Tread rubber for heat-resistant tire tread and preparation method of tread rubber

Abstract

The invention provides a tread rubber for a heat-resistant tire tread and a preparation method thereof, and belongs to the technical field of tire tread rubber materials, the tread rubber for the heat-resistant tire tread is prepared from the following raw materials: 100 parts of natural rubber, 45-55 parts of acrylate grafted styrene-butadiene rubber, 35-45 parts of carbon black, 8-12 parts of composite modified zinc oxide, 4-6 parts of stearic acid, and 2-4 parts of an anti-aging agent. The composite modified zinc oxide is prepared by carrying out composite modification on zinc oxide through ceric ammonium nitrate and rice hull ash. The tread rubber for the heat-resistant tire tread, provided by the invention, has relatively high high-temperature resistance, so that a tire can keep relatively high mechanical strength at a high temperature, and the driving safety at the high temperature and the long-term use of the tire are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of tire tread rubber materials, and particularly relates to a tread rubber for a heat-resistant tire and a preparation method thereof. Background Art

[0002] The surface temperature in my country is relatively high in summer, especially in high-speed long-distance transportation scenarios. The speed is fast, the load is heavy, and the driving time is long. The tire tread temperature can reach 80-100℃, which will accelerate rubber aging and the mechanical strength of the tread rubber will drop sharply, resulting in tread tearing and a significantly increased risk of tire blowout. This has become the main cause of early tire damage and traffic accidents in long-distance freight transportation in summer. Therefore, the high-temperature stability of tires is crucial to driving safety and tire body service life.

[0003] Traditional rubber materials such as natural rubber or styrene-butadiene rubber are prone to thermal oxidative aging when the temperature exceeds 80°C, resulting in molecular chain breakage, decreased cross-linking density, and a sharp decline in mechanical properties, manifested as a decrease in tensile strength of more than 30%. Especially under continuous high-load operation, heat accumulation will be aggravated. The current industry generally adopts the addition of antioxidants or fine-tuning of the vulcanization system to improve heat resistance. Although the existing heat-resistant formula can partially alleviate thermal degradation, the effect is limited and it cannot achieve ideal high-temperature resistance. Under long-term high temperature and dynamic stress, the cross-linking network of the tread rubber is still prone to irreversible damage, causing the rubber to harden and become brittle. At the same time, high temperature will significantly reduce the fatigue life and dynamic modulus of the rubber, affecting the handling stability and driving safety of the tire.

[0004] As domestic and international standards for high-temperature aging tests of tires become increasingly stringent, the high-temperature resistance of existing colloid materials is difficult to meet the safety threshold for long-term use. There is an urgent need to develop a heat-resistant tread rubber material to ensure driving safety under high temperatures and long-term use of tires. Summary of the Invention

[0005] In order to solve the problems existing in the background technology, the present invention provides a heat-resistant tire tread rubber and a preparation method thereof, which has high high temperature resistance and can enable the tire to maintain high mechanical strength at high temperatures, thereby ensuring driving safety at high temperatures and long-term use of the tire.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A heat-resistant tire tread rubber comprises the following raw materials, calculated by weight: 100 parts of natural rubber, 45-55 parts of acrylate-grafted styrene-butadiene rubber, 35-45 parts of carbon black, 8-12 parts of composite modified zinc oxide, 4-6 parts of stearic acid, 2-4 parts of antioxidant, 3-5 parts of sulfur, and 1-3 parts of accelerator;

[0008] The composite modified zinc oxide is prepared by composite modification of zinc oxide with ammonium cerium nitrate and rice husk ash.

[0009] Further, the preparation of acrylate grafted styrene butadiene rubber includes the following contents:

[0010] A1. The styrene-butadiene rubber latex is diluted with a diluent and emulsified with an emulsifier to obtain a styrene-butadiene rubber emulsion;

[0011] A2. Add an acrylate monomer and an initiator to the styrene-butadiene rubber emulsion in step A1 to carry out a grafting reaction to obtain an acrylate-grafted styrene-butadiene rubber.

