A tire tread rubber for new energy heavy trucks and its preparation method and application

Abstract

The present application discloses a tire tread rubber, preparation method and application for new energy heavy trucks, and belongs to the technical field of tire preparation for new energy heavy trucks. The tread rubber includes: 13-17 parts of butadiene rubber, 30-35 parts of low molecular weight trans-butadiene-polyisoprene rubber, 30-40 parts of styrene-butadiene rubber, 35-40 parts of carbon black, 10-15 parts of modified white carbon black, 2-3 parts of vulcanizing agent, 3-5 parts of activator, 2-5 parts of antioxidant, 1-2 parts of accelerator, 1-2 parts of scorch retarder; the modified white carbon black is obtained by modification with sulfaguanidine, activated silica gel and dopamine. The modified white carbon black used in the tread rubber can participate in the cross-linking reaction of the rubber matrix, thereby further improving the dispersibility of white carbon black, thereby synergistically improving the various aspects of the tread rubber performance, especially improving the low noise, grip and puncture resistance of the tire.

Description

Technical Field

[0001] The present application relates to a tire tread rubber for new energy heavy-duty trucks, a preparation method and an application thereof, and belongs to the technical field of tire preparation for new energy heavy-duty trucks. Background Art

[0002] The new energy truck industry is in a rapid growth stage, showing strong market potential and development momentum. At present, the market demand for new energy heavy-duty trucks continues to grow. It is predicted that by 2025, the domestic market penetration rate of new energy heavy-duty trucks will exceed 10%, and by 2030 this figure will be close to 50%. This shows that new energy heavy-duty trucks will play an increasingly important role in future logistics and transportation.

[0003] Tires are key components to ensure the normal operation of heavy-duty trucks. The basic requirements for tires are: first, they can carry high loads and have strong traction; second, they have high braking performance and good buffering; third, they have strong grip and directional stability; fourth, they have high wear resistance, durability, safety, and low rolling resistance. Since the energy supply system of new energy heavy-duty trucks produces almost no noise, in addition to meeting the above requirements, new energy heavy-duty trucks must also reduce the noise of tires during operation. In addition, some new energy heavy-duty trucks need to operate on harsh surfaces such as mountainous areas and mining areas, which requires tires to have higher grip and good puncture resistance, tear resistance, and impact resistance.

[0004] At present, some researchers have also made outstanding contributions to the above requirements. For example, patent CN111675828A uses low molecular weight trans-butadiene-polyisoprene copolymer that can participate in vulcanization cross-linking in tire tread rubber, which can improve the processing and mixing performance of the rubber and participate in the role of vulcanization cross-linking, so that the mechanical properties, tear resistance and wear resistance of the vulcanized rubber are improved. However, it does not focus on how to improve the low noise, grip and puncture resistance of the tire. Summary of the invention

[0005] In order to solve the above problems, a tire tread rubber for new energy heavy-duty trucks is provided. The tread rubber uses low molecular weight trans-butadiene-polyisoprene rubber and butadiene rubber as a matrix, and adopts styrene-butadiene rubber as an intermediate blending agent between the two. The modified silica used can participate in the cross-linking reaction of the rubber matrix, thereby further improving the dispersibility of silica. The above characteristics can synergistically improve various performances of the tread rubber, especially improve the low noise, grip and puncture resistance of the tire.

[0006] According to one aspect of the present application, a tire tread rubber for a new energy heavy-duty truck is provided, which comprises, by weight:

[0007] 13-17 parts of butadiene rubber, 30-35 parts of low molecular weight trans-butadiene-polyisoprene rubber, 30-40 parts of styrene-butadiene rubber, 35-40 parts of carbon black, 10-15 parts of modified white carbon black, 2-3 parts of vulcanizing agent, 3-10 parts of activator, 2-5 parts of antioxidant, 1-2 parts of accelerator, 1-2 parts of scorch retarder;

[0008] The modified white carbon black is obtained by modification with sulfaguanidine, active silica gel and dopamine.

[0009] Compared with the white carbon black modified by silane coupling agent and other substances in the prior art, the modified white carbon black used in the present application has high dispersibility in the rubber matrix, and can participate in the cross-linking reaction of the rubber matrix, increase the compatibility with the rubber matrix, and thus improve the mechanical properties, puncture resistance and tear resistance of the matrix.

[0010] Optionally, the molar content of butadiene units in the low molecular weight trans-butadiene-isoprene copolymer rubber is 5% to 70%, the molar content of isoprene units is 95% to 30%, the molar content of trans-1,4-structure is greater than 85%, and the weight average molecular weight is 5000 to 8000.

