Snow tire tread rubber composition and preparation method thereof

Abstract

The present invention provides a snow tire tread rubber composition and its preparation method, belonging to the technical field of tire rubber compositions. It can solve the problem of high rolling resistance values ​​in existing snow tire tread rubber. The snow tire tread rubber composition is composed, by weight, of 100 parts of a base rubber and 100-200 parts of auxiliary ingredients. The base rubber includes 10-50 parts of butadiene-vinyl rubber, 10-20 parts of high-vinyl polybutadiene rubber, and 30-80 parts of solution-polymerized styrene-butadiene rubber. The auxiliary ingredients include 60-100 parts of highly dispersed silica, 1-5 parts of carbon black, 2-10 parts of amino silicone oil, 2-10 parts of silane coupling agent, 30-50 parts of heavy naphthenic oil, 3-7 parts of an activator, 3-6 parts of an antioxidant, 1-3 parts of ordinary sulfur, and 1-4 parts of an accelerator. When applied to snow tires, the tread rubber composition can significantly improve the tire's grip on ice, snow, and slippery roads, ensuring driving safety while also reducing the tire's rolling resistance and fuel efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of tire rubber compositions, and in particular relates to a snow tire tread rubber composition and a preparation method thereof. Background Art

[0002] Winter tires are designed for driving on ice, snow, and slippery surfaces during the harsh winter weather and extremely low outdoor temperatures. To enhance grip and ensure driving safety, winter tires typically utilize a special rubber compound, a wider tread, and deep, wide grooves. However, this also results in higher rolling resistance. However, tire rolling resistance significantly impacts a vehicle's fuel efficiency, with the tread compound contributing approximately 49% of this resistance. Therefore, reducing the tread compound's rolling resistance is crucial for reducing the overall rolling resistance of the tire. Furthermore, with tire manufacturers prioritizing energy conservation, emission reduction, and low-carbon environmental protection, as well as consumer demand for higher-performance tires, reducing rolling resistance and improving fuel economy while ensuring driving safety has become a new trend.

[0003] Chinese invention patent CN107602962A discloses a formula for a tread rubber for a snow tire with an anti-slip property and a preparation method thereof. By adding modified slag powder and nano-titanium carbide, the tread rubber's ability to destroy water film on wet and slippery roads is improved, thereby improving the anti-slip performance. Chinese invention patent CN106046459A discloses a formula for a tread rubber for a snow tire with an anti-slip property and a preparation method thereof. By adjusting the amount of components such as solution-polymerized styrene-butadiene rubber, natural rubber, butadiene rubber, environmentally friendly aromatic oil, and accelerator, the tread hardness is reduced and the anti-slip performance of the tread rubber is improved.

[0004] In the above-mentioned patent disclosure, although the anti-skid performance of the snow tread rubber is improved, the importance of low rolling resistance is ignored. Summary of the Invention

[0005] In response to the above-mentioned technical problems existing in the prior art, the present invention proposes a snow tire tread rubber composition and a preparation method thereof. The obtained tread rubber composition has low tread hardness, low hysteresis loss, and excellent anti-skid performance. When used in snow tires, it can significantly improve the grip performance of automobile tires on ice, snow, and wet roads, ensuring driving safety, while reducing the rolling resistance of the tires and reducing fuel efficiency.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a snow tire tread rubber composition, which is composed of 100 parts of base rubber and 100-200 parts of auxiliary components in parts by weight, wherein the base rubber includes 10-50 parts of butadiene-butadiene rubber, 10-20 parts of high vinyl polybutadiene rubber, and 30-80 parts of solution-polymerized styrene-butadiene rubber; the auxiliary components include 60-100 parts of highly dispersed silica, 1-5 parts of carbon black, 2-10 parts of amino silicone oil, 2-10 parts of silane coupling agent, 30-50 parts of heavy cyclohexane oil, 3-7 parts of activator, 3-6 parts of antioxidant, 1-3 parts of ordinary sulfur, and 1-4 parts of accelerator.

[0007] As a preferred embodiment, the butadiene-pentadiene rubber is a high cis-1,4-butadiene-isoprene copolymer rubber with a number average molecular weight of (10-30)×10 4 g / mol, wherein the butadiene structural unit and the isoprene structural unit are randomly arranged, and the isoprene content accounts for 10% to 30% (molar content).