[0012] Furthermore, the preparation of acrylate-grafted styrene-butadiene rubber includes the following:

[0013] A1. The styrene-butadiene rubber latex was diluted with water, sodium lauryl sulfate was added, and stirred under nitrogen to obtain a styrene-butadiene rubber emulsion;

[0014] A2. Add acrylate monomer and dibenzoyl peroxide to the styrene-butadiene rubber emulsion in step A1, and carry out grafting reaction at 40-60 ° C for 6-10h. After the reaction, demulsification, centrifugation and drying are carried out in sequence to obtain acrylate-grafted styrene-butadiene rubber.

[0015] Furthermore, in step A1, the mass ratio of water to styrene-butadiene rubber latex is 8-12:1, and the amount of sodium lauryl sulfate added is 3-10% of the mass of the styrene-butadiene rubber latex.

[0016] Furthermore, in step A2, the acrylic acid ester monomer is one or a mixture of two or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate and butyl methacrylate.

[0017] Furthermore, in step A2, the mass ratio of the styrene-butadiene rubber emulsion to the acrylic ester monomer is 10:4-6, and the amount of dibenzoyl peroxide added is 0.5-2% of the mass of the acrylic ester monomer.

[0018] Furthermore, the preparation of the composite modified zinc oxide includes the following steps:

[0019] B1. Calcine the rice husk ash at 500-600 ° C for 2-4h and cool to room temperature to obtain activated rice husk ash powder for later use;

[0020] B2 30 parts of dry zinc oxide and 3-8 parts of cerium ammonium nitrate were mixed, added to 250-350 parts of N, N- dimethylformamide, added base to adjust the pH to 9-10, heated to 60-70 ℃, stirred for 0.5-1.5h to obtain a pretreatment solution;

[0021] B3. The solution was cooled to 35-45 ° C, 12-18 parts of activated rice husk ash powder was added to the pretreated solution, stirred for 3-5 hours, filtered, vacuum dried, and sieved through 300-500 mesh to obtain a composite modified zinc oxide.

[0022] Furthermore, the antioxidant is one of antioxidant RD and antioxidant 4020, or a mixture of two or more thereof.

[0023] Furthermore, the accelerator is one of benzothiazole disulfide and N-cyclohexyl-2-benzothiazole sulfenamide, or a mixture of the two.

[0024] A method for preparing a heat-resistant tire tread surface rubber, used for preparing the heat-resistant tire tread surface rubber described in the above scheme, comprising the following steps:

[0025] S1. The natural rubber and acrylate grafted styrene butadiene rubber were masticated, and then the masticated rubber and 30-40% by mass of carbon black were put into an internal mixer for internal mixing, mixing to 110-120 ℃, discharge glue to obtain carbon black plastic;

[0026] S2. The carbon black plastic and the remaining carbon black, composite modified zinc oxide, antioxidant and stearic acid were mixed in an internal mixer and mixed to 125-130 ° C, drained to obtain a masterbatch;

[0027] S3. The mixed masterbatch, sulfur and accelerator are put into an internal mixer for mixing, mixing to 105-110°C, and draining to obtain the heat-resistant tire tread surface rubber.

[0028] This application has the following beneficial effects:

[0029] 1. The present invention provides a heat-resistant tire tread surface rubber and a preparation method thereof. The prepared heat-resistant tire tread surface rubber has high high-temperature resistance, can enable the tire to maintain high mechanical strength at high temperatures, and can ensure driving safety at high temperatures and long-term use of the tire.

[0030] 2. In order to improve the thermal stability of the tread rubber, the present invention adopts acrylate grafted styrene-butadiene rubber on the one hand. After grafting, the interaction force between the rubber molecular chains can be improved, the thermal stability of the rubber can be increased, and the rubber is not easily softened, deformed and degraded in a high temperature environment, maintaining good physical and mechanical properties. At the same time, it can cooperate with the antioxidant to inhibit the process of thermal oxidative aging and avoid the antioxidant from migrating, volatilizing or being consumed under the coupling of continuous high temperature and dynamic stress; on the other hand, through composite modified zinc oxide, the surface friction and hysteresis effect can be reduced, and it reacts with the rubber molecules to form a network structure during the mixing and vulcanization process, constructing a more stable cross-linked network, reducing the insufficient thermal stability of the polysulfide bonds formed in the vulcanization system at high temperature, avoiding the occurrence of breakage rearrangement and the decrease of cross-linking density, thereby effectively improving the stability of the high-temperature cross-linked network, effectively inhibiting thermal oxidative aging and maintaining excellent dynamic mechanical properties. DETAILED DESCRIPTION

[0031] The present application is further described in detail below with reference to the embodiments.

