Tread rubber composition, tread rubber and tire for low-temperature ice surface

Abstract

The invention provides a tread rubber composition, tread rubber and a tire for a low-temperature ice surface. The tread rubber composition comprises 30-70 parts of natural rubber, 10-40 parts of butadiene rubber, 15-30 parts of modified trioctyl phosphate, 5-20 parts of nano diene, 40-60 parts of white carbon black, 2-4 parts of zinc oxide, 3-10 parts of a silane coupling agent, 1-2 parts of stearic acid, 1-2 parts of sulfur, 1-3 parts of an accelerant and 3-10 parts of an anti-aging agent. By optimizing the formula and selecting the materials, the road holding force and the wear resistance of the obtained tread rubber composition under the low-temperature ice surface condition are remarkably improved. Particularly, due to the introduction of the modified trioctyl phosphate, the low-temperature performance and the wet skid resistance of the rubber are enhanced, and due to the use of the nano diene, the mechanical strength and the cold resistance of the material are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tires, and in particular to a tread rubber composition, a tread rubber and a tire for low-temperature ice surfaces. Background Art

[0002] Driving safety has always been highly valued, and the contact between tires and the ground plays an important role in safe driving. The special climate and ground conditions in winter often cause the tire's grip to drop significantly, especially in high-latitude regions and countries where the winter temperature is extremely low and the road is covered with ice and snow all year round, and safety accidents caused by car skidding often occur.

[0003] In order to improve the safety of automobile driving in winter, it is necessary to develop more winter tire tread rubber formulas with high ice grip performance to fill some gaps in this field. Some researchers have noticed that improving the cold resistance of tread rubber can well improve the friction between winter tires and ice surfaces. For example, CN114891286A discloses a high-grip and high-cold-resistant tread rubber and its preparation method, which uses natural rubber with better comprehensive performance, and neodymium-based butadiene rubber with good low-temperature resistance, and uses high-styrene-based styrene-butadiene rubber with good grip, brominated butyl rubber 3745 and brominated butyl reclaimed rubber to reduce the glass transition temperature of the tread rubber (-40°C), and improve the low-temperature elasticity of the tread rubber. At the same time, improving the surface roughness of the tread rubber can also increase the friction with the ice surface and improve the ice grip performance. CN115975267A discloses an ice tire tread rubber composition and its preparation method, innovatively adding quartz powder to improve the ability of the rubber to puncture the water film, greatly improving the ice grip performance of the tread rubber. However, the above two methods either improve the cold resistance of the tread rubber or improve its ice grip, but it is difficult to take both properties into account and obtain a tread rubber that has both high cold resistance and high ice grip and can meet the requirements of application in extremely cold conditions.

[0004] Based on this, how to provide a tread rubber composition that has both high cold resistance and high ice grip performance so that it can meet the application requirements under extremely cold and freezing conditions is one of the important technical problems that need to be solved in this field. Summary of the invention

[0005] The main purpose of the present invention is to provide a tread rubber composition, a tread rubber and a tire for low-temperature ice surfaces, so as to solve the problem that the tire tread rubber in the prior art is difficult to have high cold resistance, high ice grip performance and excellent mechanical properties at the same time.

[0006] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a tread rubber composition, which comprises, by weight: 30 to 70 parts of natural rubber, 10 to 40 parts of butadiene rubber, 15 to 30 parts of modified trioctyl phosphate, 5 to 20 parts of nano-diene, 40 to 60 parts of white carbon black, 2 to 4 parts of zinc oxide, 3 to 10 parts of silane coupling agent, 1 to 2 parts of stearic acid, 1 to 2 parts of sulfur, 1 to 3 parts of accelerator and 3 to 10 parts of anti-aging agent.

[0007] Furthermore, the tread rubber composition includes, by weight: 40-60 parts of natural rubber, 30-40 parts of butadiene rubber, 20-30 parts of modified trioctyl phosphate, 5-15 parts of nano-diene, 50-60 parts of white carbon black, 2-3 parts of zinc oxide, 4-7 parts of silane coupling agent, 1.5-2 parts of stearic acid, 1.5-2 parts of sulfur, 2-3 parts of accelerator and 5-10 parts of anti-aging agent.

[0008] Furthermore, the modified trioctyl phosphate is trioctyl phosphate modified by epoxy fatty acid monoester monomers.

[0009] Furthermore, the preparation process of modified trioctyl phosphate includes: after mixing trioctyl phosphate, epoxy fatty acid monoester modified monomer and catalyst, reacting at 50°C to 65°C for 120min to 150min to obtain modified trioctyl phosphate; preferably, the weight ratio of trioctyl phosphate to epoxy fatty acid monoester modified monomer is (1.5 to 4.0):1, more preferably (2.0 to 3.5):1; preferably, the weight ratio of trioctyl phosphate to epoxy fatty acid monoester modified monomer is 100%, and the amount of catalyst added is 8% to 15%; more preferably, the catalyst is butyl titanate.

[0010] Furthermore, the epoxy fatty acid monoester modified monomer is selected from one or more of epoxy oleic acid butyl ester, epoxy oleic acid octyl ester and tetrahydrofurfuryl alcohol ester, preferably epoxy oleic acid butyl ester.

[0011] Furthermore, the particle size of the nano-diene is 40nm to 65nm.

[0012] Furthermore, the weight ratio of nano-diene to white carbon black is 1:(6-12).

[0013] Furthermore, the nitrogen adsorption specific surface area of ​​white carbon black is 80m 2 / g~120m 2 / g.

[0014] Further, the silane coupling agent is selected from one or more of sulfide silane coupling agents, mercapto silane coupling agents, vinyl silane coupling agents and chlorosilane coupling agents, preferably sulfide silane coupling agents and / or mercapto silane coupling agents; and / or, the accelerator is selected from one or more of N-cyclohexyl-2-benzothiazole sulfenamide, diphenylguanidine, N-tert-butyl-2-benzothiazole sulfenamide and 2,2'-dithiodibenzothiazole; and / or, the anti-aging agent is selected from at least two of anti-aging agent 4020, anti-aging agent RD and protective wax.

[0015] The second aspect of the present invention provides a tread rubber, which is obtained by mixing the above tread rubber composition.