[0008] Preferably, the mass fraction of 1,2-structure (vinyl group) in the high vinyl polybutadiene rubber is greater than 65%.

[0009] As a preferred solution polymerized styrene butadiene rubber is a single-end modified silicon-coupled butadiene-styrene copolymer rubber with a number average molecular weight of (30-60)×10 4 , weight average molecular weight is (40~80)×10 4 , wherein the styrene content is 10% to 20% and the total vinyl content is 10% to 40%.

[0010] Preferably, the nitrogen adsorption specific surface area of ​​highly dispersed silica is 100 to 160 m 2 / g.

[0011] As a preference, the carbon black iodine absorption value is 90-130 g / kg, and the DBP value is (100-120)×10 -5 m 3 / kg, and the tinting strength is 110% to 130%.

[0012] Preferably, the amino silicone oil is a low-viscosity, low-molecular-weight silicone oil with an amino value of 0.1 to 0.5 and a terminal group being a long-chain alkyl group.

[0013] Preferably, the active agent includes 2 to 5 parts of zinc oxide and 1 to 3 parts of stearic acid; the antioxidant includes 2 to 4 parts of antioxidant 6PPD, 1 to 3 parts of antioxidant RD, and 1 to 3 parts of low-temperature protective wax; and the accelerator includes 1 to 3 parts of accelerator CZ and 1 to 3 parts of accelerator DPG.

[0014] The present invention also provides a method for preparing the above-mentioned snow tire tread rubber composition, comprising the following steps:

[0015] Masterbatch mixing: add butylene-pentadiene rubber, high vinyl polybutadiene rubber, solution polymerized styrene-butadiene rubber, highly dispersed white carbon black, carbon black, amino silicone oil, and silane coupling agent to the upper internal mixer of the series internal mixer, press the bolt for 15 to 40 seconds, the mixer speed is 40 to 50 rpm, and the upper bolt pressure is maintained at 0.4 to 0.6 MPa. The activator and antioxidant are added after the bolt is lifted, and the mixture is mixed to 120° C.; heavy naphthenic oil is added after the bolt is lifted, the bolt is pressed and mixed for 20 to 40 seconds, and the mixer speed is 35 to 45 rpm; the upper bolt pressure is maintained at 0.4 to 0.6 MPa, the bolt is lifted, the bolt is pressed, and the mixture is mixed to 140 to 150° C. and the temperature is kept constant for 60 to 100 seconds, and the rubber is discharged to the lower internal mixer of the series internal mixer, and the mixture is mixed at a constant temperature of 130 to 150° C. for 40 to 100 seconds. The rubber is discharged and the lower sheet is cooled to obtain the masterbatch;

[0016] Final rubber mixing: Add a set amount of masterbatch, accelerator, and ordinary sulfur into the internal mixer and mix for 40 seconds. The internal mixer speed is 20-30 rpm. Maintain the upper plug pressure at 0.4-0.6 MPa. After lifting the plug, press the plug for 80 seconds. After lifting the plug again, press the plug and mix for 110 seconds. Discharge the rubber and cool the sheet to obtain the final rubber mix.

[0017] Compared with the prior art, the advantages and positive effects of the present invention are:

[0018] (1) The snow tire tread rubber composition of the present invention has low hardness, low hysteresis loss, and high anti-skid performance. In existing formulas, the base rubber is usually a combination of natural rubber and high cis-butadiene rubber. However, natural rubber and high cis-butadiene rubber are not completely compatible. There is a phase interface in the rubber composition, and there is also a difference in the amount of bonding rubber formed with white carbon black between natural rubber and high cis-butadiene rubber. The snow tire tread rubber composition of the present invention uses butadiene-isoprene rubber to replace traditional natural rubber and high cis-butadiene rubber, which indirectly promotes the dispersion of white carbon black. Butadiene-isoprene rubber is a high cis-1,4-butadiene-isoprene copolymer rubber. The high content of cis-1,4-butadiene structure makes the rubber composition have a modulus at low temperature. The molecular chain is softer, and due to the random copolymerization of butadiene structure and isoprene, the rubber macromolecular chain will not crystallize at low temperatures, and the activity of the molecular chain is increased; high vinyl polybutadiene rubber introduces abundant vinyl side groups, which can improve the anti-skid performance of the snow tire tread rubber composition; the solution-polymerized styrene-butadiene rubber has low styrene and vinyl contents, and has undergone single-end modification and silicon coupling, which reduces the free ends while being beneficial to chemical bonding with silica, enhancing the dispersibility of silica, thereby reducing the hysteresis loss of the snow tire tread rubber composition and improving the anti-skid performance of the snow tire tread rubber composition.