[0011] Optionally, the modification method of the modified white carbon black is:

[0012] S1: Add activated silica gel to the sulfaguanidine solution and stir evenly to obtain a modified solution, place white carbon black in the modified solution, stir for 30 min-60 min at room temperature, dry, roast, cool, and grind to a particle size of 40-50 nm to obtain an intermediate;

[0013] S2: placing the intermediate and dopamine in a buffer solution, treating at room temperature for 2-3 hours, washing and drying to obtain the modified silica.

[0014] In step S1, a modification liquid containing sulfaguanidine solution and active silica gel is used to modify silica, so that the surface of silica is coated with active silica gel containing sulfaguanidine. The sulfaguanidine can participate in the cross-linking reaction of the rubber matrix, so that silica can be evenly dispersed in the cross-linked network, thereby improving the mechanical and thermal properties of the tread rubber, avoiding the migration of silica due to long-term use, and improving the stability of the tread rubber. The active silica gel can form larger holes, which can absorb the noise and impact force during the operation of the tire, thereby reducing the noise of the tread rubber and improving the shock absorption performance.

[0015] At present, there is a scheme of modifying silica with dopamine to obtain polydopamine-modified silica (for example, patent CN104650419A). The polydopamine-modified silica can improve the mechanical strength of rubber. However, due to the limited specific surface area of ​​silica, the effect of polydopamine is limited. If the specific surface area is to be increased, the particle size of silica needs to be reduced. Although this method can increase the adhesion amount of polydopamine to a certain extent, firstly, since the particle size of silica itself is too small, it will increase its agglomeration in the rubber. Second, silica will migrate more easily during the use of the tire, reducing the durability of the tire. Third, it will increase the noise of the tire during operation.

[0016] Therefore, the present application further uses polydopamine for modification on the basis of the prepared intermediate, which is beneficial to the pores of the active silica gel performance to increase the specific surface area of ​​white carbon black, thereby increasing the adhesion amount of polydopamine, and will not increase the agglomeration of white carbon black. On the basis of improving the dispersibility of white carbon black, it works together with sulfaguanidine to reduce the migration of white carbon black, improve the durability of the tire, and achieve a synergistic improvement in the mechanical properties, impact resistance, noise, and shock absorption performance of the tire.

[0017] Optionally, the concentration of the sulfaguanidine solution is 0.1-0.2 mol / L, the weight ratio of the activated silica gel to the sulfaguanidine solution is 1:(10-15), and the weight ratio of the white carbon black to the modified liquid is 1:(20-30);

[0018] Preferably, the concentration of the sulfaguanidine solution is 0.2 mol / L, the weight ratio of the activated silica gel to the sulfaguanidine solution is 1:10, and the weight ratio of the white carbon black to the modified liquid is 1:20.

[0019] The above parameters can improve the coating of activated silica gel on silica and control the adhesion amount of sulfaguanidine on the surface of activated silica gel, thereby improving the dispersion of silica in the matrix and the bonding force with the matrix. Since sulfaguanidine itself carries more amino groups, the modified silica will also act as a cross-linking point, which can play a buffering role when the tire is impacted, thereby enhancing the impact resistance and shock absorption performance of the cross-linking network of the rubber matrix.

[0020] Optionally, the calcination temperature is 200-250°C and the calcination time is 3-4h;

[0021] Preferably, the calcination temperature is 250° C. and the calcination time is 3 hours.

[0022] The calcination time is related to the pore size of the active silica gel in the outer layer of the intermediate. The calcination temperature can make the pore size of the intermediate moderate, which is convenient for the subsequent formation of polydopamine on the pore surface and is beneficial for absorbing noise.

[0023] Optionally, the preparation method of the active silica gel is: calcining the silica gel at 300-350° C. for 4 hours, and then soaking it in a mixed solution of ethanol and water at room temperature for at least 6 hours.

[0024] Optionally, the buffer solution is prepared by dissolving a weak alkaline buffer in deionized water, adding a pH adjuster to adjust the pH to 8-9 to obtain a buffer solution, wherein the concentration of the weak alkaline buffer in the buffer solution is 5-10 mmol / L.

[0025] Optionally, the weak alkaline buffer is selected from tris(hydroxymethyl)aminomethane or barbital;

[0026] Preferably, the pH regulator is selected from an inorganic acid or an inorganic base, the inorganic acid is selected from one of hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and the inorganic base is selected from potassium hydroxide or sodium hydroxide.

[0027] Optionally, the weight ratio of the intermediate to dopamine is 1:(0.1-0.3), and the weight ratio of the intermediate to buffer solution is 1:(100-200).