[0016] Further, the mixing includes first-stage mixing, second-stage mixing and third-stage mixing, and: the first-stage mixing includes: mixing natural rubber, butadiene rubber, modified trioctyl phosphate, nano diene, white carbon black, silane coupling agent, stearic acid and anti-aging agent, and then mixing to obtain a first-stage mixing masterbatch; the second-stage mixing includes: mixing the first-stage mixing masterbatch with zinc oxide, and then mixing to obtain a second-stage mixing masterbatch; the third-stage mixing includes: mixing the second-stage mixing masterbatch, sulfur After sulfur and accelerator are mixed, three-stage mixing is carried out to obtain tread rubber; preferably, the speed of the internal mixer used for the first mixing is 40rpm~60rpm, and the temperature is 140℃~155℃; and / or, preferably, the speed of the internal mixer used for the second mixing is 45rpm~55rpm, and the temperature is 140℃~155℃; and / or, preferably, the speed of the internal mixer used for the third mixing is 30rpm~40rpm, and the temperature is 90℃~110℃.

[0017] The third aspect of the present invention provides a low-temperature ice tire, the raw material of the tread material of the low-temperature ice tire is the above-mentioned tread rubber composition, and the use condition of the low-temperature ice tire is -20°C to 0°C.

[0018] By applying the technical solution of the present invention, the grip and wear resistance of the obtained tread rubber composition under low-temperature icy conditions are significantly improved by optimizing the formula and material selection. In particular, the introduction of modified trioctyl phosphate enhances the low-temperature performance and wet skid resistance of the rubber, while the use of nano-diene further improves the mechanical strength and cold resistance of the material. The tread rubber composition provided by the present invention has high cold resistance and ice grip, and can significantly improve the safety and service life of the tire under low-temperature icy conditions. DETAILED DESCRIPTION

[0019] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0020] As described in the background art, the tire tread rubber in the prior art has the problem of being difficult to simultaneously possess high cold resistance, high ice grip performance and excellent mechanical properties. In order to solve the above technical problems, the first aspect of the present invention provides a tread rubber composition, which comprises, by weight: 30 to 70 parts of natural rubber, 10 to 40 parts of butadiene rubber, 15 to 30 parts of modified trioctyl phosphate, 5 to 20 parts of nano diene, 40 to 60 parts of white carbon black, 2 to 4 parts of zinc oxide, 3 to 10 parts of silane coupling agent, 1 to 2 parts of stearic acid, 1 to 2 parts of sulfur, 1 to 3 parts of accelerator and 3 to 10 parts of anti-aging agent.

[0021] The present invention obtains the above-mentioned tread rubber composition formula by optimizing formula and material selection.Wherein, natural rubber (NR) is the best general-purpose rubber with comprehensive processing performance, high mechanical strength, belongs to self-reinforcing rubber, and its corresponding vulcanized rubber has very high elasticity and good processing performance, and elasticity is second only to cis-1,4-dimethyl-1-butyl rubber in general-purpose rubber, low glass transition temperature, good cold resistance and wear resistance, and small heat generation.Cis-1,4-dimethyl-1-butyl rubber (BR) has very low Tg, has the best elasticity and cold resistance in general-purpose rubber, can maintain good softness at low temperatures, improves the actual contact area with the ice surface, has good grip performance on dry ice, small hysteresis loss, low dynamic heat generation, can reduce the rolling resistance of tread rubber, and wear resistance and flex resistance are also excellent.But, adding cis-1,4-dimethyl-1-butyl rubber easily makes wet grip performance decline. By using the above two together, especially strictly controlling the weight of natural rubber to 30-70 parts and the weight of butadiene rubber to 10-40 parts, the two can successfully achieve functional complementarity, and the rubber can obtain excellent low-temperature elasticity without losing wear resistance, and have higher grip on ice. At the same time, in order to obtain better wear resistance, the natural rubber used in the present invention is NR commonly used in the tire field, rather than any modified NR.

[0022] And, in several preferred embodiments, in order to obtain better wear resistance and rolling resistance performance, the butadiene rubber used in the present invention is neodymium-based butadiene rubber.

[0023] It should be emphasized that the modified trioctyl phosphate used in the present invention can be used as a component with a softening function to significantly improve the grip and wear resistance of the tread rubber composition under low-temperature ice conditions. Specifically, trioctyl phosphate is relatively stable at room temperature and pressure, has excellent flame resistance, and is often used as a flame retardant, extractant and plasticizer. Especially as a plasticizer, trioctyl phosphate has excellent low-temperature performance, which is better than traditional adipic acid esters, and is less harmful to the human body and the environment than phthalates. When it is added to rubber as a plasticizer alone, it can make the rubber product have the advantages of cold resistance, bacteria resistance and low volatility. The present invention innovatively further modifies it to obtain modified trioctyl phosphate, and uses it as a special plasticizer to obtain a modified tread rubber, which more significantly improves the low-temperature performance of the tread rubber, greatly increases the contact area between the tread rubber and the ice surface, and thus obtains excellent ice grip.

[0024] On this basis, the use of nano-diene further improves the comprehensive performance of the rubber composition. It is a nano-sized diene polymer made of chemically cross-linked rubber particles obtained by emulsion polymerization. Nano-diene has a dense structure and will not absorb low-molecular components (accelerators, sulfur, oils, anti-aging agents, etc.) in the rubber compound, so it can maintain the stability of the rubber composition and effectively improve its mechanical strength and cold resistance.

[0025] At the same time, the white carbon black in the rubber composition formula provided by the present invention has a large number of polar groups on its surface and is highly hydrophilic. Under wet conditions, water molecules can pass through the rubber matrix and adsorb on the surface of the white carbon black particles. At the same time, the white carbon black may be exposed to the outer surface of the rubber. Compared with carbon black, it is a filler with a higher modulus and greater hardness, which can make the surface of the rubber have a higher microhardness, can pierce the water film, is conducive to the contact between the rubber and the road surface, and improves the anti-slip performance. At the same time, the addition of white carbon black can slow down the speed at which the hardness of the tread rubber increases as the external temperature decreases, which is beneficial to anti-ice slip. In addition, the adsorption of the water film on wet ice is also beneficial to the grip of the ice surface. However, unlike carbon black, white carbon black is prone to form agglomerates due to the presence of surface silanol groups and strong surface hydrogen bonding, and has poor compatibility with non-polar rubbers and poor dispersibility, which can easily lead to a decline in performance. Therefore, in order to weaken the filler-filler network effect, the present invention correspondingly adopts 3 to 10 parts by weight of silane coupling agent in combination with it, thereby obtaining a rubber composition that can take into account both high ice grip performance and wear resistance.