[0019] (2) The auxiliary component of the snow tire tread rubber composition of the present invention adopts highly dispersed silica. Medium and low specific surface area silica has better dispersibility than high specific surface area silica, and has a higher filling ratio under the condition of the same hardness. The surface of the snow tire tread rubber composition has relatively more exposed silica particles. During the wear process of the silica-filled tread rubber composition, the rubber surface is worn away, and the silica particles are exposed. Under wet road conditions, the water film can be effectively punctured to improve the anti-skid performance. The auxiliary component also introduces amino silicone oil for non-rubber industries. Since the molecular chain of amino silicone oil is an easily twisted spiral structure, the energy required for the rotation of the silicon-oxygen bond on the main chain is almost zero, and it can rotate 360 ​​degrees. The main chain is very flexible. The long-chain alkane on one end of the molecular chain is hydrophobic and can be compatible with the hydrophobic rubber macromolecule, while the strong polar amino group on the other end can form hydrogen bonds with the hydroxyl group on the surface of silica. At the same time, due to the presence of silicon element, according to the principle of like dissolves like, the amino silicone oil has a stronger effect on the surface of silica, thereby promoting the dispersion of silica. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0021] The present invention provides a snow tire tread rubber composition and a preparation method thereof. The composition uses butadiene-vinyl butadiene rubber (BPV) to replace the combination of natural rubber and high-cis-butadiene rubber (NR). Aminosilicone oil used in non-rubber industries is introduced as an auxiliary component of the composition. The resulting rubber composition is applied to winter tires and exhibits low tread hardness, low hysteresis loss, and high wet skid resistance. The present invention comprises, by weight, 100 parts of a base rubber and 100-200 parts of auxiliary components. The base rubber comprises 10-50 parts of butadiene-vinyl butadiene rubber (BPV), 10-20 parts of high-vinyl polybutadiene rubber (HPV), and 30-80 parts of solution-polymerized styrene-butadiene rubber (SBR). The auxiliary components comprise 60-100 parts of highly dispersed silica, 1-5 parts of carbon black, 2-10 parts of aminosilicone oil, 2-10 parts of a silane coupling agent, 30-50 parts of heavy naphthenic oil, 3-7 parts of an activator, 3-6 parts of an antioxidant, 1-3 parts of ordinary sulfur, and 1-4 parts of an accelerator. Among them, butadiene-pentadiene rubber is a high cis-1,4-butadiene-isoprene copolymer rubber with a number average molecular weight of (10-30)×10 4g / mol, wherein the butadiene structural unit and the isoprene structural unit are randomly arranged, and the isoprene content accounts for 10% to 30% (molar content). The molecular structure of the above-mentioned butadiene-pentadiene rubber contains cis-1,4-butadiene structure and isoprene structure, which is used to replace the use of natural rubber and cis-1,4-butadiene rubber, and the hysteresis loss of the obtained tread rubber composition is lower than when natural rubber, cis-1,4-butadiene rubber or natural rubber and cis-1,4-butadiene rubber are used alone or in combination; the cis-1,4-butadiene structure and the isoprene structure are randomly arranged, so that the rubber composition will not be affected by crystallization at low temperatures and its performance will not be affected. A certain isoprene structure content ensures that the basic physical properties of the rubber composition are not affected. The mass fraction of 1,2-structure (vinyl) in high vinyl polybutadiene rubber is greater than 65%, and the rich vinyl side groups can improve the anti-skid performance of the rubber composition. Solution-polymerized styrene butadiene rubber is a single-end modified silicon-coupled butadiene-styrene copolymer rubber with a number average molecular weight of (30 to 60)×10 4 , weight average molecular weight is (40~80)×10 4 The styrene content is 10% to 20% and the total vinyl content is 10% to 40%. The solution-polymerized styrene-butadiene rubber has a glass transition temperature between -50°C and -70°C, resulting in excellent low-temperature performance for the rubber composition. Terminal modification and silicon coupling enhance the bonding between the rubber macromolecules and silica, ensuring the mechanical properties of the rubber composition.