[0032] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0033] Example 1

[0034] A heat-resistant tire tread rubber is prepared from the following raw materials: 100 parts of natural rubber, 50 parts of acrylate-grafted styrene-butadiene rubber, 40 parts of carbon black, 10 parts of composite modified zinc oxide, 5 parts of stearic acid, 3 parts of antioxidant, 4 parts of sulfur, and 2 parts of accelerator, wherein the antioxidant is antioxidant RD and the accelerator is benzothiazole disulfide. The specific preparation process includes the following steps:

[0035] S1. The natural rubber and acrylate grafted styrene butadiene rubber were masticated, and then the masticated rubber and 35% by mass of carbon black were put into an internal mixer for internal mixing, mixing to 105 ° C, draining, to obtain a carbon black plastic;

[0036] S2. The carbon black plastic and the remaining carbon black, composite modified zinc oxide, antioxidant and stearic acid were mixed in an internal mixer and mixed to 125 ° C, discharged to obtain a mixed masterbatch;

[0037] S3. The mixed masterbatch, sulfur and accelerator are put into an internal mixer for mixing, mixing to 105°C, and draining to obtain the heat-resistant tire tread surface rubber.

[0038] The preparation process of acrylate grafted styrene butadiene rubber includes the following contents:

[0039] A1. Dilute styrene-butadiene rubber latex with water, add sodium lauryl sulfate, and stir under nitrogen to obtain a styrene-butadiene rubber latex. The mass ratio of water to styrene-butadiene rubber latex is 10:1, and the amount of sodium lauryl sulfate added is 5% of the mass of the styrene-butadiene rubber latex.

[0040] A2. Add an acrylate monomer and dibenzoyl peroxide to the styrene-butadiene rubber emulsion prepared in step A1, and conduct a grafting reaction at 50°C for 8 hours. After the reaction, demulsify, centrifuge, and dry to obtain an acrylate-grafted styrene-butadiene rubber. The acrylate monomer is methyl methacrylate, the mass ratio of the styrene-butadiene rubber emulsion to the acrylate monomer is 10:5, and the amount of dibenzoyl peroxide added is 1% of the mass of the acrylate monomer.

[0041] The preparation process of composite modified zinc oxide includes the following:

[0042] B1. Calcine the rice husk ash at 550°C for 3h and cool to room temperature to obtain activated rice husk ash powder for later use.

[0043] B2 30 parts of dry zinc oxide and 5 parts of cerium ammonium nitrate were mixed, added to 300 parts of N, N- dimethylformamide, added base to adjust the pH to 9-10, heated to 65 ° C, stirred for 1h to obtain a pretreatment solution;

[0044] B3. The solution was cooled to 40°C, 15 parts of activated rice husk ash powder was added to the pretreated solution, stirred for 4 hours, filtered, vacuum dried, and sieved through 400 mesh to obtain a composite modified zinc oxide.

[0045] Example 2

[0046] A heat-resistant tire tread rubber is prepared from the following raw materials: 100 parts of natural rubber, 45 parts of acrylate-grafted styrene-butadiene rubber, 35 parts of carbon black, 8 parts of composite modified zinc oxide, 4 parts of stearic acid, 2 parts of antioxidant, 3 parts of sulfur, and 1 part of accelerator, wherein the antioxidant is antioxidant 4020 and the accelerator is N-cyclohexyl-2-benzothiazolesulfenamide. The specific preparation process comprises the following steps:

[0047] S1. The natural rubber and acrylate grafted styrene butadiene rubber were masticated, and then the masticated rubber and 30% by mass of carbon black were put into an internal mixer for internal mixing, mixing to 110 ° C, draining, to obtain a carbon black plastic;

[0048] S2. The carbon black plastic and the remaining carbon black, composite modified zinc oxide, antioxidant and stearic acid were mixed in an internal mixer and mixed to 130 ° C, discharged to obtain a mixed masterbatch;

[0049] S3. The mixed masterbatch, sulfur and accelerator are put into an internal mixer for mixing, mixing to 110°C, and draining to obtain the heat-resistant tire tread surface rubber.

