All-steel snow tire tread and preparation method therefor

Abstract

The present invention provides an all-steel snow tire tread and a preparation method therefor. The all-steel snow tire tread is prepared from the following raw materials in parts by weight: 50-80 parts of natural rubber, 20-50 parts of solution polymerized styrene-butadiene rubber having double glass transition temperatures, 40-60 parts of carbon black, 10-20 parts of white carbon black having a high specific surface area, 1-2.5 parts of a silane coupling agent, 5-10 parts of modified wet-skid resistant resin, 2-5 parts of zinc oxide, 1-3 parts of stearic acid, 1-3 parts of an anti-aging agent 4020, 1-3 parts of an anti-aging agent RD, 1-3 parts of protective wax, 1-1.8 parts of sulfur, and 1-1.5 parts of an accelerator NS. A prepared all-steel snow tread rubber has two glass transition temperatures, wherein the first glass transition temperature is smaller than or equal to -60°C, so that the all-steel snow tread rubber can be used in severely cold areas; and the second glass transition temperature is greater than or equal to -40°C and is smaller than or equal to -20°C, so that the all-steel snow tread rubber has excellent wet-skid resistance and excellent ice- and snow-covered road gripping performance, the heat generation is reduced, and the wear resistance is improved by 20% or above compared with that of existing all-steel snow tire products. Therefore, the preset invention satisfies the use requirements on the tire in the severely cold areas, and the high-performance use requirements for fuel-saving and high-wear-resistance mileage after winter or when the tire travels to non-severely cold areas across areas.

Description

All-steel snow tire tread and preparation method thereof Technical Field

[0001] The present invention relates to the technical field of all-steel snow tires, and in particular to an all-steel snow tire tread and a preparation method thereof. Background Art

[0002] With the development of the tire industry and the continuous upgrading of technology, the tire market is becoming increasingly segmented and demand is becoming more diversified. In areas with perennially low temperatures and snowy weather, the use of winter tires is gaining increasing attention from car users. Winter tires are primarily used in low temperatures and on icy and snowy roads. This requires the tire tread compound to have a lower hardness at low temperatures than conventional tires and excellent grip on ice and snow to improve the tire's maneuverability and ensure driving safety. Unlike semi-steel snow tires, all-steel snow tires carry a large load and wear quickly, and most users continue to use them after winter. Therefore, all-steel snow tires must not only have excellent resistance to wet and snowy conditions and grip on icy and snowy roads, but also excellent wear resistance and low rolling resistance to meet the high-performance requirements of long tire life and low fuel consumption.

[0003] In the prior art, when designing all-steel snow tire tread formulations, a certain amount of butadiene rubber (BR) is typically added to the natural rubber system. Butadiene rubber has a glass transition temperature (Tg) of -100°C and is the most cold-resistant synthetic rubber. This reduces the degree of hardening of the tread rubber at low temperatures and increases the contact area between the tire tread and the ground. However, BR has poor wet-skid resistance. To further improve the wet-skid resistance of the tread rubber in all-steel snow tire tread formulations, patents CN105086005B and CN105037824B use solution-polymerized styrene-butadiene rubber (SBR) with a Tg close to that of natural rubber, or oil-extended neodymium-based BR with an even lower Tg, and add highly dispersed silica, commonly used in semi-steel snow tires. The resulting tread rubber has moderate hardness, good elasticity, and excellent snow-skid resistance in severe cold and snow.

[0004] Compared with cis-1,4-butadiene rubber, the combined use of solution-polymerized styrene-butadiene rubber, whose Tg is close to that of natural rubber, can improve the tread's ice grip (tanδ@ -25℃) and wet grip (tanδ@ 0℃), but it will also increase the heat generation of the rubber compound (tanδ@ 60℃), resulting in increased tire rolling resistance; highly dispersed silica has a relatively small specific surface area and is easy to disperse in the rubber matrix, but its reinforcement of the rubber is insufficient, and the tire's wear resistance still has a lot of room for improvement. Summary of the Invention

[0005] The present invention provides an all-steel snow tire tread and a preparation method thereof, so as to solve the defects in the prior art.