[0022] Among the auxiliary components used in the snow tire tread rubber composition of the embodiment of the present invention, the nitrogen adsorption specific surface area of ​​the highly dispersed silica is 100 to 160 m 2 / g, high fraction of white carbon black is beneficial to improve the anti-skid performance of the rubber composition. The carbon black iodine absorption value is 90-130g / kg, and the DBP value is (100-120)×10 -5 m 3 / kg, with a tinting strength of 110% to 130%. Auxiliary ingredients also include amino silicone oil for use in non-rubber industries. Amino silicone oil is a low-viscosity, low-molecular-weight silicone oil with an amino value between 0.1 and 0.5 and a long-chain alkyl end group. The amino silicone oil can enhance interaction with silica and promote its dispersion. Among other auxiliary ingredients, the silane coupling agent is preferably TESPD; the activator includes 2 to 5 parts of zinc oxide and 1 to 3 parts of stearic acid; the antioxidant includes chemical antioxidants and physical antioxidants, among which the chemical antioxidant includes 2 to 4 parts of 6PPD and 1 to 3 parts of RD, and the physical antioxidant includes 1 to 3 parts of low-temperature protective wax; the accelerator includes 1 to 3 parts of CZ and 1 to 3 parts of DPG.

[0023] The method for preparing the snow tire tread rubber composition of the present invention comprises the following steps:

[0024] Masterbatch mixing: add butylene-pentadiene rubber, high vinyl polybutadiene rubber, solution polymerized styrene-butadiene rubber, highly dispersed white carbon black, carbon black, amino silicone oil, and silane coupling agent to the upper internal mixer of the series internal mixer, press the bolt for 15 to 40 seconds, the mixer speed is 40 to 50 rpm, and the upper bolt pressure is maintained at 0.4 to 0.6 MPa. The activator and antioxidant are added after the bolt is lifted, and the mixture is mixed to 120° C.; heavy naphthenic oil is added after the bolt is lifted, the bolt is pressed and mixed for 20 to 40 seconds, and the mixer speed is 35 to 45 rpm; the upper bolt pressure is maintained at 0.4 to 0.6 MPa, the bolt is lifted, the bolt is pressed, and the mixture is mixed to 140 to 150° C. and the temperature is kept constant for 60 to 100 seconds, and the rubber is discharged to the lower internal mixer of the series internal mixer, and the mixture is mixed at a constant temperature of 130 to 150° C. for 40 to 100 seconds. The rubber is discharged and the lower sheet is cooled to obtain the masterbatch;

[0025] Final rubber mixing: Add a set amount of masterbatch, accelerator, and ordinary sulfur into the internal mixer and mix for 40 seconds. The internal mixer speed is 20-30 rpm. Maintain the upper plug pressure at 0.4-0.6 MPa. After lifting the plug, press the plug for 80 seconds. After lifting the plug again, press the plug and mix for 110 seconds. Discharge the rubber and cool the sheet to obtain the final rubber mix.

[0026] In order to more clearly and in detail introduce the snow tire tread rubber composition and the preparation method thereof provided by the embodiments of the present invention, they will be described below in conjunction with specific embodiments.