[0028] The above parameters can adjust the amount of polydopamine on the surface of the intermediate, so as to obtain modified silica with the best dispersion performance. The modified silica obtained after the above modification not only improves its own dispersibility, but also can assist in improving the dispersibility of carbon black, so that the filler in the tread rubber can be evenly dispersed along the cross-linked network of the matrix, so that the wear resistance and anti-skid performance of the tire are improved.

[0029] Optionally, the tread rubber further comprises 10-15 parts of reinforcing resin, wherein the reinforcing resin is obtained by polymerizing cyclohexyl acetate allyl ester, monomer A and monomer B in a weight ratio of (1-2):1:(0.5-0.8), wherein the structural formula of monomer A is shown in formula (1):

[0030] Where n is selected from any integer between 1 and 3;

[0031] Monomer B is obtained by an addition reaction between a diacrylate monomer and sulfonamide.

[0032] The reinforcing resin added in the present application contains double bonds and some amino groups, so the reinforcing resin can form a cross-linked network by itself during the vulcanization process, which interpenetrates with the cross-linked network formed by the rubber, and can bond with the rubber to integrate into the cross-linked network of the rubber, thereby enhancing the bonding with the rubber.

[0033] The construction of the above two cross-linked networks can, firstly, increase the compatibility with the rubber substrate and improve the mechanical strength, grip and wear resistance of the tread rubber; secondly, in combination with modified silica, it can reflect and absorb vibration energy, so that it has sound insulation and vibration reduction functions in a wider frequency range, thereby significantly reducing the noise generated during tire operation; thirdly, due to the synergy of the chain segment length and various groups in the enhanced resin, the hysteresis loss of the rubber can be reduced, and the heat generation and rolling resistance of the tire can be reduced.

[0034] In the above-mentioned reinforced resin, the presence of monomer A can increase the chain length of the reinforced resin and improve the toughness of the above-mentioned cross-linked network. Allyl cyclohexyl acetate can introduce epoxy side chains. It has been verified by experiments that the introduction of the epoxy side chains can improve the compatibility with carbon black and white carbon black, thereby enabling carbon black and white carbon black to be evenly dispersed in the rubber system, thereby enhancing the mechanical properties and grip of the tread rubber. The monomer B obtained by the reaction of sulfaguanidine and diacrylate monomers has multiple double bonds and a small amount of amino groups, which can regulate the cross-linking point density and the chain length between the cross-linking points of the reinforced resin cross-linking network and the rubber cross-linking network, thereby effectively reducing the deformation and hysteresis loss of the tire and reducing heat generation. In addition, since sulfaguanidine contains benzene rings and sulfur-oxygen double bonds, the presence of benzene rings can enhance the strength of the cross-linked network and improve the wear resistance of the tread rubber. The presence of sulfur-oxygen double bonds can improve the affinity between the system and the vulcanizer, improve the processing performance and vulcanization uniformity of the tread rubber, thereby improving the performance consistency of the tread rubber.

[0035] The presence of the above-mentioned monomer A and diacrylate monomer makes the molecular chain of the reinforced resin contain more ester groups and ether groups, which can significantly improve the temperature resistance of the tread rubber, thereby broadening the use temperature range of the tread rubber. Even in the severe cold weather in winter and the high temperature in summer, it can still maintain high wear resistance, low heat generation, low noise and low rolling resistance, and can also play a role in damping and shock absorption, thereby improving the running stability of new energy heavy-duty trucks.

[0036] Optionally, the monomer A is selected from 1,3-propylene glycol diacetate (CAS No.: 24493-53-6), 3-(3-prop-2-enoyloxypropoxy)prop-2-enoic acid propyl ester (CAS No.: 1026700-18-4), trimer (1,3-propylene glycol) diacrylate (CAS No.: 68901-05-3)

[0037] Optionally, the weight ratio of the diacrylate monomer to sulfamethoxazole is (3-4):1.

[0038] The above weight ratio can improve the reaction efficiency of the double bonds of the diacrylate monomer and the amino groups in sulfonamide, thereby increasing the double bond content of monomer B. However, due to the steric effect of the amino groups in sulfonamide that reacted first, there are still some unreacted amino groups in monomer B. The presence of these amino groups does not affect the improvement of the overall performance of the tire. However, if the amount of diacrylate monomer added is too small, the number of amino groups in monomer B will increase, which will reduce the number of cross-linking points of the reinforced resin cross-linking network and the binding with the rubber cross-linking network, thereby reducing the overall performance of the tire.

[0039] Optionally, the diacrylate monomer is selected from at least one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate and tripropylene glycol diacrylate.

[0040] Optionally, the reaction conditions of the diacrylate monomer and sulfonamide are as follows: placing the diacrylate monomer and sulfonamide in a first solvent, adding a catalyst, and reacting at 40-70° C. for at least 4 hours to obtain.