[0026] The tread rubber composition provided by the present invention having the above-mentioned special components and contents not only has high cold resistance and ice grip, and can significantly improve the safety and service life of the tire in a low-temperature ice environment, but also exhibits high mechanical properties, especially tensile strength and elongation at break, thereby being able to better meet the application needs in various fields.

[0027] Based on the above formula, the inventors further optimized the dosage of each component through a large number of experiments, and obtained several more preferred embodiments with better cold resistance and ice grip, namely: in parts by weight, the tread rubber composition includes: 40-60 parts of natural rubber, 30-40 parts of butadiene rubber, 20-30 parts of modified trioctyl phosphate, 5-15 parts of nano-diene, 50-60 parts of white carbon black, 2-3 parts of zinc oxide, 4-7 parts of silane coupling agent, 1.5-2 parts of stearic acid, 1.5-2 parts of sulfur, 2-3 parts of accelerator and 5-10 parts of anti-aging agent.

[0028] Furthermore, in order to further improve the migration resistance and low temperature performance of modified trioctyl phosphate, the inventors preferably select the modified trioctyl phosphate as trioctyl phosphate modified with epoxy fatty acid monoester monomers after a large number of experiments, because the epoxy fatty acid monoester modified monomers not only have good low temperature performance and good plasticizing effect, but also show better compatibility with trioctyl phosphate, and can also improve the compatibility of trioctyl phosphate with the rubber matrix without affecting the cold resistance.

[0029] In practical applications, the modified monomer can also be selected from sebacic acid polyester plasticizers or tetrahydrofurfuryl alcohol esters. Sebacic acid polyester plasticizers have low volatility and migration, and can significantly improve the migration resistance of trioctyl phosphate and the resulting tread rubber composition. Tetrahydrofurfuryl alcohol ester, as a nucleophilic alcohol ester, can enhance the wear resistance of trioctyl phosphate when used as a modified monomer. It can also improve its antioxidant properties.

[0030] The preparation of trioctyl phosphate is generally prepared by phosphorus oxychloride and isooctyl alcohol under the condition of titanium tetrachloride as a catalyst. The preparation process of modified trioctyl phosphate includes: after mixing trioctyl phosphate, epoxy fatty acid monoester modified monomer and catalyst, reacting at 50°C to 65°C for 120min to 150min to obtain modified trioctyl phosphate. After a large number of experiments, the inventor optimized the preparation method of modified trioctyl phosphate and obtained the above conditions. Especially for the intrinsic properties of trioctyl phosphate, the properties of the modified monomer and the mechanism of the reaction process between the two, a large number of optimization and screening of the reaction time and temperature were carried out, and finally the preparation of modified trioctyl phosphate was realized by the above method, and modified trioctyl phosphate with better performance was obtained with a higher yield, and then a modified tread rubber with better cold resistance, wear resistance and ice grip was obtained.

[0031] More preferably, the inventors further mixed trioctyl phosphate, epoxy fatty acid monoester modified monomers and catalysts, and reacted them at 55°C to 60°C for 135min to 145min to obtain modified trioctyl phosphate, which exhibited higher intrinsic cold resistance and wear resistance under these preparation conditions, and also showed higher compatibility with other components in the tread rubber composition formula, and the obtained tread rubber composition had better comprehensive performance.

[0032] In order to better exert the reinforcing effect of epoxy fatty acid monoester modified monomers on the various properties of trioctyl phosphate, and thus optimize the cold resistance and ice grip performance of the obtained tread rubber composition, the weight ratio of trioctyl phosphate to epoxy fatty acid monoester modified monomers is preferably (1.5-4.0):1. Based on the above modified dosage ratio, the inventor further preferred the weight ratio of trioctyl phosphate to epoxy fatty acid monoester modified monomers to be (2.0-3.5):1 after a large number of experiments, and thus obtained a modified trioctyl phosphate with better intrinsic cold resistance and plasticizing effect, and better compatibility with other components in the formula, especially natural rubber and butadiene rubber, and thus obtained a tread rubber composition with better comprehensive performance, which not only has high cold resistance and ice grip, but also has excellent mechanical properties.

[0033] Furthermore, based on the weight of trioctyl phosphate and epoxy fatty acid monoester modified monomers as 100%, the amount of catalyst added is 8% to 15%, and the catalyst is more preferably butyl titanate, so as to balance the reaction rate and selectivity, obtain modified trioctyl phosphate with better performance, and further improve the cold resistance and wear resistance of the obtained tread rubber composition.

[0034] In several preferred embodiments, the epoxy fatty acid monoester modified monomer is selected from one or more of epoxy oleic acid butyl ester, epoxy oleic acid octyl ester and tetrahydrofurfuryl alcohol ester. In practical applications, the tetrahydrofurfuryl alcohol ester can be tetrahydrofurfuryl acetate, tetrahydrofurfuryl propionate, etc. These epoxy fatty acid monoester modified monomers are more compatible with trioctyl phosphate, so that modified trioctyl phosphate with more significant plasticizing effect can be obtained. After a large number of experiments, the inventors preferred the epoxy fatty acid monoester modified monomer to be epoxy oleic acid butyl ester, which is obtained by esterification of oleic acid and butanol and then epoxidation with hydrogen peroxide. The epoxy value is about 3% to 5%, has good compatibility with the matrix, high plasticization rate, good cold resistance, heat resistance, oil extraction resistance, low volatility, and a flash point of 190°C. After mixing the two, the compatibility of the obtained modified trioctyl phosphate with the system can be more significantly improved, the plasticizing effect can be improved, and then the ability of the obtained tread rubber composition to maintain softness at low temperatures can be improved, and the cold resistance and ice grip can be improved.