[0027] Example 1

[0028] The formula of the snow tire tread rubber composition of this embodiment is shown in Table 1, and the mixing preparation is carried out according to the following steps:

[0029] Masterbatch mixing: add butylene-pentadiene rubber, high vinyl polybutadiene rubber, solution polymerized styrene-butadiene rubber, highly dispersed white carbon black, carbon black, amino silicone oil, and silane coupling agent TESPD to the upper mixer of the series internal mixer, press the plug for 35 seconds, the mixer speed is 50 rpm, and the upper push plug pressure is maintained at 0.5 MPa. Then, the activator zinc oxide and stearic acid, antioxidant 6PPD, RD, and low-temperature protective wax are added after the plug is pulled out, and the mixture is mixed to 120°C; then, heavy naphthenic oil is added after the plug is pulled out, and the plug is pressed and mixed for 35 seconds, the mixer speed is 45 rpm; then, the upper push plug pressure is maintained at 0.5 MPa, and the plug is pulled out and pressed, and the mixture is mixed to 147°C and kept at a constant temperature for 60 seconds. Then, the rubber is discharged to the lower mixer of the series internal mixer, and the mixture is mixed at a constant temperature of 143°C for 100 seconds. After the rubber is discharged, the lower sheet is cooled to obtain the masterbatch;

[0030] Final rubber mixing: Add appropriate amount of masterbatch, accelerators CZ and DPG, and ordinary sulfur into the internal mixer and mix for 40 seconds. The internal mixer speed is 26 rpm. Maintain the upper plug pressure at 0.5 MPa. After lifting the plug, press the plug for 80 seconds. After lifting the plug again, press the plug and mix for 110 seconds. Discharge the rubber and cool the sheet to obtain the final rubber mix.

[0031] Example 2

[0032] The formula of the snow tire tread rubber composition of this embodiment is shown in Table 1, and the mixing preparation method is the same as that of Example 1.

[0033] Table 1: Formulation of rubber composition for snow tire tread of Example 1-2

[0034] raw materials Example 1 Example 2 NBR 30 40 High vinyl polybutadiene rubber 20 10 Solution-polymerized styrene-butadiene rubber 50 50 Highly dispersed silica 80 80 carbon black 5 5 amino silicone oil 4 4 Silane coupling agent TESPD 6.4 6.4 Heavy naphthenic oil 38 38 Active agent zinc oxide 3 3 Active agent stearic acid 2 2 Antioxidant 6PPD 2.5 2.5 Antioxidant RD 1.5 1.5 Low temperature protective wax 1.5 1.5 Accelerator CZ 1.6 1.6 Accelerator DPG 2.0 2.0 Ordinary sulfur 1.2 1.2 total 248.7 248.7

[0035] Comparative Example 1

[0036] The formula of the tread rubber composition of this comparative example is shown in Table 2, and the mixing preparation was carried out according to the following steps:

[0037] Masterbatch mixing: natural rubber, high cis-butadiene rubber, high vinyl polybutadiene rubber, solution polymerized styrene-butadiene rubber, highly dispersed silica, carbon black, silica dispersant, and silane coupling agent TESPD were added to the upper mixer of the series internal mixer, the plug was pressed for 35 seconds, the mixer speed was 50 rpm, and the upper push plug pressure was maintained at 0.5 MPa. The activator zinc oxide and stearic acid, antioxidant 6PPD, RD, and low-temperature protective wax were added after the plug was pulled out, and the mixture was mixed to 120°C; heavy naphthenic oil was added after the plug was pulled out, the plug was pressed and mixed for 35 seconds, and the mixer speed was 45 rpm; the upper push plug pressure was maintained at 0.5 MPa, the plug was pulled out, the plug was pressed, and the mixture was mixed to 147°C and kept at a constant temperature for 60 seconds, and the rubber was discharged to the lower mixer of the series internal mixer, and the mixture was mixed at a constant temperature of 143°C for 100 seconds. The rubber was discharged and the lower sheet was cooled to obtain the masterbatch;

[0038] Final rubber mixing: Add the set amount of masterbatch, accelerators CZ and DPG, and ordinary sulfur into the internal mixer and mix for 40 seconds. The internal mixer speed is 26 rpm. Maintain the upper plug pressure at 0.5 MPa. After lifting the plug, press the plug for 80 seconds. After lifting the plug again, press the plug and mix for 110 seconds. Discharge the rubber and cool the sheet to obtain the final rubber mix.