[0041] Optionally, the catalyst is a lithium salt, and the lithium salt is selected from at least one of lithium iodide, lithium bromide, lithium chloride and lithium fluoride.

[0042] Optionally, the amount of the lithium salt added is 2-4% by weight of the sulfaguanidine.

[0043] Optionally, the first solvent is selected from at least one of a mixed solvent of isopropanol and water, a mixed solvent of diethylene glycol butyl ether and water, and a mixed solvent of toluene and water, and in the above mixed solvents, water accounts for 50-60wt%.

[0044] Optionally, the polymerization step of the reinforcing resin is:

[0045] S11: dissolving the allyl cyclohexyl acetate and monomer A in a second solvent, and polymerizing under the action of an initiator to obtain a solution containing an intermediate;

[0046] S12: adding monomer B to the solution containing the intermediate to polymerize, and obtaining the reinforced resin after separation.

[0047] Optionally, the second solvent is selected from at least one of chloroform, ethyl acetate and tetrahydrofuran.

[0048] Optionally, the reaction temperature of step S11 is 80-90° C., and the reaction time is 5-6 h.

[0049] Optionally, the reaction temperature of step S12 is 80-90° C., and the reaction time is 3-5 h.

[0050] According to another aspect of the present application, a method for preparing a tire tread rubber for a new energy heavy truck as described in any one of the above items is provided, comprising the following steps:

[0051] (1) mixing cis-1,4-butadiene rubber, low molecular weight trans-butadiene-polyisoprene rubber, styrene-butadiene rubber and modified white carbon black in one step, then adding carbon black, an activator, an antioxidant and a scorch retarder for two-step mixing and then discharging the rubber to obtain a mixed rubber;

[0052] (2) adding a vulcanizing agent and an accelerator to the mixed rubber and performing three-step mixing, and then cooling the mixed rubber to obtain the mixed rubber.

[0053] Optionally, the one-step mixing temperature is 60-80° C. and the time is 5-10 min;

[0054] The temperature of the two-step mixing is 80-90°C and the time is 5-10min;

[0055] The temperature of the three-step mixing is 50-70° C. and the time is 2-3 minutes.

[0056] According to another aspect of the present application, there is provided a use of the tire tread rubber for new energy heavy-duty trucks as described in any one of the above items in the preparation of tires for new energy heavy-duty trucks.

[0057] The beneficial effects of this application include but are not limited to:

[0058] 1. The tire prepared with the tire tread rubber for new energy heavy-duty trucks of the present application has improved mechanical properties, good wear resistance, puncture resistance, tear resistance, and impact resistance, and has good grip, and can be used for long-term use on harsh driving surfaces such as mountainous areas and mining areas.

[0059] 2. The modified white carbon black used in the tire tread rubber for new energy heavy-duty trucks of the present application not only has high dispersion performance in the rubber matrix, but also can improve the dispersion of carbon black, reduce its own migration, and improve the durability and temperature resistance of the tire.

[0060] 3. The tire tread rubber for new energy heavy-duty trucks of the present application has a modified silica outer layer coated with active silica gel with holes, which can absorb and reflect vibration energy during the operation of the tire, thereby improving the low noise and shock absorption of the tire prepared with the tread rubber.

[0061] 4. The tire tread rubber for new energy heavy-duty trucks of the present application adopts a ratio of butadiene rubber, low molecular weight trans-butadiene-polyisoprene and styrene-butadiene rubber that can synergistically improve various properties of the tire, as well as the temperature resistance and weather resistance of the tire. Reinforcing resin is added to the above-mentioned matrix to reduce the heat generation and rolling resistance of the tire. DETAILED DESCRIPTION

[0062] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0063] Unless otherwise specified, the raw materials in the examples and comparative examples of the present application were purchased through commercial channels.

[0064] Unless otherwise specified, the methods used in the examples and comparative examples of the present application are conventional methods in the prior art. The vulcanizing agent used in the following examples is sulfur, the activator is zinc oxide, the antioxidant is antioxidant RD, the accelerator is zinc dibutyl dithiocarbamate, the anti-scorch agent is anti-scorch agent CTP, the particle size of white carbon black before modification is 30 nm, and the carbon black is carbon black N330.