[0035] Furthermore, the particle size of the nano diene is 40nm to 65nm. The nano diene within this particle size range can more significantly balance and enhance the mechanical strength and cold ice grip of the tread rubber composition. In practical applications, the nano diene is a Nanoprene series product produced by LANXESS, and the inventor further preferred its model BM 75OH after a large number of experiments.

[0036] It is worth mentioning that the nano-diene used in the present invention is easy to disperse, which makes the tread rubber composition easier to prepare. At the same time, the nano-diene can also effectively reduce the chemical affinity between white carbon black and the metal surface of the mixing equipment, and greatly reduce the "adhesion" of the tread rubber composition. On this basis, the inventors have optimized the weight ratio of nano-diene to white carbon black to be 1: (6-12) after a large number of experiments, so as to better play the role of nano-diene in improving the surface properties of white carbon black, and further significantly improve the "magic triangle performance" of the obtained tread rubber composition, namely wear resistance, rolling resistance, and anti-slip performance.

[0037] In order to achieve better dispersion of white carbon black in the rubber matrix, and thus achieve greater reinforcement effect and make the obtained tread rubber have better mechanical properties, the inventors have optimized the nitrogen adsorption specific surface area of ​​white carbon black to be 80m 2 / g~120m 2 / g.

[0038] Further, the silane coupling agent is selected from one or more of sulfide silane coupling agents, mercapto silane coupling agents, vinyl silane coupling agents and chlorosilane coupling agents, preferably sulfide silane coupling agents and / or mercapto silane coupling agents. These two silane coupling agents have better binding performance with white carbon black and lower heat generation, thereby being able to obtain a tread rubber composition with better comprehensive performance; and / or, the accelerator is selected from one or more of N-cyclohexyl-2-benzothiazole sulfonamide, diphenylguanidine, N-tert-butyl-2-benzothiazole sulfonamide and 2,2'-dithiodibenzothiazole. The above-mentioned accelerators have higher activity and can more effectively promote the vulcanization of the tread rubber composition; and / or, the anti-aging agent is selected from at least two of anti-aging agent 4020, anti-aging agent RD and protective wax.

[0039] And, in a specific application, the silane coupling agent is selected from one or more of Si69, Si747, Si75 and NXT.

[0040] In several more preferred embodiments, the tread rubber composition comprises, by weight: 60 parts by weight of natural rubber, 40 parts by weight of neodymium-based butadiene rubber, 20 parts by weight of modified trioctyl phosphate, 5 parts by weight of nano-diene, 60 parts by weight of white carbon black, 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent, 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD and 2 parts by weight of protective wax; or, by weight, the tread rubber composition comprises: 60 parts by weight of natural rubber, 40 parts by weight of neodymium-based butadiene rubber, 20 parts by weight of modified trioctyl phosphate, 5 parts by weight of nano-diene, 60 parts by weight of white carbon black, 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent, 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD and 2 parts by weight of protective wax. Butadiene rubber, 20 parts by weight of modified trioctyl phosphate, 10 parts by weight of nano diene, 60 parts by weight of white carbon black, 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent, 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD and 2 parts by weight of protective wax; or, by weight, the tread rubber composition comprises: 60 parts by weight of natural rubber, 40 parts by weight of neodymium-based butadiene rubber, 30 parts by weight of modified trioctyl phosphate, 5 parts by weight of nano diene, 60 parts by weight of white carbon black, 3 parts by weight of zinc oxide, 4 parts by weight of a silane coupling agent, 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of an accelerator CZ, 1.2 parts by weight of an accelerator DPG, 1.5 parts by weight of an anti-aging agent 4020, 1.5 parts by weight of an anti-aging agent RD and 2 parts by weight of a protective wax; or, by weight, the tread rubber composition comprises: 60 parts by weight of natural rubber, 40 parts by weight of neodymium-based butadiene rubber, 30 parts by weight of modified trioctyl phosphate, 5 parts by weight of nano-diene, 60 parts by weight of white carbon black, 3 parts by weight of zinc oxide, 4 parts by weight of a silane coupling agent, 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of an accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD and 2 parts by weight of protective wax; or, by weight, the tread rubber composition includes: 60 parts by weight of natural rubber, 40 parts by weight of neodymium-based butadiene rubber, 30 parts by weight of modified trioctyl phosphate, 10 parts by weight of nano-diene, 60 parts by weight of white carbon black, 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent, 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD and 2 parts by weight of protective wax.After a large number of experiments and comparisons, the inventors have selected the above-mentioned tread rubber composition formulas, which more effectively optimize the compatibility, reactivity and coordination between the components, not only improving the low temperature resistance and ice grip performance of the obtained tread rubber composition, but also significantly enhancing its mechanical properties, with higher comprehensive performance.

[0041] The second aspect of the present invention provides a tread rubber, which is obtained by mixing the above tread rubber composition. The obtained tread rubber not only has high cold resistance and ice grip, but also exhibits excellent mechanical properties, and can meet the application requirements of various fields.

[0042] Further, the mixing includes a first-stage mixing, a second-stage mixing and a third-stage mixing, and: the first-stage mixing includes: mixing natural rubber, butadiene rubber, modified trioctyl phosphate, nano diene, white carbon black, silane coupling agent, stearic acid and anti-aging agent, and then mixing in one stage to obtain a first-stage mixing masterbatch; the second-stage mixing includes: mixing the first-stage mixing masterbatch with zinc oxide, and then mixing in two stages to obtain a second-stage mixing masterbatch; the third-stage mixing includes: mixing the second-stage mixing masterbatch, sulfur and an accelerator, and then mixing in three stages to obtain a tread rubber. The tread rubber obtained by the above process has each component dispersed more evenly in the rubber matrix, can play its respective role more fully, and achieve good processing performance.

[0043] With respect to the physicochemical properties of each component in the tread rubber composition formula used, the inventors have preferably, after a large number of experiments, selected a rotating speed of 40 rpm to 60 rpm and a temperature of 140°C to 155°C for the first-stage mixing; and / or, selected a rotating speed of 45 rpm to 55 rpm and a temperature of 140°C to 155°C for the second-stage mixing; and / or, selected a rotating speed of 30 rpm to 40 rpm and a temperature of 90°C to 110°C for the third-stage mixing, and under these conditions, achieved better coordination between the components, thereby obtaining a tread rubber with better comprehensive performance.