[0050] The preparation process of acrylate grafted styrene butadiene rubber includes the following contents:

[0051] A1. Dilute styrene-butadiene rubber latex with water, add sodium lauryl sulfate, and stir under nitrogen to obtain a styrene-butadiene rubber latex. The mass ratio of water to styrene-butadiene rubber latex is 8:1, and the amount of sodium lauryl sulfate added is 3% of the mass of the styrene-butadiene rubber latex.

[0052] A2. Add an acrylate monomer and dibenzoyl peroxide to the styrene-butadiene rubber emulsion prepared in step A1, and conduct a grafting reaction at 40°C for 10 hours. After the reaction, demulsify, centrifuge, and dry the mixture to obtain an acrylate-grafted styrene-butadiene rubber. The acrylate monomer is ethyl methacrylate, the mass ratio of the styrene-butadiene rubber emulsion to the acrylate monomer is 10:4, and the amount of dibenzoyl peroxide added is 0.5% of the mass of the acrylate monomer.

[0053] The preparation process of composite modified zinc oxide includes the following:

[0054] B1. Calcine the rice husk ash at 500°C for 4h and cool to room temperature to obtain activated rice husk ash powder for later use.

[0055] B2 30 parts of dry zinc oxide and 3 parts of cerium ammonium nitrate were mixed, added 250 parts of N, N- dimethylformamide, added base to adjust the pH to 9-10, heated to 60 ℃, stirred for 1.5h to obtain a pretreatment solution;

[0056] B3. The solution was cooled to 35°C, 12 parts of activated rice husk ash powder was added to the pretreated solution, stirred for 5 hours, filtered, vacuum dried, and sieved through 300 mesh to obtain a composite modified zinc oxide.

[0057] Example 3

[0058] A heat-resistant tire tread rubber is prepared from the following raw materials: 100 parts of natural rubber, 55 parts of acrylate-grafted styrene-butadiene rubber, 45 parts of carbon black, 12 parts of composite modified zinc oxide, 6 parts of stearic acid, 4 parts of an antioxidant, 5 parts of sulfur, and 3 parts of an accelerator, wherein the antioxidant is antioxidant RD and the accelerator is N-cyclohexyl-2-benzothiazolesulfenamide. The specific preparation process comprises the following steps:

[0059] S1. The natural rubber and acrylate grafted styrene butadiene rubber were masticated, and then the masticated rubber and 40% by mass of carbon black were put into an internal mixer for internal mixing, mixing to 120 ° C, draining, to obtain carbon black plastic;

[0060] S2. The carbon black plastic and the remaining carbon black, composite modified zinc oxide, antioxidant and stearic acid were mixed in an internal mixer and mixed to 125 ° C, discharged to obtain a mixed masterbatch;

[0061] S3. The mixed masterbatch, sulfur and accelerator are put into an internal mixer for mixing, mixing to 105°C, and draining to obtain the heat-resistant tire tread surface rubber.

[0062] The preparation process of acrylate grafted styrene butadiene rubber includes the following contents:

[0063] A1. Dilute styrene-butadiene rubber latex with water, add sodium lauryl sulfate, and stir under nitrogen to obtain a styrene-butadiene rubber latex. The mass ratio of water to styrene-butadiene rubber latex is 12:1, and the amount of sodium lauryl sulfate added is 10% of the mass of the styrene-butadiene rubber latex.

[0064] A2. Add an acrylate monomer and dibenzoyl peroxide to the styrene-butadiene rubber emulsion prepared in step A1, and conduct a grafting reaction at 60°C for 6 hours. After the reaction, demulsify, centrifuge, and dry the mixture to obtain an acrylate-grafted styrene-butadiene rubber. The acrylate monomer is propyl methacrylate, the mass ratio of the styrene-butadiene rubber emulsion to the acrylate monomer is 10:6, and the amount of dibenzoyl peroxide added is 2% of the mass of the acrylate monomer.

[0065] The preparation process of composite modified zinc oxide includes the following:

[0066] B1. Calcine the rice husk ash at 600°C for 2h and cool to room temperature to obtain activated rice husk ash powder for later use.