[0006] On the one hand, the present invention provides an all-steel snow tire tread, which is composed of the following raw materials, in parts by weight: 50-80 parts of natural rubber, 20-50 parts of double glass transition temperature solution-polymerized styrene-butadiene rubber, 40-60 parts of carbon black, 10-20 parts of high specific surface area white carbon black, 1-2.5 parts of silane coupling agent, 5-10 parts of modified anti-skid resin, 2-5 parts of zinc oxide, 1-3 parts of stearic acid, 1-3 parts of antioxidant 4020, 1-3 parts of antioxidant RD, 1-3 parts of protective wax, 1-1.8 parts of sulfur, and 1-1.5 parts of accelerator NS.

[0007] According to the all-steel snow tire tread provided by the present invention, the dual glass transition temperature solution-polymerized styrene-butadiene rubber has a dual glass transition temperature, the first Tg of which is less than -70°C, and the second Tg temperature range is -55°C to -35°C, and the peak value of its loss factor is lower than that of ordinary low glass transition temperature solution-polymerized styrene-butadiene rubber with a single glass transition temperature.

[0008] According to the all-steel snow tire tread provided by the present invention, the carbon black is N115 or N220.

[0009] According to the all-steel snow tire tread provided by the present invention, the high specific area white carbon black has a specific surface area of ​​220-300m2 as measured by BET. 2 / g, dibutyl phthalate absorption value is 250-300cm 3 / 100g.

[0010] According to the all-steel snow tire tread provided by the present invention, the silane coupling agent is Si-75, and the weight ratio of the silane coupling agent to the high specific surface area white carbon black is 1:10-1.4:10.

[0011] According to the all-steel snow tire tread provided by the present invention, the modified moisture-resistant resin is a modified styrene and dicyclopentadiene copolymer resin.

[0012] According to the all-steel snow tire tread provided by the present invention, the preparation method of the all-steel snow tire tread is carried out according to the following steps:

[0013] (a) Natural rubber, double glass transition temperature solution polymerized styrene butadiene rubber, part of carbon black, high specific surface area white carbon black and silane coupling agent were put into an internal mixer and mixed for 40-50 seconds at a mixer speed of 40-55 rpm and a top bolt pressure of 45-55 N / cm 2 , lift the top bolt twice, hold for 5-15 seconds each time, and when the mixing temperature reaches 150-155℃, the rubber sheet is discharged to obtain a masterbatch;

[0014] (b) Place a masterbatch, the remaining carbon black, zinc oxide, stearic acid, modified anti-slip resin, antioxidant 4020, antioxidant RD, and protective wax into an internal mixer and mix for 10-30 seconds at a mixer speed of 45-50 rpm and a top bolt pressure of 45-55 N / cm 2 When the mixing temperature is 155-165℃, the rubber is discharged and the sheet is obtained to obtain the second-stage masterbatch;

[0015] (c) Add the second stage masterbatch, sulfur and accelerator NS into the internal mixer and mix for 20-30 seconds. The internal mixer speed is 20-25 rpm and the upper bolt pressure is 40-45 N / cm 2 When the mixing temperature is 100-110℃, the rubber is discharged into sheets to obtain the tread rubber.

[0016] The all-steel snow tire tread and preparation method provided by the present invention have the following technical effects: the prepared all-steel snow tire tread rubber has two glass transition temperatures, the first glass transition temperature is ≤-60°C, which meets the requirements for use in severely cold areas; the second glass transition temperature is -40°C ≤-20°C, the modulus is low at low temperatures, and the anti-skid performance and grip performance on icy and snowy roads are excellent. At the same time, heat generation is reduced and the wear resistance is improved by more than 20% compared with existing all-steel snow tire products, far reaching the ECE-R117 regulations for tire rolling resistance, snow grip index, and wet grip index, meeting the requirements for tire use in severely cold areas and the high-performance use requirements for fuel saving and high wear mileage when driving after winter or across regions to non-severely cold areas.

[0017] 1. Using solution-polymerized styrene-butadiene rubber (SBR) with dual glass transition temperatures (Tg), the first Tg of the SBR is less than -70°C, and the second Tg temperature range is -55°C to -35°C. The peak value of the loss factor is lower than that of the ordinary low-Tg SBR with a single glass transition temperature. This makes the all-steel snow tread rubber have two glass transition temperatures, moderate hardness at low temperatures, low elastic modulus at -25°C, high loss factor tanδ value at 0°C, and low loss factor tanδ value at 60°C, taking into account high ice and snow grip, anti-skid performance and low heat generation performance.