[0044] Specifically, in practical applications, the mixing process includes:

[0045] One-stage mixing: add natural rubber and butadiene rubber to the internal mixer, press the top plug for 25s to 30s, lift the weight, add modified trioctyl phosphate, white carbon black, nano diene, silane coupling agent, stearic acid, anti-aging agent, press the top plug for 20s to 30s, lift the weight, press the top plug for 20s to 25s, the internal mixer speed is 40rpm to 60rpm; discharge the rubber at 140℃ to 155℃; the discharged rubber material is extruded by a twin-screw tablet press, dipped in a release agent, cooled and dried, and stacked for parking, which is a one-stage mixing masterbatch.

[0046] Second-stage mixing: add a first-stage mixing masterbatch into the internal mixer, press the top bolt for 25s to 35s, lift the weight, add zinc oxide, press the top bolt for 20s to 25s, lift the weight, and press the top bolt for 20s to 35s; the internal mixer speed is 45rpm to 55rpm, and the rubber is discharged at 140℃ to 155℃; the discharged rubber is tableted by a twin-screw extruder tablet press, dipped in a release agent, cooled and dried, and stacked for storage, which is the second-stage mixing masterbatch.

[0047] Final rubber mixing: Add the second-stage mixing masterbatch, sulfur, and accelerator to the internal mixer, press the top bolt for 20s to 25s, lift the weight, press the top bolt for 20s to 30s, lift the weight, and press the top bolt for 20s to 30s; the internal mixer speed is 30rpm to 40rpm, and the rubber is discharged at 90℃ to 110℃; the discharged rubber is tableted by a twin-screw extruder tablet press, and the left and right cutters on the open mixer are cut 3 to 4 times each. After the tablets are discharged, the release agent is dipped, cooled and dried, and stacked to obtain the tread rubber.

[0048] The third aspect of the present invention provides a low-temperature ice tire, the raw material of the tread material of the low-temperature ice tire is the above-mentioned tread rubber composition, and the use conditions of the low-temperature ice tire are -20°C to 0°C. Since the above-mentioned tread rubber composition provided by the present invention has high cold resistance and anti-ice skid performance, and also exhibits excellent tensile strength and wear resistance and other mechanical properties, it can be used as a tread material for low-temperature ice tires, and a cold-resistant tire with good ice grip performance suitable for winter, especially in a low-temperature environment of -20°C to 0°C, is prepared. The tire exhibits excellent grip and wear resistance in a low-temperature ice environment, which not only improves the safety of winter driving, but also prolongs the service life of the tire, providing a more reliable choice for winter driving, and is particularly suitable for vehicles in winter ski resorts and ice lake areas.

[0049] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0050] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0051] Example 1

[0052] A method for preparing tread rubber:

[0053] The composition components selected in this embodiment are: 60 parts by weight of natural rubber (NR), 40 parts by weight of neodymium-based butadiene rubber (BR), 20 parts by weight of modified trioctyl phosphate, 5 parts by weight of Nanoprene (model BM 75OH) with a particle size of 50 nm, and 60 parts by weight of a nitrogen adsorption specific surface area of ​​120 m 2 / g of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:12), 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent (model Si69), 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator N-cyclohexyl-2-benzothiazole sulfonamide (CZ), 1.2 parts by weight of accelerator diphenylguanidine (DPG), 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD and 2 parts by weight of protective wax.

[0054] The preparation method of modified trioctyl phosphate is as follows: trioctyl phosphate and epoxy butyl oleate are mixed in a mass ratio of trioctyl phosphate: epoxy butyl oleate = 2:1, and 10% of butyl titanate is added as a catalyst based on the total weight of the two being 100% to obtain a mixed system; the mixed system is heated at a temperature of 55°C for 135 minutes to obtain modified trioctyl phosphate.

[0055] The preparation method of the tread rubber is as follows:

[0056] One-stage mixing: add natural rubber and butadiene rubber to the internal mixer, press the top plug for 30 seconds, lift the weight, add modified trioctyl phosphate, white carbon black, nano diene, silane coupling agent, stearic acid, anti-aging agent, press the top plug for 30 seconds, lift the weight, press the top plug for 25 seconds, and the internal mixer speed is 60rpm; discharge the rubber at 155℃; the discharged rubber material is extruded by a twin-screw tablet press, and then cooled and dried after being dipped in a release agent, and stacked and parked, which is the one-stage mixing masterbatch.

[0057] Second-stage mixing: add a first-stage mixing masterbatch to the internal mixer, press the top bolt for 35 seconds, lift the weight, add zinc oxide, press the top bolt for 25 seconds, lift the weight, and press the top bolt for 20 seconds; the internal mixer speed is 45rpm, and the rubber is discharged at 155℃; the discharged rubber is tableted by a twin-screw extruder tablet press, dipped in a release agent, cooled and dried, and stacked for storage, which is the second-stage mixing masterbatch.

[0058] Final rubber mixing: Add the second-stage mixing masterbatch, sulfur, and accelerator to the internal mixer, press the top bolt for 20 seconds, lift the weight, press the top bolt for 20 seconds, lift the weight, and press the top bolt for 20 seconds; the internal mixer speed is 30rpm, and the rubber is discharged at 90℃; the discharged rubber is extruded by a twin-screw extruder tablet press, and the left and right cutters on the open mixer are cut 3 times each. After the tablets are discharged, the release agent is dipped, cooled and dried, and stacked to obtain the tread rubber.

[0059] Example 2

[0060] A method for preparing tread rubber:

[0061] The difference between this embodiment and embodiment 1 is that the preparation method of modified trioctyl phosphate is different. Specifically, trioctyl phosphate and butyl oleate are mixed in a mass ratio of trioctyl phosphate:butyl oleate=3.5:1, and 8% butyl titanate is added as a catalyst based on the total weight of the two being 100% to obtain a mixed system; the mixed system is heated at a temperature of 60°C for 145 minutes to obtain modified trioctyl phosphate.

[0062] Example 3

[0063] A method for preparing tread rubber:

[0064] The difference between this embodiment and embodiment 1 is that the preparation method of modified trioctyl phosphate is different. Specifically, trioctyl phosphate and butyl oleate are mixed in a mass ratio of trioctyl phosphate:butyl oleate=1.5:1, and 15% of butyl titanate is added as a catalyst based on the total weight of the two being 100% to obtain a mixed system; the mixed system is heated at a temperature of 50°C for 120 minutes to obtain modified trioctyl phosphate.