[0065] Example 1

[0066] The present embodiment relates to a tire tread rubber for new energy heavy trucks and a preparation method thereof. The tread rubber includes, by weight: 13 parts of butadiene rubber, 30 parts of low molecular weight trans-butadiene-polyisoprene rubber, 30 parts of styrene-butadiene rubber, 35 parts of carbon black, 10 parts of modified white carbon black, 2 parts of vulcanizing agent, 3 parts of activating agent, 2 parts of antioxidant, 1 part of accelerator, and 1 part of anti-scorch agent. The molar content of butadiene units in the low molecular weight trans-butadiene-polyisoprene rubber is 5%, the molar content of isoprene diene units is 95%, the molar content of trans-1,4-structure is greater than 85%, and the weight average molecular weight is 8000; the modification method of modified white carbon black is:

[0067] S1: Calcinate silica gel at 300°C for 4 hours, then immerse it in a mixed solution of ethanol and water at room temperature for 8 hours to obtain active silica gel, add active silica gel to a 0.1 mol / L sulfaguanidine solution and stir evenly to obtain a modified solution, the weight ratio of active silica gel to sulfaguanidine solution is 1:15, place white carbon black in the modified solution, the weight ratio of white carbon black to the modified solution is 1:30, stir at room temperature for 30 minutes, dry at 30°C for 8 hours, calcine at 200°C for 4 hours, and grind to a particle size of 40 nm after cooling to obtain an intermediate;

[0068] S2: Barbiturate was dissolved in deionized water, and a pH regulator was added to adjust the pH to 8 to obtain a buffer solution, wherein the concentration of barbiturate in the buffer solution was 5 mmol / L, and the intermediate and dopamine were placed in the buffer solution, wherein the weight ratio of the intermediate to dopamine was 1:0.1, and the weight ratio of the intermediate to the buffer solution was 1:100, and the mixture was treated at room temperature for 3 h, washed with deionized water, and dried at 60°C for 8 h to obtain modified silica.

[0069] The preparation method of tire tread rubber comprises the following steps:

[0070] (1) mixing cis-1,4-butadiene rubber, low molecular weight trans-butadiene-polyisoprene rubber, styrene-butadiene rubber and modified white carbon black in one step at 80° C. for 5 min, then adding carbon black, activator, antioxidant and anti-scorch agent, mixing in two steps at 90° C. for 5 min, and then discharging to obtain a mixed rubber;

[0071] (2) Add vulcanizing agent and accelerator to the mixed rubber and mix them in three steps at 70°C for 2 minutes. After the rubber is discharged and cooled, tread rubber 1# is obtained.

[0072] Example 2

[0073] The present embodiment relates to a tire tread rubber for new energy heavy trucks and a preparation method thereof. The tread rubber includes, by weight: 17 parts of cis-butadiene rubber, 35 parts of low molecular weight trans-butadiene-polyisoprene rubber, 40 parts of styrene-butadiene rubber, 40 parts of carbon black, 15 parts of modified white carbon black, 3 parts of vulcanizing agent, 5 parts of activator, 5 parts of antioxidant, 2 parts of accelerator, and 2 parts of scorch retarder. The molar content of butadiene units in the low molecular weight trans-butadiene-polyisoprene rubber is 30%, the molar content of isoprene diene units is 70%, the molar content of trans-1,4-structure is greater than 95%, and the weight average molecular weight is 5000. The modification method of modified white carbon black is:

[0074] S1: Calcinate silica gel at 350°C for 4 hours, then immerse it in a mixed solution of ethanol and water at room temperature for 6 hours to obtain active silica gel, add active silica gel to a 0.2 mol / L sulfaguanidine solution and stir evenly to obtain a modified solution, the weight ratio of active silica gel to sulfaguanidine solution is 1:10, place white carbon black in the modified solution, the weight ratio of white carbon black to the modified solution is 1:20, stir at room temperature for 60 minutes, dry at 30°C for 8 hours, and calcine at 250°C for 3 hours. After cooling, grind to a particle size of 50 nm to obtain an intermediate;

[0075] S2: Dissolve tris(hydroxymethyl)aminomethane in deionized water, add a pH adjuster to adjust the pH to 9 to obtain a buffer solution, the concentration of tris(hydroxymethyl)aminomethane in the buffer solution is 10 mmol / L, place the intermediate and dopamine in the buffer solution, the weight ratio of the intermediate to dopamine is 1:0.3, the weight ratio of the intermediate to the buffer solution is 1:200, treat at room temperature for 2 hours, wash with deionized water, and dry at 50°C for 8 hours to obtain modified silica.

[0076] The preparation method of tire tread rubber comprises the following steps:

[0077] (1) mixing butadiene rubber, low molecular weight trans-butadiene-polyisoprene rubber, styrene-butadiene rubber and modified white carbon black in one step at 60° C. for 10 min, then adding carbon black, activator, antioxidant and anti-scorch agent, mixing in two steps at 80° C. for 10 min, and then discharging to obtain a mixed rubber;

[0078] (2) Add vulcanizing agent and accelerator to the mixed rubber and mix them in three steps at 50°C for 3 minutes. After the rubber is discharged and cooled, tread rubber 2# is obtained.