[0018] 2. Using high-specific-area silica with a BET specific surface area of ​​220-300m2 / g and a dibutyl phthalate absorption value of 250-300cm3 / 100g, by adjusting the components and optimizing the ratio with the silane coupling agent Si75, the tire can penetrate water films to ensure grip on wet, icy and snowy grounds. At the same time, the wear resistance is significantly improved compared to tread compounds using low-specific-surface-area, highly dispersed silica, and is close to that of tread compounds filled with pure carbon black.

[0019] 3. The use of modified styrene and dicyclopentadiene copolymer resin, which has excellent compatibility with rubber, improves the tread's wet-skid resistance while also reducing rolling resistance. While maintaining the all-steel snow tire's superior grip on ice and snow, rolling resistance is further reduced and wear resistance is significantly improved. This greatly meets the safety needs of truck and bus users in low-temperature, snowy areas, as well as the high-performance requirements of low fuel consumption and high wear resistance for post-winter travel or cross-region travel to less cold areas.

[0020] The present invention uses double glass transition temperature solution-polymerized styrene-butadiene rubber, high specific area white carbon black, modified styrene and dicyclopentadiene copolymer resin and optimizes the ratio of each component, so that the all-steel tread rubber prepared by mixing and producing has a low elastic modulus at low temperatures, strong grip on ice, snow and wetlands, and low rolling resistance; the wear resistance is improved by more than 20%, meeting the use of tires in severely cold areas and the demand for fuel saving and high mileage when users do not replace snow tires after winter or when driving to non-severely cold areas; and solves the current problems of insufficient reinforcement of tire tread rubber and the need to improve the wear resistance of tires. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] FIG1 is a DMA temperature scanning curve of the tread rubber prepared in Comparative Example 1 and Example 4 of the present invention. DETAILED DESCRIPTION

[0023] The specific embodiments of the present invention are described in further detail below in conjunction with the examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention.

[0024] In order to better understand the purpose of the present invention, the present invention is described in further detail below.

[0025] An all-steel snow tire tread according to an embodiment of the present application is composed of the following raw materials, in parts by weight: 50-80 parts of natural rubber, 20-50 parts of double glass transition temperature solution-polymerized styrene-butadiene rubber, 40-60 parts of carbon black, 10-20 parts of high specific surface area white carbon black, 1-2.5 parts of silane coupling agent, 5-10 parts of modified anti-skid resin, 2-5 parts of zinc oxide, 1-3 parts of stearic acid, 1-3 parts of antioxidant 4020, 1-3 parts of antioxidant RD, 1-3 parts of protective wax, 1-1.8 parts of sulfur, and 1-1.5 parts of accelerator NS.

[0026] To further optimize the above technical solution, the double glass transition temperature solution-polymerized styrene-butadiene rubber has a double glass transition temperature, the first Tg of which is less than -70°C, and the second Tg temperature range is -55°C to -35°C, and the peak value of its loss factor is lower than that of the ordinary low glass transition temperature solution-polymerized styrene-butadiene rubber with a single glass transition temperature.

[0027] To further optimize the above technical solution, the carbon black is N115 or N220.

[0028] In order to further optimize the above technical solution, the specific surface area of ​​high specific area white carbon black is 220-300m 2 / g, dibutyl phthalate absorption value is 250-300cm 3 / 100g.

[0029] To further optimize the above technical solution, the silane coupling agent is Si-75, and the weight ratio of the silane coupling agent to the high specific surface area white carbon black is 1:10-1.4:10.

[0030] In order to further optimize the above technical solution, the modified moisture-resistant resin is a modified styrene and dicyclopentadiene copolymer resin.