[0067] B2 30 parts of dry zinc oxide and 8 parts of cerium ammonium nitrate were mixed, added 350 parts of N, N- dimethylformamide, added base to adjust the pH to 9-10, heated to 70 ℃, stirred for 0.5h to obtain a pretreatment solution;

[0068] B3. The solution was cooled to 45°C, 18 parts of activated rice husk ash powder was added to the pretreated solution, stirred for 3 hours, filtered, vacuum dried, and sieved through 500 mesh to obtain a composite modified zinc oxide.

[0069] Comparative Example 1

[0070] The only difference between this comparative example and Example 1 is that in the raw material of the surface rubber for the heat-resistant tire tread, the styrene-butadiene rubber is not grafted with acrylate, that is, the acrylate-grafted styrene-butadiene rubber is replaced with styrene-butadiene rubber, specifically as follows:

[0071] A surface rubber for heat-resistant tire treads is prepared from the following raw materials: 100 parts of natural rubber, 50 parts of styrene-butadiene rubber, 40 parts of carbon black, 10 parts of composite modified zinc oxide, 5 parts of stearic acid, 3 parts of an antioxidant, 4 parts of sulfur, and 2 parts of an accelerator, wherein the antioxidant is antioxidant RD and the accelerator is benzothiazole disulfide.

[0072] Comparative Example 2

[0073] The only difference between this comparative example and Example 1 is that in the raw material of the heat-resistant tire tread rubber, zinc oxide is not compound-modified, that is, the compound-modified zinc oxide is replaced by zinc oxide, specifically as follows:

[0074] A surface rubber for heat-resistant tire treads is prepared from the following raw materials: 100 parts of natural rubber, 50 parts of acrylate-grafted styrene-butadiene rubber, 40 parts of carbon black, 10 parts of zinc oxide, 5 parts of stearic acid, 3 parts of an antioxidant, 4 parts of sulfur, and 2 parts of an accelerator, wherein the antioxidant is antioxidant RD and the accelerator is benzothiazole disulfide.

[0075] Comparative Example 3

[0076] The only difference between this comparative example and Example 1 is that, in the raw material of the surface rubber for the heat-resistant tire tread, the styrene-butadiene rubber is not grafted with acrylate, and the zinc oxide is not composite-modified. Specifically:

[0077] A surface rubber for heat-resistant tire treads is prepared from the following raw materials: 100 parts of natural rubber, 50 parts of styrene-butadiene rubber, 40 parts of carbon black, 10 parts of zinc oxide, 5 parts of stearic acid, 3 parts of an antioxidant, 4 parts of sulfur, and 2 parts of an accelerator, wherein the antioxidant is antioxidant RD and the accelerator is benzothiazole disulfide.

[0078] Proven effectiveness

[0079] The heat-resistant tire treads prepared in Examples 1-3 and Comparative Examples 1-3 were used to make samples using the surface rubbers. The samples were tested for their high-temperature resistance. The specific test results are shown in Table 1:

[0080] High-temperature resistance test: Samples were prepared in accordance with standard GB / T 528-2009 and subjected to high-temperature treatment at 100°C for 7 × 24 hours. The tensile strength of the samples was measured before and after the treatment, and the tensile strength retention was calculated: tensile strength retention = (tensile strength after treatment / tensile strength before treatment) × 100%.

[0081] Table 1

[0082] Tensile strength retention / % Example 1 89.3 Example 2 88.9 Example 3 90.1 Comparative Example 1 82.4 Comparative Example 2 81.7 Comparative Example 3 78.8

[0083] Result Analysis

[0084] By analyzing Examples 1-3 and Comparative Examples 1-3 and combining the data in Table 1, it can be seen that the heat-resistant tire tread rubber prepared by the present invention can maintain a high tensile strength after being treated at a high temperature of 100°C, and the tensile strength retention rate is above 88.9%, indicating that the heat-resistant tire tread rubber provided by the present invention has high high temperature resistance. At the same time, the combined use of acrylate-grafted styrene-butadiene rubber and composite modified zinc oxide can produce synergistic effects and greatly improve the high temperature resistance of the material.