[0079] Example 3

[0080] The difference between this embodiment and embodiment 2 is that the weight ratio of the activated silica gel to the sulfamethoxazole solution in step S1 is 1:8, and the rest is the same as embodiment 2, to obtain tread rubber 3#.

[0081] Example 4

[0082] The difference between this embodiment and embodiment 2 is that the weight ratio of white carbon black to the modifying liquid in step S1 is 1:15, and the rest is the same as embodiment 2, to obtain tread rubber 4#.

[0083] Example 5

[0084] The difference between this embodiment and embodiment 2 is that step S1 is calcined at 300° C. for 4 hours, and the rest is the same as embodiment 2, to obtain tread rubber 5#.

[0085] Example 6

[0086] The difference between this embodiment and embodiment 2 is that the weight ratio of the intermediate to dopamine in step S2 is 1:0.4, and the rest is the same as embodiment 2, to obtain tread rubber 6#.

[0087] Example 7

[0088] The difference between this embodiment and embodiment 2 is that the modification method of modified white carbon black is different, specifically:

[0089] S1: calcine silica gel at 350°C for 4 hours, then soak it in a mixed solution of ethanol and water at room temperature for 6 hours to obtain active silica gel, add active silica gel to a 0.2 mol / L sulfaguanidine solution and stir evenly to obtain a modified solution, the weight ratio of active silica gel to sulfaguanidine solution is 1:10;

[0090] S2: dissolving tris(hydroxymethyl)aminomethane in deionized water, adding a pH adjuster to adjust the pH to 9 to obtain a buffer solution, wherein the concentration of tris(hydroxymethyl)aminomethane in the buffer solution is 10 mmol / L;

[0091] S3: The modified liquid and the buffer solution are mixed in a weight ratio of 1:1, and then white carbon black is added, and the weight ratio of white carbon black to the modified liquid is 1:20. The mixture is placed at room temperature for 1.5 hours, dried at 30°C for 8 hours, and then calcined at 250°C for 3 hours. After cooling, the mixture is ground to a particle size of 50 nm to obtain modified white carbon black.

[0092] The rest is the same as in Example 2, and tread rubber 7# is obtained.

[0093] Example 8

[0094] The difference between this embodiment and embodiment 2 is that it further comprises 10 parts of reinforcing resin, wherein the preparation steps of the reinforcing resin are as follows:

[0095] S0: 1,6-hexanediol diacrylate and sulfaguanidine in a weight ratio of 3:1 are placed in a mixed solvent of isopropanol and water (the proportion of water is 50wt%), lithium iodide catalyst is added, and the amount of the catalyst added is 2% of the weight of sulfaguanidine, and the reaction is carried out at 70°C for 4h, and then filtered, washed, and dried to obtain monomer B;

[0096] S11: dissolving allyl cyclohexyloxyacetate and trimer (1,3-propylene glycol) diacrylate in a weight ratio of 2:1 in a mixed solvent of chloroform and tetrahydrofuran (the weight ratio of chloroform and tetrahydrofuran is 1:1), adding 2% azobisisobutyronitrile based on the weight of trimer (1,3-propylene glycol) diacrylate, and polymerizing at 80° C. for 5 h to obtain a solution containing an intermediate;

[0097] S12: adding monomer B to the solution containing the intermediate, the weight ratio of trimer (1,3-propylene glycol) diacrylate to monomer B is 1:0.8, polymerizing at 90° C. for 3 h, and obtaining a reinforced resin after rotary evaporation, washing, and column chromatography separation.

[0098] In the preparation of tire tread rubber, reinforcing resin, butadiene rubber, low molecular weight trans-butadiene-polyisoprene rubber, styrene-butadiene rubber and modified white carbon black were mixed in one step at 80° C. for 5 min, and the rest was the same as in Example 2 to obtain tread rubber 8#.

[0099] Example 9

[0100] The difference between this embodiment and embodiment 2 is that it further comprises 15 parts of reinforcing resin, wherein the preparation steps of the reinforcing resin are as follows:

[0101] The preparation steps of the reinforced resin are:

[0102] S0: dipropylene glycol diacrylate and sulfaguanidine in a weight ratio of 4:1 are placed in a mixed solvent of diethylene glycol butyl ether and water (the proportion of water is 60wt%), lithium bromide catalyst is added, and the amount of the catalyst added is 4% of the weight of sulfaguanidine, and the reaction is carried out at 40°C for 6h, and then filtered, washed, and dried to obtain monomer B;

[0103] S1: dissolving allyl cyclohexyl acetate and 1,3-propylene glycol diacetate in a weight ratio of 1:1 in a mixed solvent of chloroform and tetrahydrofuran (the weight ratio of chloroform and tetrahydrofuran is 1:1), adding 2% azobisisobutyronitrile based on the weight of 1,3-propylene glycol diacetate, and polymerizing at 90° C. for 5 h to obtain a solution containing an intermediate;

[0104] S2: adding monomer B to the solution containing the intermediate, the weight ratio of 1,3-propylene glycol diacetate to monomer B is 1:0.5, polymerizing at 80°C for 5h, and obtaining a reinforced resin after rotary evaporation, washing, and column chromatography separation.