[0065] Example 4

[0066] A method for preparing a tread rubber composition:

[0067] The difference between this embodiment and embodiment 1 is that the preparation method of modified trioctyl phosphate is different. Specifically, trioctyl phosphate and butyl oleate are mixed at a mass ratio of trioctyl phosphate:butyl oleate=4.0:1, and 10% of butyl titanate is added as a catalyst based on the total weight of the two being 100% to obtain a mixed system; the mixed system is heated at a temperature of 65°C for 150 minutes to obtain modified trioctyl phosphate.

[0068] Example 5

[0069] A method for preparing tread rubber:

[0070] The only difference between this embodiment and embodiment 1 is that in the preparation method of modified trioctyl phosphate, an equal weight of butyl epoxyacrylate is used to replace butyl epoxyoleate.

[0071] Example 6

[0072] A method for preparing tread rubber:

[0073] The only difference between this embodiment and embodiment 1 is that in the preparation method of modified trioctyl phosphate, an equal weight of polyethylene adipate is used to replace epoxy butyl oleate.

[0074] Example 7

[0075] A method for preparing tread rubber:

[0076] The only difference between this embodiment and embodiment 1 is that the nitrogen adsorption specific surface area of ​​white carbon black is changed to 80m 2 / g, and its dosage is changed to 30 parts by weight, at which time the weight ratio of nano-diene to white carbon black is 1:6.

[0077] Example 8

[0078] A method for preparing tread rubber:

[0079] The only difference between this embodiment and embodiment 1 is that the nitrogen adsorption specific surface area of ​​white carbon black is changed to 50m 2 / g, and its dosage is changed to 25 parts by weight, at which time the weight ratio of nano-diene to white carbon black is 1:5.

[0080] Example 9

[0081] A method for preparing tread rubber:

[0082] The only difference between this embodiment and embodiment 1 is that the nitrogen adsorption specific surface area of ​​white carbon black is changed to 150m 2 / g, and its dosage is changed to 75 parts by weight. At this time, the weight ratio of nano-diene to white carbon black is 1:15.

[0083] Example 10

[0084] A method for preparing tread rubber:

[0085] The difference between this embodiment and embodiment 1 is only that the contents of the components are different, specifically: 60 parts by weight of NR, 40 parts by weight of BR, 20 parts by weight of modified trioctyl phosphate, 10 parts by weight of BM 75OH, 60 parts by weight of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:6), 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent, 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD, and 2 parts by weight of protective wax. The preparation method, physicochemical properties, and model of each component are all consistent with those of embodiment 1.

[0086] Embodiment 11

[0087] A method for preparing tread rubber:

[0088] The difference between this embodiment and embodiment 1 is only that the contents of the components are different, specifically: 60 parts by weight of NR, 40 parts by weight of BR, 30 parts by weight of modified trioctyl phosphate, 5 parts by weight of BM 75OH, 60 parts by weight of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:12), 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent, 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD, and 2 parts by weight of protective wax. The preparation method, physicochemical properties, and model of each component are all consistent with those of embodiment 1.

[0089] Example 12

[0090] A method for preparing tread rubber:

[0091] The difference between this embodiment and embodiment 1 is only that the contents of the components are different, specifically: 60 parts by weight of NR, 40 parts by weight of BR, 30 parts by weight of modified trioctyl phosphate, 10 parts by weight of BM 75OH, 60 parts by weight of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:6), 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent, 2 parts by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD, and 2 parts by weight of protective wax. The preparation method, physicochemical properties, and model of each component are all consistent with those of embodiment 1.

[0092] Example 13

[0093] A method for preparing tread rubber:

[0094] The difference between this embodiment and embodiment 1 is only that the contents of the components are different, specifically: 70 parts by weight of NR, 30 parts by weight of BR, 20 parts by weight of modified trioctyl phosphate, 5 parts by weight of BM 75OH, 60 parts by weight of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:12), 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent, 2 parts by weight of stearic acid, 1 part by weight of sulfur, 0.5 parts by weight of accelerator CZ, 0.5 parts by weight of accelerator DPG, 1 part by weight of anti-aging agent 4020, 1 part by weight of anti-aging agent RD and 1 part by weight of protective wax. The preparation method, physicochemical properties and models of the components are all the same as those of embodiment 1.

[0095] Embodiment 14

[0096] A method for preparing tread rubber:

[0097] The difference between this embodiment and embodiment 1 is only that the contents of the components are different, specifically: 70 parts by weight of NR, 30 parts by weight of BR, 20 parts by weight of modified trioctyl phosphate, 10 parts by weight of BM 75OH, 60 parts by weight of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:6), 3 parts by weight of zinc oxide, 4 parts by weight of silane coupling agent, 2 parts by weight of stearic acid, 1 part by weight of sulfur, 0.5 parts by weight of accelerator CZ, 0.5 parts by weight of accelerator DPG, 1 part by weight of anti-aging agent 4020, 1 part by weight of anti-aging agent RD and 1 part by weight of protective wax. The preparation method, physicochemical properties and models of the components are all the same as those of embodiment 1.

[0098] Embodiment 15

[0099] A method for preparing tread rubber:

[0100] The difference between this embodiment and embodiment 1 is only that the contents of the components are different, specifically: 70 parts by weight of NR, 30 parts by weight of BR, 30 parts by weight of modified trioctyl phosphate, 5 parts by weight of BM 75OH, 60 parts by weight of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:6), 4 parts by weight of zinc oxide, 3 parts by weight of silane coupling agent, 1 part by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD, and 2 parts by weight of protective wax. The preparation method, physicochemical properties, and model of each component are all consistent with those of embodiment 1.