[0031] To further optimize the above technical solution, the preparation method of the all-steel snow tire tread is carried out according to the following steps:

[0032] (a) 70 parts of natural rubber, 30 parts of double glass transition temperature solution polymerized styrene-butadiene rubber, part of carbon black, high specific surface area white carbon black and silane coupling agent were put into an internal mixer and mixed for 40-50 seconds at a mixer speed of 40-55 rpm and a top bolt pressure of 45-55 N / cm 2 , lift the top bolt twice, hold for 5-15 seconds each time, and when the mixing temperature reaches 150-155℃, the rubber sheet is discharged to obtain a masterbatch;

[0033] (b) Place a masterbatch, the remaining carbon black, zinc oxide, stearic acid, modified anti-slip resin, antioxidant 4020, antioxidant RD, and protective wax into an internal mixer and mix for 10-30 seconds at a mixer speed of 45-50 rpm and a top bolt pressure of 45-55 N / cm2 When the mixing temperature is 155-165℃, the rubber is discharged and the sheet is obtained to obtain the second-stage masterbatch;

[0034] (c) Add the second stage masterbatch, sulfur and accelerator NS into the internal mixer and mix for 20-30 seconds. The internal mixer speed is 20-25 rpm and the upper bolt pressure is 40-45 N / cm 2 When the mixing temperature is 100-110℃, the rubber is discharged into sheets to obtain the tread rubber. Example 1

[0035] 70 parts of natural rubber, 30 parts of double glass transition temperature solution-polymerized styrene-butadiene rubber, 25 parts of carbon black, 15 parts of highly dispersed white carbon black, and 1.2 parts of silane coupling agent were put into an internal mixer and mixed for 45 seconds. The internal mixer speed was 50 rpm and the upper bolt pressure was 50 N / cm 2 , lift the top bolt twice, hold for 10 seconds each time, and when the mixing temperature reaches 150℃, discharge the rubber and get a masterbatch;

[0036] Put a masterbatch, 25 parts of carbon black, 3 parts of zinc oxide, 2 parts of stearic acid, 5 parts of anti-slip resin, 1.5 parts of antioxidant 4020, 1.5 parts of antioxidant RD, and 1.5 parts of protective wax into an internal mixer and mix for 20 seconds. The internal mixer speed is 45 rpm and the upper bolt pressure is 50 N / cm 2 When the mixing temperature is 155-165℃, the rubber is discharged and the sheet is obtained to obtain the second-stage masterbatch;

[0037] Put the second stage masterbatch, 1.5 parts of sulfur and 1.3 parts of accelerator NS into the internal mixer and mix for 25 seconds. The internal mixer speed is 22 rpm and the upper bolt pressure is 42 N / cm 2 When the mixing temperature is 105℃, the rubber is discharged into sheets to obtain the tread rubber. Example 2

[0038] 70 parts of natural rubber, 30 parts of double glass transition temperature solution-polymerized styrene-butadiene rubber, 25 parts of carbon black, 15 parts of high specific surface area white carbon black and 1.5 parts of silane coupling agent were put into an internal mixer and mixed for 45 seconds at a mixer speed of 50 rpm and a top bolt pressure of 50 N / cm. 2 , lift the top bolt twice, hold for 10 seconds each time, and when the mixing temperature reaches 150℃, discharge the rubber and get a masterbatch;

[0039] Put a masterbatch, 25 parts of carbon black, 3 parts of zinc oxide, 2 parts of stearic acid, 5 parts of anti-slip resin, 1.5 parts of antioxidant 4020, 1.5 parts of antioxidant RD, and 1.5 parts of protective wax into an internal mixer and mix for 20 seconds. The internal mixer speed is 45 rpm and the upper bolt pressure is 50 N / cm 2 When the mixing temperature reaches 160℃, the rubber is discharged and the sheet is obtained to obtain the second-stage masterbatch;

[0040] Put the second stage masterbatch, 1.5 parts of sulfur and 1.4 parts of accelerator NS into the internal mixer and mix for 25 seconds. The internal mixer speed is 23 rpm and the upper bolt pressure is 42 N / cm 2 When the mixing temperature is 105℃, the rubber is discharged into sheets to obtain the tread rubber. Example 3

[0041] 70 parts of natural rubber, 30 parts of double glass transition temperature solution-polymerized styrene-butadiene rubber, 25 parts of carbon black, 15 parts of high specific surface area white carbon black and 1.5 parts of silane coupling agent were put into an internal mixer and mixed for 45 seconds at a mixer speed of 50 rpm and a top bolt pressure of 50 N / cm. 2 , lift the top bolt twice, hold for 10 seconds each time, and when the mixing temperature reaches 150℃, discharge the rubber and get a masterbatch;

