Low-rolling-resistance tread rubber composition, preparation method thereof and new energy tire

Abstract

The invention provides a low-rolling-resistance tread rubber composition, a preparation method thereof and a new energy tire, and relates to the technical field of rubber composite materials. The low-rolling-resistance tread rubber composition comprises 60-70 parts of natural rubber, 50-60 parts of vinyl polybutadiene rubber, 40-50 parts of carbon black, 10-20 parts of a modified heat-conducting filler, 10-20 parts of a functional auxiliary agent, 2-7 parts of a softening agent, 4-8 parts of an active agent, 1-3 parts of a vulcanizing agent, 1-3 parts of an accelerant and 1-3 parts of an anti-aging agent. The tread rubber of the tire contains the modified heat-conducting filler and the functional additive, and the modified heat-conducting filler and the functional additive are matched with other components, so that the binding force between polymers and the filler and between the polymers can be effectively improved, the rolling resistance and heat generation of the tire are reduced, and the endurance mileage of a new energy automobile can be increased.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber composite materials, and in particular to a low rolling resistance tread rubber composition, a preparation method thereof, and a new energy tire. Background Art

[0002] Green tires with low rolling resistance mainly use composite materials of rubber and white carbon black or carbon black as the main raw materials, and combine rubber and filler through silanization reaction. Although the silanization reaction technology increases the bonding effect between polymer and filler and improves the rolling resistance of the tire to a certain extent, the polymer of the tire is generally a composite rubber, and the interface bonding force between different polymers is weak, resulting in unsatisfactory interfacial co-crosslinking performance of the composite rubber, and the relaxation loss of the composite rubber itself is not improved. When white carbon black is used as a filler, the silanization reaction process has high requirements, processing is difficult, and the product batch uniformity is poor. When carbon black is used as a filler, although its reinforcement effect can be increased through modification, the high-reinforcement carbon black has a small particle size and is difficult to disperse in the polymer, making it difficult to exert its full potential. In addition, the modification of carbon black leads to complex processes and high costs.

[0003] Therefore, finding a technology that can effectively improve the bonding strength between polymers and fillers, and between polymers, and reduce tire rolling resistance and heat generation is of vital importance to improving the cruising range of new energy vehicles and promoting the development of new energy vehicles. Summary of the invention

[0004] In order to solve the above problems, a low rolling resistance tread rubber composition, a preparation method thereof and a new energy tire are provided. The tread rubber of the tire contains a modified thermal conductive filler and a functional additive. The two are combined with other components to effectively improve the bonding force between polymer and filler, and between polymer and polymer, reduce the rolling resistance and heat generation of the tire, and can increase the cruising range of new energy vehicles.

[0005] The first aspect of the present invention provides a low rolling resistance tread rubber composition, which comprises, by weight:

[0006] 60-70 parts of natural rubber, 50-60 parts of vinyl polybutadiene rubber, 40-50 parts of carbon black, 10-20 parts of modified thermal conductive filler, 10-20 parts of functional additives, 2-7 parts of softener, 4-8 parts of activator, 1-3 parts of vulcanizer, 1-3 parts of accelerator and 1-3 parts of antioxidant;

[0007] Wherein, the structure of the functional additive is Formula I:

[0008]

[0009] Wherein, R1 is an aromatic group, R2 is an epoxy group, x and y are both integers, x is selected from 2-10, and y is selected from 2-5.

[0010] For new energy vehicles, cruising range is one of the most important performance indicators, which requires tires to have lower rolling resistance, reduce energy consumption of new energy vehicles, and thus increase cruising range. The present invention provides a low rolling resistance tread rubber composition, which uses natural rubber and vinyl polybutadiene rubber as a base material, and can balance the rolling resistance performance of the rubber material. Because vinyl polybutadiene rubber has unsaturated double bonds, the molecular chains of the above-mentioned base material can cross each other during mixing and vulcanization cross-linking, which can strengthen the interaction between the rubber molecular chain and the filler, reduce the filler network strength, reduce or limit the movement of the free end of the rubber molecular chain, reduce hysteresis loss, and thus reduce rolling resistance.