[0101] Example 16

[0102] A method for preparing tread rubber:

[0103] The difference between this embodiment and embodiment 1 is only that the contents of the components are different, specifically: 70 parts by weight of NR, 30 parts by weight of BR, 30 parts by weight of modified trioctyl phosphate, 10 parts by weight of BM 75OH, 60 parts by weight of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:6), 4 parts by weight of zinc oxide, 3 parts by weight of silane coupling agent, 1 part by weight of stearic acid, 1.8 parts by weight of sulfur, 1.5 parts by weight of accelerator CZ, 1.2 parts by weight of accelerator DPG, 1.5 parts by weight of anti-aging agent 4020, 1.5 parts by weight of anti-aging agent RD, and 2 parts by weight of protective wax. The preparation method, physicochemical properties, and model of each component are all consistent with those of embodiment 1.

[0104] Comparative Example 1

[0105] A method for preparing tread rubber:

[0106] The difference between this comparative example and Example 1 is that modified trioctyl phosphate and nano-diene are not added, and 30 parts by weight of environmentally friendly aromatic oil (TDAE) are additionally added.

[0107] Comparative Example 2

[0108] A method for preparing tread rubber:

[0109] The only difference between this comparative example and Example 13 is that modified trioctyl phosphate and nano-diene are not added, and 30 parts by weight of TDAE are additionally added.

[0110] Comparative Example 3

[0111] A method for preparing tread rubber:

[0112] The difference between this comparative example and Example 1 is only that the contents of each component are different, specifically: 80 parts by weight of NR, 5 parts by weight of BR, 10 parts by weight of modified trioctyl phosphate, 2 parts by weight of BM 75OH, 70 parts by weight of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:7), 1 part by weight of zinc oxide, 2 parts by weight of silane coupling agent, 0.5 parts by weight of stearic acid, 0.5 parts by weight of sulfur, 0.5 parts by weight of accelerator CZ, 0.5 parts by weight of anti-aging agent 4020, 0.5 parts by weight of anti-aging agent RD, and 1 part by weight of protective wax. The preparation method, physicochemical properties, and model of each component are all consistent with those of Example 1.

[0113] Comparative Example 4

[0114] A method for preparing tread rubber:

[0115] The difference between this comparative example and Example 1 is only that the contents of each component are different, specifically: 20 parts by weight of NR, 50 parts by weight of BR, 40 parts by weight of modified trioctyl phosphate, 30 parts by weight of BM 75OH, 30 parts by weight of white carbon black (i.e., the weight ratio of nano-diene to white carbon black is 1:1), 5 parts by weight of zinc oxide, 15 parts by weight of silane coupling agent, 3 parts by weight of stearic acid, 3 parts by weight of sulfur, 5 parts by weight of accelerator CZ, 3 parts by weight of anti-aging agent 4020, 3 parts by weight of anti-aging agent RD, and 6 parts by weight of protective wax. The preparation method, physicochemical properties, and model of each component are all the same as those of Example 1.

[0116] Comparative Example 5

[0117] A method for preparing tread rubber:

[0118] The difference between this comparative example and Example 1 is that the original modified trioctyl phosphate is replaced by an equal weight of unmodified trioctyl phosphate. The amounts, preparation methods, physicochemical properties and models of the other components are the same as those of Example 1.

[0119] The component contents of the above-mentioned embodiments and comparative examples are shown in Table 1-1, Table 1-2 and Table 1-3.

[0120] Table 1-1

[0121]

[0122]

[0123] Table 1-2

[0124]

[0125] Table 1-3

[0126]

[0127]

[0128] Test Method

[0129] Tensile strength and elongation at break: At room temperature, use a constant speed tensile testing machine as the testing instrument and test according to GB / T528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0130] E'(-20℃), tanδ(0℃) and tanδ(60℃): Temperature scanning of each sample was performed in tensile mode on a dynamic mechanical properties spectrometer. The test conditions were: temperature range of -60~60℃, heating rate of 2℃ / min, static strain of 7%, dynamic strain of 0.25%, frequency of 10Hz, and E'(-20℃), tanδ(0℃) and tanδ(60℃) were obtained. E'(-20℃) is used to characterize the low-temperature ice and snow braking performance of the rubber composition; tanδ(0℃) is used to characterize the wet grip performance of the rubber composition; and tanδ(60℃) is used to characterize the rolling resistance of the rubber composition.

[0131] Friction coefficient μ: Use LAT100 wear tester to test the ice grip and wet skid performance of tread rubber. Under a certain program of load, speed, slip angle, distance and temperature, the rubber wheel sample is fixed, and driven by the TCD disk, the sample slides on the ice surface, and the longitudinal force Fx is measured by the three-dimensional force sensor, and the friction coefficient and friction coefficient grade are calculated. Each sample is tested at least once on the left and right sides, and the results are taken as the arithmetic average. Test conditions: slip angle of 0°, speed of 0.6km / h, load of 75N, temperature of -5, -10, -15℃.

[0132] The above test was performed on the rubber obtained from each embodiment and comparative example. At the same time, for the convenience of comparison, the test result of comparative example 1 was used as the basic index, and its value was set to 100. The results obtained from the other embodiments and comparative examples were converted relative to the test result of comparative example 1, and the test index was obtained respectively. The higher the test index, the better the corresponding performance is compared with comparative example 1. The specific conversion results are shown in Table 2.

[0133] Table 2

[0134]

[0135] From the above description, it can be seen that the above embodiments of the present invention use the new softener modified trioctyl phosphate and the special additive Nanoprene, so the obtained tread rubber has better cold resistance, more excellent related performance indexes, higher icy friction coefficient, and more superior ice grip performance.

[0136] By comparing the various examples, it can be found that with the introduction of modified phosphate ester and Nanoprene, the low-temperature modulus and ice friction coefficient of the relevant examples are increased to varying degrees, while maintaining stable tensile properties, reflecting that the addition of modified trioctyl phosphate and Nanoprene can keep the tread rubber soft at low temperatures, achieve greater contact with the ice surface, and greatly improve the ice grip performance of the tread rubber. Specifically:

[0137] Comparing Examples 1, 7, 10, 11, and 12 with Examples 13 to 16, it can be seen that when the tread rubber composition includes, by weight, 40 to 60 parts of natural rubber, 30 to 40 parts of butadiene rubber, 20 to 30 parts of modified trioctyl phosphate, 5 to 15 parts of nano-diene, 50 to 60 parts of white carbon black, 2 to 3 parts of zinc oxide, 4 to 7 parts of silane coupling agent, 1.5 to 2 parts of stearic acid, 1.5 to 2 parts of sulfur, 2 to 3 parts of accelerator and 5 to 10 parts of anti-aging agent, the tread rubber composition obtained after mixing to obtain the tread rubber has improved ice and snow braking performance at low temperature and grip performance in wetland environment.