[0039] Comparative Example 2

[0040] The formula of the tread rubber composition of this comparative example is shown in Table 2, and the mixing preparation was carried out according to the following steps:

[0041] Masterbatch mixing: natural rubber, high cis-butadiene rubber, high vinyl polybutadiene rubber, solution polymerized styrene-butadiene rubber, highly dispersed white carbon black, carbon black, amino silicone oil, silane coupling agent TESPD were added to the upper mixer of the series internal mixer, the plug was pressed for 35 seconds, the mixer speed was 50 rpm, and the upper plug pressure was maintained at 0.5 MPa. The activator zinc oxide and stearic acid, antioxidant 6PPD, RD and low-temperature protective wax were added after the plug was pulled out, and the mixture was mixed to 120°C; heavy naphthenic oil was added after the plug was pulled out, the plug was pressed and mixed for 35 seconds, and the mixer speed was 45 rpm; the upper plug pressure was maintained at 0.5 MPa, the plug was pulled out, the plug was pressed and mixed to 147°C and the temperature was kept constant for 60 seconds, the rubber was discharged to the lower mixer of the series internal mixer, and the mixture was mixed at a constant temperature of 143°C for 100 seconds. The rubber was discharged and the lower sheet was cooled to obtain the masterbatch;

[0042] Final rubber mixing: Add the set amount of masterbatch, accelerators CZ and DPG, and ordinary sulfur into the internal mixer, mix for 40 seconds, rotate the internal mixer at 26 rpm, maintain the upper plug pressure at 0.5 MPa, lift the plug and press the plug for 80 seconds, lift the plug again and press the plug and mix for 110 seconds, discharge the rubber and cool the sheet to obtain the final rubber mix.

[0043] Comparative Example 3

[0044] The formula of the tread rubber composition of this comparative example is shown in Table 2. The preparation method is the same as that of Comparative Example 2. Specifically, the tread rubber composition of Comparative Example 3 is prepared by mixing according to the following steps:

[0045] Masterbatch mixing: natural rubber, high cis-butadiene rubber, high vinyl polybutadiene rubber, solution polymerized styrene-butadiene rubber, highly dispersed white carbon black, carbon black, amino silicone oil, silane coupling agent TESPD were added to the upper mixer of the series internal mixer, the plug was pressed for 35 seconds, the mixer speed was 50 rpm, and the upper plug pressure was maintained at 0.5 MPa. The activator zinc oxide and stearic acid, antioxidant 6PPD, RD and low-temperature protective wax were added after the plug was pulled out, and the mixture was mixed to 120°C; heavy naphthenic oil was added after the plug was pulled out, the plug was pressed and mixed for 35 seconds, and the mixer speed was 45 rpm; the upper plug pressure was maintained at 0.5 MPa, the plug was pulled out, the plug was pressed and mixed to 147°C and the temperature was kept constant for 60 seconds, the rubber was discharged to the lower mixer of the series internal mixer, and the mixture was mixed at a constant temperature of 143°C for 100 seconds. The rubber was discharged and the lower sheet was cooled to obtain the masterbatch;

[0046] Final rubber mixing: Add the set amount of masterbatch, accelerators CZ and DPG, and ordinary sulfur into the internal mixer, mix for 40 seconds, rotate the internal mixer at 26 rpm, maintain the upper plug pressure at 0.5 MPa, lift the plug and press the plug for 80 seconds, lift the plug again and press the plug and mix for 110 seconds, discharge the rubber and cool the sheet to obtain the final rubber mix.

[0047] Table 2 Comparative Examples 1-3 Tread Rubber Composition Formula

[0048]

[0049] Performance Testing

[0050] The performance of the vulcanized rubber materials obtained in Examples 1-2 and Comparative Examples 1-2 was tested, and the test results are shown in Table 3 below.

[0051] Table 3 Performance test data of the rubber materials obtained from Examples 1-2 and Comparative Examples 1-3

[0052]

[0053] The data in Table 3 show that compared to Comparative Example 1, Comparative Example 2 uses aminosilicone oil instead of silica dispersant, resulting in improved tensile properties. The strain sweep ΔG of the vulcanized rubber reflects filler-filler interactions; lower values ​​indicate less filler-filler interactions, i.e., better silica dispersion. The significantly lower ΔG in Comparative Example 2 indicates that aminosilicone oil significantly promotes silica dispersion. Comparative Example 2 exhibits better silica dispersion and a sufficient silanization reaction, resulting in favorable changes in DMA data such as E'@-20°C, tanδ@0°C, and tanδ@70°C. Compared to Comparative Example 2, Comparative Example 3 increases the amount of high-cis butadiene rubber. While the basic physical properties of the vulcanized rubber remain comparable, changes in the raw rubber matrix primarily contribute to changes in dynamic mechanical properties.