[0042] Put a masterbatch, 25 parts of carbon black, 3 parts of zinc oxide, 2 parts of stearic acid, 5 parts of modified anti-slip resin, 1.5 parts of antioxidant 4020, 1.5 parts of antioxidant RD, and 1.5 parts of protective wax into an internal mixer and mix for 20 seconds. The internal mixer speed is 45 rpm and the upper bolt pressure is 50 N / cm 2 When the mixing temperature is 160℃, the rubber is discharged and the sheet is obtained to obtain the second-stage masterbatch;

[0043] Put the second stage masterbatch, 1.5 parts of sulfur and 1.4 parts of accelerator NS into the internal mixer and mix for 25 seconds. The internal mixer speed is 22 rpm and the upper bolt pressure is 42 N / cm 2 When the mixing temperature is 105℃, the rubber is discharged into sheets to obtain the tread rubber. Example 4

[0044] 60 parts of natural rubber, 40 parts of double glass transition temperature solution-polymerized styrene-butadiene rubber, 23 parts of carbon black, 20 parts of high specific surface area white carbon black and 2.4 parts of silane coupling agent were put into an internal mixer and mixed for 45 seconds at a mixer speed of 50 rpm and a top bolt pressure of 50 N / cm. 2 , lift the top bolt twice, hold for 10 seconds each time, and when the mixing temperature reaches 150℃, discharge the rubber and get a masterbatch;

[0045] Put a masterbatch, 23 parts of carbon black, 3 parts of zinc oxide, 2 parts of stearic acid, 8 parts of modified anti-slip resin, 1.5 parts of antioxidant 4020, 1.5 parts of antioxidant RD, and 1.5 parts of protective wax into an internal mixer and mix for 10-30 seconds. The internal mixer speed is 45 rpm and the upper bolt pressure is 50 N / cm 2 When the mixing temperature is 160℃, the rubber is discharged and the sheet is obtained to obtain the second-stage masterbatch;

[0046] Put the second stage masterbatch, 1.4 parts of sulfur and 1.5 parts of accelerator NS into the internal mixer and mix for 25 seconds. The internal mixer speed is 22 rpm and the upper bolt pressure is 42 N / cm 2When the mixing temperature is 105℃, the rubber is discharged into sheets to obtain the tread rubber. Example 5

[0047] 50 parts of natural rubber, 50 parts of double glass transition temperature solution polymerized styrene-butadiene rubber, 21 parts of carbon black, 20 parts of high specific surface area white carbon black and 2.4 parts of silane coupling agent were put into an internal mixer and mixed for 45 seconds. The internal mixer speed was 50 rpm and the upper bolt pressure was 50 N / cm 2 , lift the top bolt twice, hold for 10 seconds each time, and when the mixing temperature reaches 150℃, discharge the rubber and get a masterbatch;

[0048] Put a masterbatch, 21 parts of carbon black, 3 parts of zinc oxide, 2 parts of stearic acid, 10 parts of modified anti-slip resin, 1.5 parts of antioxidant 4020, 1.5 parts of antioxidant RD, and 1.5 parts of protective wax into an internal mixer and mix for 20 seconds. The internal mixer speed is 45 rpm and the upper bolt pressure is 50 N / cm 2 When the mixing temperature reaches 160℃, the rubber is discharged and the sheet is obtained to obtain the second-stage masterbatch;

[0049] Put the second stage masterbatch, 1.4 parts of sulfur and 1.5 parts of accelerator NS into the internal mixer and mix for 25 seconds. The internal mixer speed is 22 rpm and the upper bolt pressure is 42 N / cm 2 When the mixing temperature is 105℃, the rubber is discharged into sheets to obtain the tread rubber.

