that compared with carbon black, the use of the filler provided by the present invention helps to improve the noise reduction performance of the material; the vibration characteristic index of the rubber composition of the embodiment reached more than 120, and the highest was 128, with excellent noise reduction performance. From the dynamic analysis test data, compared with Comparative Example 5, the tanδ@60℃ data of the rubber compositions of Comparative Examples 1 to 4 decreased, and the tanδ@0℃ data increased, and the anti-wet skid ability was improved. This shows that compared with carbon black, the use of the filler provided by the present invention helps to improve the anti-wet skid performance of the material; the rubber composition of the embodiment has a low tanδ@60℃ value and a high tanδ@0℃ value, and excellent anti-wet skid ability.

[0080] Example 13

[0081] Tires were made from the vulcanized rubbers prepared in Examples 1-8 and Comparative Examples 1-5, and their performance was evaluated. The tire specifications were 225 / 55R17 97W. The tires were numbered as follows: tires prepared using Examples 1-8 were designated as tires #1-8, and tires prepared using Comparative Examples 1-5 were designated as tires #9-13.

[0082] Example 14

[0083] The difference from Example 13 is that the surface of the steel cord of the belt layer is coated with 0.5% rubber, which contains 100 parts of natural rubber, 5 parts of polyurethane resin, 5 parts of basalt fiber, 55 parts of carbon black, 3 parts of sulfur, 0.5 parts of thiazole vulcanization accelerator MBTS, 1 part of antioxidant DNP, and 0.5 parts of cobalt borate; a tire of the same specifications was made and recorded as tire 14#.

[0084] A tire without adding basalt fiber to the rubber compound used in the belt layer was used as a comparison, and the resulting tire was recorded as tire 15#.

[0085] Test Example 2

[0086] The noise reduction performance of the above tires was tested according to GB / T32789-2016 "Tire Noise Test Method - Drum Method"; after 48 hours of drum rotation under the same conditions, the noise test was repeated after 12 hours of rest.

[0087] The test results are shown in Table 7 below.

[0088] Table 7

[0089]

[0090] As shown in the table, the tires prepared using the formula and preparation method defined in the present invention have a noise level of 60dB or less, with low noise levels, excellent noise reduction performance, and stable and long-lasting performance. Tires 9 to 13# are noisier than Tire 2#, and their noise reduction performance is significantly lower than Tire 2#. Tire 14#'s initial noise level is comparable to that of Example 2, but after 48 hours, its noise level is lower than that of Example 2. Tire 15#, which uses a different rubber compound for the belt layer than Tire 14#, has a significantly lower noise reduction performance than Tire 14#. This may be because the addition of basalt fiber to the rubber compound creates a tiny pore structure that helps increase noise absorption. Furthermore, the material's microporous structure is stable, allowing it to maintain long-lasting noise reduction performance.

[0091] The above description of the embodiments is intended to facilitate understanding and application of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A high-slip resistance, low-noise electric vehicle tire, characterized in that: comprising a tread made of a rubber composition; wherein, The rubber composition comprises a rubber component and a filler; The filler is prepared by hybrid cross-linking and modifying carbon black and carbon nanotubes with 4-hydroxybutyl acrylate glycidyl ether, unsaturated acid anhydride and cardanol; The rubber component is selected from any one or more combinations of natural rubber, solution-polymerized styrene-butadiene rubber, and butadiene rubber; The filler is specifically prepared by the following method: (1) Treating carbon nanotubes and carbon black with concentrated sulfuric acid respectively; the mass ratio of carbon black to carbon nanotubes is (5-7.5):(2.5-5); (2) Mixing cardanol and unsaturated acid anhydride, adding sulfuric acid as a catalyst, reacting at 200-210°C for 2-3 hours, cooling to 70-80°C, adding 4-hydroxybutyl acrylate glycidyl ether and reacting for 24-48 hours to obtain a copolymer solution; (3) The copolymer solution is mixed with the carbon black and carbon nanotubes pretreated in step (1), ultrasonically treated, an initiator is added, and the mixture is reacted at 150-155° C. for 1-2 hours to obtain the filler.

2. The high-slip and low-noise electric vehicle tire according to claim 1, characterized in that: The rubber component is a combination of natural rubber and solution-polymerized styrene-butadiene rubber in a mass ratio of (50-60):(40-50).

3. The electric vehicle tire with high wet skid resistance and low noise according to claim 1, characterized in that: The mass ratio of carbon black to carbon nanotubes is 7.2:2.

8.

4. The electric vehicle tire with high wet skid resistance and low noise according to claim 1, characterized in that: The unsaturated acid anhydride is selected from any one or more of acrylic anhydride, itaconic anhydride and maleic anhydride.

5. The electric vehicle tire with high wet skid resistance and low noise according to claim 4, characterized in that: The unsaturated acid anhydride is maleic anhydride.

6. The electric vehicle tire with high wet skid resistance and low noise according to claim 1, characterized in that: The amount of 4-hydroxybutyl acrylate glycidyl ether in the filler is 5 to 8% of the total mass of carbon black and carbon nanotubes; The amount of the unsaturated anhydride is 15-20% of the total mass of the carbon black and the carbon nanotubes; The amount of cardanol used is 5-10% of the total mass of carbon black and carbon nanotubes.

7. The electric vehicle tire with high wet skid resistance and low noise according to claim 6, characterized in that: The amount of 4-hydroxybutyl acrylate glycidyl ether in the filler is 6% of the total mass of carbon black and carbon nanotubes.

8. The electric vehicle tire with high wet skid resistance and low noise according to claim 6, characterized in that: The amount of the unsaturated anhydride used is 16% of the total mass of the carbon black and the carbon nanotubes.

9. The electric vehicle tire with high wet skid resistance and low noise according to claim 6, characterized in that: The amount of cardanol used is 7% of the total mass of carbon black and carbon nanotubes.

10. The electric vehicle tire with high wet skid resistance and low noise according to claim 1, characterized in that: The rubber composition further comprises any one or more of stearic acid, zinc oxide, an antioxidant, a vulcanizing agent, and an accelerator.

11. The electric vehicle tire with high wet skid resistance and low noise according to claim 10, characterized in that: The rubber composition comprises the following raw materials in parts by weight: 100 parts of rubber component, 40-60 parts of filler, 1-5 parts of stearic acid, 2-6 parts of zinc oxide, 1-5 parts of antioxidant, 1-3 parts of vulcanizing agent, and 2-5 parts of accelerator.

12. The electric vehicle tire with high wet skid resistance and low noise according to claim 1, characterized in that: The highly anti-slip and low-noise electric vehicle tire also includes a carcass, a sidewall, a belt layer and a bead; the belt layer is arranged between the tread and the carcass, and the material of the belt layer is steel cord.

13. The method for preparing a high-wet-skid-resistant and low-noise electric vehicle tire according to any one of claims 1 to 12, characterized in that: The following steps are involved: The rubber composition is kneaded to obtain a rubber mix, which is then pressurized and vulcanized at 160-180° C. to obtain a vulcanized rubber. The vulcanized rubber is made into a tread to prepare a lightweight, high-strength and low rolling resistance tire for new energy vehicles.

14. The method for preparing a high-slip resistance and low-noise electric vehicle tire according to claim 13, characterized in that: The rubber composition mixing step comprises: The materials except the vulcanizing agent and the accelerator are mixed at 140-150° C. for 3-5 minutes, and then the vulcanizing agent and the accelerator are added and mixed at 130-145° C. for 1-2 minutes to obtain a mixed rubber.

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