[0054] Comparative Examples 1 and 2 correspond to Example 1. Compared with Example 1, Comparative Example 1 replaces the butyl-elastomer rubber with natural rubber and high-cis-butyl rubber, and replaces the aminosilicone oil with a silica dispersant; compared with Example 1, Comparative Example 2 replaces the butyl-elastomer rubber with natural rubber and high-cis-butyl rubber. According to the performance test data in Table 3, the Shore A hardness of the vulcanizates obtained from Example 1 and Comparative Examples 1-2 is comparable, both ranging from 52 to 55. While the basic physical properties are comparable, Example 1 has a better tensile strength than both Comparative Examples 1 and 2. This is because the use of butyl-elastomer rubber reduces the phase interface, indirectly promoting silica dispersion and strengthening the intermolecular forces of the vulcanizate. Furthermore, the strain sweep ΔG of the vulcanizate from Example 1 is significantly reduced, confirming the aforementioned effect of the butyl-elastomer rubber. From the DMA test results, the Tg of the vulcanizates of Example 1 and Comparative Examples 1-2 are all between -50 and -45°C, and the vulcanizates have excellent cold resistance. The Tg point of the rubber composition of Example 1 is lower, and E'@-20°C is significantly reduced. This is because the isoprene structure and butadiene structure in the molecular chain of the butadiene-vinyl rubber are randomly arranged, and the activity of the molecular chain will not be reduced due to crystallization at low temperatures. Therefore, the Tg point is lowered and the low-temperature modulus is reduced, that is, the low-temperature performance of the rubber composition is better; compared with Comparative Examples 1 and 2, the tanδ@0°C of Example 1 is significantly increased, indicating better anti-skid performance; compared with Comparative Examples 1 and 2, the tanδ@70°C of Example 1 is significantly decreased, indicating that the hysteresis loss of the vulcanizate is lower and the tire rolling resistance is low. This is because after using butadiene-vinyl rubber to replace natural rubber and butadiene rubber, the activity of the vulcanizate composition is enhanced at lower temperatures, and the vulcanizate phases are evenly dispersed, the chemical bonding force with white carbon black is strong, and the internal friction heat generation is reduced.

[0055] Comparative Example 3 corresponds to Example 2. Comparative Example 3 replaces the butadiene-vinyl rubber with natural rubber and high-cis-butadiene rubber. Compared with Comparative Example 3, the Shore A hardness of the vulcanized rubber after replacing the butadiene-vinyl rubber is equivalent to that of the vulcanized rubber in Example 2, ranging from 52 to 55; the basic physical properties are equivalent, and the tensile strength of Example 2 is better; the strain sweep △G' of the vulcanized rubber in Example 2 is also significantly reduced. From the DMA test results, the Tg of the vulcanized rubbers in Example 2 and Comparative Example 3 are both between -50 and -45°C. The Tg point of the rubber composition in Example 2 is lower, and E'@-20°C is significantly reduced. Moreover, compared with Example 1, Example 2 increases the amount of butadiene-vinyl rubber, and the E'@-20°C value is lower; the tanδ@0°C of Example 2 is significantly increased, indicating that the anti-skid performance is better, and the tanδ@70°C is significantly reduced, indicating that the vulcanized rubber has lower hysteresis loss and low tire rolling resistance.

[0056] In summary, the present invention introduces butadiene-pentadiene rubber, uses high-vinyl polybutadiene rubber, single-end silicon-coupled solution-polymerized styrene-butadiene rubber, uses a high proportion of highly dispersed silica and amino silicone oil, and the resulting rubber composition has lower hardness, high anti-skid performance and lower rolling resistance.