[0105] In the preparation of tire tread rubber, reinforcing resin, butadiene rubber, low molecular weight trans-butadiene-polyisoprene rubber, styrene-butadiene rubber and modified white carbon black were mixed in one step at 80° C. for 5 min, and the rest was the same as in Example 2 to obtain tread rubber 9#.

[0106] Example 10

[0107] The difference between this embodiment and embodiment 8 is that the weight ratio of trimer (1,3-propylene glycol) diacrylate and monomer B is 1:1, and the rest is the same as embodiment 8, and tread rubber 10# is obtained.

[0108] Embodiment 11

[0109] The difference between this embodiment and embodiment 8 is that the weight ratio of 1,6-hexanediol diacrylate to sulfaguanidine is 2:1, and the rest is the same as embodiment 8, to obtain tread rubber 11#.

[0110] Comparative Example 1

[0111] The difference between this comparative example and Example 2 is that a silane coupling agent is used to modify silica, and silica and water are mixed to obtain a silica-water suspension, wherein the weight of silica accounts for 5% of the total weight of the suspension, and 10% of the weight of silica is first added to the silica suspension as a silane coupling agent, ultrasonically modified for 3 hours, washed with deionized water, and dried at 60°C for 8 hours to obtain modified silica.

[0112] The rest is the same as in Example 2, and a comparative tread rubber D1# is obtained.

[0113] Comparative Example 2

[0114] The difference between this comparative example and Example 2 is that the added amount of modified white carbon black is 5 parts, and the rest is the same as Example 2, to obtain comparative tread rubber D2#.

[0115] Comparative Example 3

[0116] The difference between this comparative example and Example 2 is that the added amount of modified white carbon black is 20 parts, and the rest is the same as Example 2, to obtain comparative tread rubber D3#.

[0117] Test Example 1

[0118] The tread rubbers prepared in the above embodiments and comparative examples were subjected to the following experimental tests, and the test results are shown in Table 1:

[0119] 1. Mechanical properties test: tensile strength and elongation at break were tested in accordance with GB / T 528-2009.

[0120] 2. Wear resistance test: Wear resistance test is carried out in accordance with GB / T1689-1998 Determination of wear resistance of vulcanized rubber. The lower the Akron wear value, the better the wear resistance of the tread rubber.

[0121] 3. Hot air aging tensile aging coefficient: tested in accordance with GB / T 3512-2014 standard. The larger the hot air aging tensile aging coefficient, the better its resistance to heat and oxygen aging.

[0122] 4. Compression heat generation: A rubber dynamic compression heat generation instrument is used to test the compression heat generation of the above tread rubber.

[0123] Table 1

[0124]

[0125] According to the data in Table 1, the addition of modified silica to the tread rubber of the present application enables the silica to be evenly dispersed in the rubber matrix, so the tread rubber has high mechanical properties, good wear resistance and aging resistance, and low heat generation, and the above properties can be further improved by adding reinforcing resin.

[0126] Test Example 2

[0127] According to the same truck tire preparation process, the finished tires obtained in the above embodiments and comparative examples were processed to prepare tires, and the following tests were performed on the tires. The results are shown in Table 2.

[0128] 1. Noise reduction performance: The noise reduction test is carried out in accordance with GB / T32789 1016 "Tire Noise Test Method - Drum Method". After the test, the tires are drummed for 48 hours under the same conditions, left to stand for 12 hours, and then the noise test is carried out again. The lower the noise value, the better the tread rubber performance.

[0129] 2. Wet skid resistance: Each test tire is installed on an all-wheel drive heavy-duty truck, and the braking distance is tested from the braking start position at a first speed of 50km / h on a wet cement road. The smaller the braking distance value, the better the anti-wet skid resistance and grip of the tread rubber.

[0130] 3. Rolling resistance coefficient: Tire rolling resistance is the energy loss per unit driving distance. The tire rolling resistance coefficient is the ratio of the rolling resistance expressed in Newtons to the tire load expressed in Newtons. The smaller the rolling resistance coefficient, the smaller the tire rolling resistance.