[0138] Comparing Examples 1 and 2 with Examples 3 and 4, it can be seen that in the preparation process of modified trioctyl phosphate, the preferred addition ratio of the modified monomer and the reaction conditions in the modification process can enable the obtained modified trioctyl phosphate to exert higher cold resistance and ice grip in the tread rubber composition.

[0139] Comparing Examples 1 and 2 with Examples 5 and 6, it can be seen that the selection of the modified monomer is equally important. Compared with other types of modified monomers, epoxy fatty acid monoester monomers can significantly improve the compatibility of trioctyl phosphate with the rubber matrix without affecting the cold resistance, thereby enhancing its comprehensive performance.

[0140] Comparing Examples 1 and 7 with Examples 8 and 9, it can be seen that the preferred weight ratio of nano-diene to white carbon black is 1:(6-12), which can significantly improve the wear resistance and wet skid resistance of the obtained tread rubber composition.

[0141] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0142] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tread rubber composition, characterized in that: The tread rubber composition comprises, by weight, 30 to 70 parts of natural rubber, 10 to 40 parts of butadiene rubber, 15 to 30 parts of modified trioctyl phosphate, 5 to 20 parts of nano-diene, 40 to 60 parts of white carbon black, 2 to 4 parts of zinc oxide, 3 to 10 parts of silane coupling agent, 1 to 2 parts of stearic acid, 1 to 2 parts of sulfur, 1 to 3 parts of accelerator and 3 to 10 parts of anti-aging agent.

2. The tread rubber composition according to claim 1, characterized in that: In parts by weight, the tread rubber composition includes: 40 to 60 parts of the natural rubber, 30 to 40 parts of the butadiene rubber, 20 to 30 parts of the modified trioctyl phosphate, 5 to 15 parts of the nano-diene, 50 to 60 parts of the white carbon black, 2 to 3 parts of the zinc oxide, 4 to 7 parts of the silane coupling agent, 1.5 to 2 parts of the stearic acid, 1.5 to 2 parts of the sulfur, 2 to 3 parts of the accelerator and 5 to 10 parts of the anti-aging agent.

3. The tread rubber composition according to claim 1 or 2, characterized in that: The modified trioctyl phosphate is trioctyl phosphate modified by epoxy fatty acid monoester monomers.

4. The tread rubber composition according to claim 3, characterized in that: The preparation process of the modified trioctyl phosphate comprises: After mixing trioctyl phosphate, epoxy fatty acid monoester modified monomer and catalyst, reacting at 50° C. to 65° C. for 120 min to 150 min to obtain the modified trioctyl phosphate; Preferably, the weight ratio of the trioctyl phosphate to the epoxy fatty acid monoester modified monomer is (1.5-4.0):1, more preferably (2.0-3.5):1; Preferably, the amount of the catalyst added is 8% to 15%, based on the weight of the trioctyl phosphate and the epoxy fatty acid monoester modified monomer being 100%; More preferably, the catalyst is butyl titanate.

5. The tread rubber composition according to claim 4, characterized in that: The epoxy fatty acid monoester modified monomer is selected from one or more of epoxy oleic acid butyl ester, epoxy oleic acid octyl ester and tetrahydrofurfuryl alcohol ester, preferably epoxy oleic acid butyl ester.

6. The tread rubber composition according to any one of claims 1 to 5, characterized in that: The particle size of the nano-diene is 40nm-65nm.

7. The tread rubber composition according to any one of claims 1 to 6, characterized in that: The weight ratio of the nano-diene to the white carbon black is 1:(6-12).

8. The tread rubber composition according to any one of claims 1 to 7, characterized in that: The nitrogen adsorption specific surface area of ​​the white carbon black is 80 m 2 / g~120m 2 / g.

9. The tread rubber composition according to any one of claims 1 to 8, characterized in that: The silane coupling agent is selected from one or more of a sulfide silane coupling agent, a mercapto silane coupling agent, a vinyl silane coupling agent and a chlorosilane coupling agent, preferably a sulfide silane coupling agent and / or a mercapto silane coupling agent; and / or, the accelerator is selected from one or more of N-cyclohexyl-2-benzothiazole sulfenamide, diphenylguanidine, N-tert-butyl-2-benzothiazole sulfenamide and 2,2'-dibenzothiazole disulfide; And / or, the anti-aging agent is selected from at least two of anti-aging agent 4020, anti-aging agent RD and protective wax.

10. A tread rubber, characterized in that: The tread rubber is obtained by kneading the tread rubber composition according to any one of claims 1 to 9.

11. The tread rubber according to claim 10, characterized in that: The mixing includes one-stage mixing, two-stage mixing and three-stage mixing performed sequentially, and: The one-stage mixing comprises: mixing the natural rubber, the butadiene rubber, the modified trioctyl phosphate, the nano-diene, the white carbon black, the silane coupling agent, the stearic acid and the anti-aging agent, and then performing the one-stage mixing to obtain a one-stage mixing masterbatch; The two-stage mixing comprises: mixing the first-stage mixing masterbatch with the zinc oxide, and then performing the second-stage mixing to obtain the second-stage mixing masterbatch; The three-stage mixing comprises: mixing the two-stage mixing masterbatch, the sulfur and the accelerator, and then performing the three-stage mixing to obtain the tread rubber; Preferably, the speed of the internal mixer used in the first stage of mixing is 40 rpm to 60 rpm, and the temperature is 140° C. to 155° C.; and / or, Preferably, the speed of the internal mixer used in the second-stage mixing is 45 rpm to 55 rpm, and the temperature is 140° C. to 155° C.; and / or, Preferably, the internal mixer used for the three-stage mixing has a rotation speed of 30 rpm to 40 rpm and a temperature of 90° C. to 110° C.

12. A tire for low-temperature ice surfaces, characterized in that: The raw material of the tread material of the low-temperature ice tire is the tread rubber composition according to any one of claims 1 to 9, and the use condition of the low-temperature ice tire is -20°C to 0°C.

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