[0050] Comparative Example 1

[0051] 70 parts of natural rubber, 30 parts of low glass transition temperature solution polymerized styrene-butadiene rubber, 25 parts of carbon black, 15 parts of highly dispersed silica and 1.2 parts of silane coupling agent were put into an internal mixer and mixed for 45 seconds. The internal mixer speed was 50 rpm and the upper bolt pressure was 50 N / cm 2 , lift the top bolt twice, hold for 10 seconds each time, and when the mixing temperature reaches 150℃, discharge the rubber and get a masterbatch;

[0052] Put a masterbatch, 25 parts of carbon black, 3 parts of zinc oxide, 2 parts of stearic acid, 5 parts of anti-slip resin, 1.5 parts of antioxidant 4020, 1.5 parts of antioxidant RD, and 1.5 parts of protective wax into an internal mixer and mix for 20 seconds. The internal mixer speed is 45 rpm and the upper bolt pressure is 50 N / cm 2 When the mixing temperature reaches 160℃, the rubber is discharged and the sheet is obtained to obtain the second-stage masterbatch;

[0053] Put the second stage masterbatch, 1.5 parts of sulfur and 1.3 parts of accelerator NS into the internal mixer and mix for 25 seconds. The internal mixer speed is 22 rpm and the upper bolt pressure is 42 N / cm 2 When the mixing temperature is 105℃, the rubber is discharged into sheets to obtain the tread rubber.

[0054] Table 1 Comparative Example 1, composition of Examples 1-5

[0055]

[0056] The tread rubber, as specified in Table 1, was prepared in a BR Banbury internal mixer using three separate mixing stages: two non-productive mixing stages and one productive mixing stage. The two non-productive mixing stages were completed with mixing lasting approximately 2-3 minutes, until the rubber temperature reached 150-155°C and 155-165°C, respectively. The productive mixing stage was completed with mixing lasting approximately 1-1.5 minutes, until the rubber temperature reached 100-110°C.

[0057] Table 2 Mechanical and physical properties of Comparative Example 1 and Examples 1-5

[0058]

[0059] Table 2 lists the physical and mechanical properties of the comparative examples and examples. All properties of the rubber compounds were tested in accordance with national or industry standards, with the vulcanization conditions being 151°C for 30 min. Dynamic mechanical properties were characterized by temperature sweeps of the vulcanized rubber using a dynamic viscoelastic spectrum analyzer (DMA) manufactured by GABO, Germany. The test conditions were compression mode, 10 Hz frequency, 5% static strain, 0.2% dynamic strain, a temperature range of -70°C to 70°C, and a heating rate of 2°C / min.

[0060] Usually, the elastic modulus E' at -25℃ is used to characterize the grip on ice and snow. The lower the value, the lower the modulus and the better the grip on ice and snow. The tanδ at 0℃ is used to characterize the anti-skid performance. The higher the value, the stronger the anti-skid performance. The tanδ at 60℃ is used to characterize the heat generation performance of the rubber. The lower the value, the lower the heat generation of the rubber, that is, the lower the rolling resistance of the tire.

[0061] As can be seen from Table 2 and Figure 1, solution-polymerized styrene-butadiene rubber with a low peak double glass transition temperature Tg can adjust the Tg and DMA curve peak shape of the tread rubber, lower the Tg of the tread rubber, increase tanδ at -25℃ and 0℃, reduce E' at -25℃, and reduce tanδ at 60℃, thereby improving the tread rubber's ice and snow grip and anti-wet skid performance, reducing heat generation and improving wear resistance; high-specific area silica can pierce the water film, provide anti-wet skid performance, enhance the reinforcement performance of the rubber, and significantly improve the wear resistance compared to highly dispersed silica; modified styrene and dicyclopentadiene copolymer resin can improve anti-wet skid performance and reduce rolling resistance.

[0062] Table 3 Performance test data of 12R22.5 specification all-steel snow tires produced with tread rubber of Comparative Example 1 and Examples 3-44

[0063]

[0064] Table 3 shows the performance test data for 12R22.5 all-steel snow tires produced using the tread rubbers of Comparative Example 1 and Examples 3-4. Tire rolling resistance was tested at the National Engineering Laboratory, snow performance was tested at the Heilongjiang Red River Valley Automotive Testing Center according to ECE-R117 regulations, and tire wear performance was tested in accordance with GB / T 29041-2012.

[0065] As can be seen from Table 3, the all-steel snow tires produced with the tread rubbers prepared in Examples 3 and 4 have obvious advantages in rolling resistance, wet performance, snow performance, wear resistance, etc., and can achieve the optimal balance of various performance indicators of the tread rubber.