[0131] 4. RCC-I rubber dynamic cutting tester is used for testing. The sample rotation speed is 720r / min, the cutting frequency is 120 times / min, the cutting time is 20min, and the cutting amount is detected. The smaller the cutting amount, the higher the cut resistance and puncture resistance of the tire.

[0132] Table 2

[0133]

[0134]

[0135] According to the data in Table 2, the tread rubber of the present application can significantly reduce the noise of the tire, improve the running stability of the new energy heavy-duty truck, improve the grip of the tire while reducing the rolling resistance, improve the driving stability of the new energy heavy-duty truck on harsh ground, and at the same time improve the puncture resistance of the tire and extend the service life of the tire.

[0136] The above are only embodiments of the present application. The protection scope of the present application is not limited by these specific embodiments, but is determined by the claims of the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the technical ideas and principles of the present application should be included in the protection scope of the present application.

Claims

1. A tire tread rubber for a new energy heavy truck, characterized in that: By weight, it includes: 13-17 parts of butadiene rubber, 30-35 parts of low molecular weight trans-butadiene-polyisoprene rubber, 30-40 parts of styrene-butadiene rubber, 35-40 parts of carbon black, 10-15 parts of modified white carbon black, 2-3 parts of vulcanizing agent, 3-5 parts of activator, 2-5 parts of antioxidant, 1-2 parts of accelerator, 1-2 parts of scorch retarder; The modified white carbon black is obtained by modification with sulfaguanidine, activated silica gel and dopamine; The modification method of the modified white carbon black is: S1: Add active silica gel to the sulfaguanidine solution and stir evenly to obtain a modified solution, place white carbon black in the modified solution, stir for 30 min-60 min at room temperature, dry, roast, cool and grind to a particle size of 40-50 nm to obtain an intermediate, the concentration of the sulfaguanidine solution is 0.1-0.2 mol / L, the weight ratio of the active silica gel to the sulfaguanidine solution is 1: (10-15), the weight ratio of the white carbon black to the modified solution is 1: (20-30), and the preparation method of the active silica gel is: roasting the silica gel at 300-350° C. for 4 h, and then soaking it in a mixed solution of ethanol and water at room temperature for at least 6 h to obtain an intermediate; S2: placing the intermediate and dopamine in a buffer solution, treating at room temperature for 2-3 hours, washing and drying to obtain the modified silica, the weight ratio of the intermediate to dopamine is 1: (0.1-0.3), and the weight ratio of the intermediate to the buffer solution is 1: (100-200).

2. The tire tread rubber for new energy heavy trucks according to claim 1, characterized in that: The concentration of the sulfaguanidine solution is 0.2 mol / L, the weight ratio of the activated silica gel to the sulfaguanidine solution is 1:10, and the weight ratio of the white carbon black to the modified liquid is 1:

20.

3. The tire tread rubber for new energy heavy trucks according to claim 1, characterized in that: The calcination temperature is 200-250° C., and the calcination time is 3-4 hours.

4. The tire tread rubber for new energy heavy trucks according to claim 3, characterized in that: The calcination temperature is 250° C. and the calcination time is 3 hours.

5. The tire tread rubber for new energy heavy trucks according to claim 1, characterized in that: The preparation method of the buffer solution is: dissolving a weak alkaline buffer in deionized water, adding a pH adjuster to adjust the pH to 8-9 to obtain a buffer solution, wherein the concentration of the weak alkaline buffer in the buffer solution is 5-10 mmol / L.

6. The tire tread rubber for new energy heavy trucks according to claim 5, characterized in that: The weak alkaline buffer is selected from tris(hydroxymethyl)aminomethane or barbital.

7. The tire tread rubber for new energy heavy trucks according to claim 6, characterized in that: The pH regulator is selected from an inorganic acid or an inorganic base, the inorganic acid is selected from one of hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and the inorganic base is selected from potassium hydroxide or sodium hydroxide.

8. The method for preparing a tire tread rubber for a new energy heavy truck according to any one of claims 1 to 7, characterized in that: The steps include: (1) mixing butadiene rubber, low molecular weight trans-butadiene-polyisoprene rubber, styrene-butadiene rubber and modified white carbon black in one step, then adding carbon black, activator, antioxidant and anti-scorch agent for two-step mixing and then discharging to obtain a mixed rubber; (2) Adding a vulcanizing agent and an accelerator to the mixed rubber and performing three-step mixing, and then cooling the mixed rubber to obtain the mixed rubber.

9. Use of the tire tread rubber for new energy heavy-duty trucks according to any one of claims 1 to 7 in preparing tires for new energy heavy-duty trucks.

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