[0085] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0086] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A heat-resistant tire tread rubber, characterized in that: The raw material components are as follows: 100 parts of natural rubber, 45-55 parts of acrylate-grafted styrene-butadiene rubber, 35-45 parts of carbon black, 8-12 parts of composite modified zinc oxide, 4-6 parts of stearic acid, 2-4 parts of antioxidant, 3-5 parts of sulfur and 1-3 parts of accelerator. The composite modified zinc oxide is prepared by composite modification of zinc oxide with ammonium cerium nitrate and rice husk ash.

2. The heat-resistant tire tread rubber according to claim 1, characterized in that: The preparation of acrylate grafted styrene butadiene rubber includes the following: A1. The styrene-butadiene rubber latex is diluted with a diluent and emulsified with an emulsifier to obtain a styrene-butadiene rubber emulsion; A2. Add an acrylate monomer and an initiator to the styrene-butadiene rubber emulsion in step A1 to carry out a grafting reaction to obtain an acrylate-grafted styrene-butadiene rubber.

3. The heat-resistant tire tread rubber according to claim 1, characterized in that: The preparation of acrylate grafted styrene butadiene rubber includes the following: A1. The styrene-butadiene rubber latex was diluted with water, sodium lauryl sulfate was added, and stirred under nitrogen to obtain a styrene-butadiene rubber emulsion; A2. Add acrylate monomer and dibenzoyl peroxide to the styrene-butadiene rubber emulsion in step A1, and carry out grafting reaction at 40-60 ° C for 6-10h. After the reaction, demulsification, centrifugation and drying are carried out in sequence to obtain acrylate-grafted styrene-butadiene rubber.

4. The heat-resistant tire tread rubber according to claim 3, characterized in that: In step A1, the mass ratio of water to styrene-butadiene rubber latex is 8-12:1, and the amount of sodium lauryl sulfate added is 3-10% of the mass of the styrene-butadiene rubber latex.

5. The heat-resistant tire tread rubber according to claim 3, characterized in that: In step A2, the acrylic acid ester monomer is one or a mixture of two or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate and butyl methacrylate.

6. The heat-resistant tire tread rubber according to claim 3, characterized in that: In step A2, the mass ratio of the styrene-butadiene rubber emulsion to the acrylic ester monomer is 10:4-6, and the amount of dibenzoyl peroxide added is 0.5-2% of the mass of the acrylic ester monomer.

7. The heat-resistant tire tread rubber according to claim 1, characterized in that: The preparation of the composite modified zinc oxide includes the following contents: B1. Calcine the rice husk ash at 500-600 ° C for 2-4h and cool to room temperature to obtain activated rice husk ash powder for later use; B2 30 parts of dry zinc oxide and 3-8 parts of cerium ammonium nitrate were mixed, added to 250-350 parts of N, N- dimethylformamide, added base to adjust the pH to 9-10, heated to 60-70 ℃, stirred for 0.5-1.5h to obtain a pretreatment solution; B3. The solution was cooled to 35-45 ° C, 12-18 parts of activated rice husk ash powder was added to the pretreated solution, stirred for 3-5 hours, filtered, vacuum dried, and sieved through 300-500 mesh to obtain a composite modified zinc oxide.

8. The heat-resistant tire tread rubber according to claim 1, characterized in that: The antioxidant is one of antioxidant RD and antioxidant 4020, or a mixture of two or more thereof.

9. The heat-resistant tire tread rubber according to claim 1, characterized in that: The accelerator is one of benzothiazole disulfide and N-cyclohexyl-2-benzothiazole sulfenamide or a mixture of the two.

10. A method for preparing a heat-resistant tire tread surface rubber, for preparing the heat-resistant tire tread surface rubber according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. The natural rubber and acrylate grafted styrene butadiene rubber were masticated, and then the masticated rubber and 30-40% by mass of carbon black were put into an internal mixer for internal mixing, mixing to 110-120 ℃, discharge glue to obtain carbon black plastic; S2. The carbon black plastic and the remaining carbon black, composite modified zinc oxide, antioxidant and stearic acid were mixed in an internal mixer and mixed to 125-130 ° C, drained to obtain a masterbatch; S3. The mixed masterbatch, sulfur and accelerator are put into an internal mixer for mixing, mixing to 105-110°C, and draining to obtain the heat-resistant tire tread surface rubber.