[0066] In summary, the present invention uses dual-glass transition temperature solution-polymerized styrene-butadiene rubber, high-area silica, modified styrene and dicyclopentadiene copolymer resin and optimizes the ratio of each component. The all-steel tread rubber prepared by mixing and producing has two glass transition temperatures, the first glass transition temperature is ≤-60°C, which meets the requirements for use in extremely cold areas; the second glass transition temperature is -40°C ≤-20°C, the elastic modulus is low at low temperatures, the grip on ice and snow and wetlands is strong, and the rolling resistance is low, far exceeding the ECE-R117 regulations for tire rolling resistance and snow grip index and wetland grip index requirements; the wear resistance is improved by more than 20%, which meets the requirements for use of tires in extremely cold areas, and the fuel-saving and high mileage requirements of users who do not replace snow tires after the cold winter or when driving to non-cold areas.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A tread of an all-steel snow tire, characterized in that, It consists of the following raw materials in parts by weight: 50 - 80 parts of natural rubber, 20 - 50 parts of solution-polymerized styrene-butadiene rubber with a dual glass transition temperature, 40 - 60 parts of carbon black, 10 - 20 parts of white carbon black with a high specific surface area, 1 - 2.5 parts of silane coupling agent, 5 - 10 parts of modified anti-wet skid resin, 2 - 5 parts of zinc oxide, 1 - 3 parts of stearic acid, 1 - 3 parts of antioxidant 4020, 1 - 3 parts of antioxidant RD, 1 - 3 parts of protective wax, 1 - 1.8 parts of sulfur, and 1 - 1.5 parts of accelerator NS.

2. The tread of the all-steel snow tire according to claim 1, wherein The solution-polymerized styrene-butadiene rubber with a dual glass transition temperature has a dual glass transition temperature, where the first Tg is less than -70 °C, the second Tg ranges from -55 °C to -35 °C, and the peak value of its loss factor is lower than that of ordinary solution-polymerized styrene-butadiene rubber with a single low glass transition temperature.

3. The tread of an all-steel snow tire according to claim 1, characterized in that, The carbon black is N115 or N220.

4. The tread of the all-steel snow tire according to claim 1, characterized in that, The specific surface area of the high specific surface area precipitated silica is measured by BET to be 220 - 300 m 2 / g, and the dibutyl phthalate absorption value is 250 - 300 cm 3 / 100 g.

5. The tread of an all-steel snow tire according to claim 1, characterized in that, The silane coupling agent is Si-75, and the weight ratio of it to the white carbon black with a high specific surface area is 1:10 - 1.4:

10.

6. The tread of the all-steel snow tire according to claim 1, wherein The modified anti-wet resin is a copolymer resin of modified styrene and dicyclopentadiene.

7. The tread of the all-steel snow tire according to claim 1, characterized in that, The preparation method of the tread of the all-steel snow tire is carried out according to the following steps: (a) Put natural rubber, solution-polymerized styrene-butadiene rubber with double glass transition temperatures, part of carbon black, white carbon black with high specific surface area, and silane coupling agent into an internal mixer and knead for 40 - 50 s. The rotational speed of the internal mixer is 40 - 55 rpm, and the pressure of the upper ram is 45 - 55 N / cm 2 , lift the upper ram twice, each time for 5 - 15 s, and discharge the rubber and take out the sheet when the kneading temperature is 150 - 155 °C to obtain the first-stage masterbatch; (b) Put a section of masterbatch and the remaining carbon black, zinc oxide, stearic acid, modified anti-wet skid resin, antioxidant 4020, antioxidant RD, and protective wax into a mixer and knead for 10 - 30 s. The mixer speed is 45 - 50 rpm, and the upper plug pressure is 45 - 55 N / cm 2 , and discharge the rubber and take out the sheet when the kneading temperature is 155 - 165 °C to obtain the second-stage masterbatch; (c) Put the two-stage masterbatch, sulfur, and accelerator NS into the internal mixer and knead for 20 - 30 s. The rotational speed of the internal mixer is 20 - 25 rpm, and the pressure of the upper plug is 40 - 45 N / cm 2 , and discharge the rubber and sheet out when the kneading temperature is 100 - 110 °C to obtain the tread rubber.

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