[0057] The above-described embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, modifications, evolutions, and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A snow tire tread rubber composition, characterized in that: In parts by weight, it is composed of 100 parts of base rubber and 100-200 parts of auxiliary components, wherein the base rubber includes 10-50 parts of butadiene-pentadiene rubber, 10-20 parts of high vinyl polybutadiene rubber, and 30-80 parts of solution-polymerized styrene-butadiene rubber; the auxiliary components include 60-100 parts of highly dispersed white carbon black, 1-5 parts of carbon black, 2-10 parts of amino silicone oil, 2-10 parts of silane coupling agent, 30-50 parts of heavy cyclohexane oil, 3-7 parts of activator, 3-6 parts of antioxidant, 1-3 parts of ordinary sulfur, and 1-4 parts of accelerator; wherein the butadiene-pentadiene rubber is a high cis-1,4-butadiene-isoprene copolymer rubber, and the solution-polymerized styrene-butadiene rubber is a single-end modified silicon-coupled butadiene-styrene copolymer rubber.

2. The snow tire tread rubber composition according to claim 1, characterized in that: The number average molecular weight of high cis-1,4-butadiene-isoprene copolymer rubber is (10~30)×10 4 g / mol, wherein the butadiene structural units and the isoprene structural units are randomly arranged, and the molar content of isoprene accounts for 10%~30%.

3. The snow tire tread rubber composition according to claim 1, characterized in that: The mass fraction of 1,2-structure vinyl in high vinyl polybutadiene rubber is greater than 65%.

4. The snow tire tread rubber composition according to claim 1, wherein The number average molecular weight of the single-end modified silicon-coupled butadiene-styrene copolymer rubber is (30~60)×10 4 , weight average molecular weight is (40~80)×10 4 , among which the styrene content is 10%~20% and the total vinyl content is 10%~40%.

5. The snow tire tread rubber composition according to claim 1, wherein: The nitrogen adsorption specific surface area of ​​highly dispersed silica is 100~160m 2 / g.

6. The snow tire tread rubber composition according to claim 1, wherein: The iodine absorption value of carbon black is 90~130g / kg, and the DBP value is (100~120)×10 -5 m 3 / kg, and the tinting strength is 110%~130%.

7. The snow tire tread rubber composition according to claim 1, characterized in that: Amino silicone oil is a low-viscosity, low-molecular-weight silicone oil with an amino value of 0.1~0.5 and a long-chain alkyl end group.

8. The snow tire tread rubber composition according to claim 1, wherein: The active agent includes 2-5 parts of zinc oxide and 1-3 parts of stearic acid; the antioxidant includes 2-4 parts of antioxidant 6PPD, 1-3 parts of antioxidant RD, and 1-3 parts of low-temperature protective wax; the accelerator includes 1-3 parts of accelerator CZ and 1-3 parts of accelerator DPG.

9. The method for preparing the snow tire tread rubber composition according to any one of claims 1 to 8, characterized in that: The following steps are involved: Masterbatch mixing: add butylene-pentadiene rubber, high vinyl polybutadiene rubber, solution polymerized styrene-butadiene rubber, highly dispersed white carbon black, carbon black, amino silicone oil, and silane coupling agent to the upper mixer of the series internal mixer, press the plug for 15-40 seconds, the mixer speed is 40-50 rpm, and the upper plug pressure is maintained at 0.4-0.6 MPa. Then, the plug is pulled out to add the activator and antioxidant, and the mixture is mixed to 120°C; then, the plug is pulled out to add the heavy naphthenic oil, the plug is pressed and mixed for 20-40 seconds, the mixer speed is 35-45 rpm; then, the upper plug pressure is maintained at 0.4-0.6 MPa, the plug is pulled out and pressed, and the mixture is mixed to 140-150°C and kept at a constant temperature for 60-100 seconds, and the rubber is discharged to the lower mixer of the series internal mixer, and the mixture is mixed at a constant temperature of 130-150°C for 40-100 seconds. After the rubber is discharged, the lower sheet is cooled to obtain the masterbatch; Final rubber mixing: Add the set amount of masterbatch, accelerator and ordinary sulfur into the internal mixer and mix for 40 seconds. The internal mixer speed is 20-30 rpm. Maintain the upper plug pressure at 0.4-0.6 MPa. After lifting the plug, press the plug for 80 seconds. After lifting the plug again, press the plug and mix for 110 seconds. Discharge the rubber and cool the sheet to obtain the final rubber mix.

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