[0011] On the basis of natural rubber and vinyl polybutadiene rubber, a functional additive is also added to the tread rubber composition. According to the structural formula of the functional additive, the functional additive contains two or more epoxy groups and amino groups, which can react with natural rubber and vinyl polybutadiene rubber to form a cross-linked network structure, thereby improving the dispersibility of the functional additive. At the same time, the epoxy groups contained in the functional additive can give the tire thermal conductivity, and can also cooperate with carbon black and modified thermal conductive fillers to form a thermal conductive channel, reduce the heat generation between the rubber material and the filler and between the filler, improve the bonding force and compatibility between the polymer and the filler, and between the polymer and the polymer, reduce the heat generation of the rubber material, and make the rolling resistance of the tire lower. In addition, the benzene ring contained in the functional additive can give the tire a certain stability.

[0012] Optionally, the functional auxiliary agent is prepared by reacting poly(p-phenylene terephthalamide) or poly(m-phenylene isophthalamide) with a halogenated epoxy monomer; the epoxy group in the halogenated epoxy monomer is an ethylene oxide group.

[0013] Optionally, the preparation method of the functional additive comprises the following steps: dissolving poly(p-phenylene terephthalamide) or poly(m-phenylene isophthalamide) and halogenated epoxy monomer in an ethanol solution at a molar ratio of 1:1, and reacting at 50-70° C. for 2-5 hours to obtain the functional additive, wherein the halogenated epoxy monomer is chloroalkylene oxide.

[0014] Optionally, the mass ratio of the modified thermal conductive filler to the functional additive is 1:(1-1.5). Although the addition of the modified thermal conductive filler and the functional additive can improve the thermal conductivity of the tire, if the modified thermal conductive filler is added in excessive amounts, the interaction between the rubber molecular chain and the filler may be reduced, resulting in an increase in the rolling resistance of the tire.

[0015] Optionally, the modified thermal conductive filler is a polydopamine / carbon nanotube / graphene composite material.

[0016] Optionally, the preparation method of the polydopamine / carbon nanotube / graphene composite material comprises the following steps:

[0017] (1) subjecting multi-walled carbon nanotubes to a hydroxylation treatment to obtain hydroxylated multi-walled carbon nanotubes;

[0018] (2) adding dopamine to graphene oxide, and then adding sodium polystyrene sulfonate, reacting at a temperature of 60-70° C. to obtain a polydopamine / graphene composite aqueous solution;

[0019] (3) adding hydroxylated multi-walled carbon nanotubes to the polydopamine / graphene composite aqueous solution, and then adding polyethylene glycol octylphenyl ether, reacting at 100-120° C., centrifuging, washing, and drying to obtain a polydopamine / carbon nanotube / graphene composite material;

[0020] The mass ratio of graphene oxide, dopamine and sodium polystyrene sulfonate is 1:(10-40):(2-7); the mass of the hydroxylated multi-walled carbon nanotubes is 1-2 times the mass of the graphene oxide;

[0021] The concentration of polyethylene glycol octylphenyl ether in the polydopamine / graphene composite aqueous solution is 0.2wt%-0.4wt%.

[0022] In the present invention, a modified thermal conductive filler is synthesized by a simple self-assembly method, dopamine and graphene oxide are mixed and reacted, and the reaction between the two leads to partial amination of graphene oxide and oligomerization of dopamine, which can improve the compatibility with rubber, improve the coordination and dispersion effect with carbon black, and improve the dispersion of carbon black and the modified thermal conductive filler itself, thereby reducing the heat generation of the rubber and reducing the rolling resistance. In addition, adding hydroxylated multi-walled carbon nanotubes as the second carbon skeleton component can further improve the thermal conductivity of the tire on the one hand; on the other hand, the hydroxylated multi-walled carbon nanotubes can chemically react with the functional groups on the surface of partially aminated graphene oxide, play an isolating role, and reduce agglomeration; at the same time, it can improve the compatibility with functional additives, facilitate its uniform dispersion along the cross-linked network of the functional additives, and cooperate with the functional additives to enhance the thermal conductivity of the tire and reduce the rolling resistance of the tire.

[0023] Optionally, the method for preparing hydroxylated multi-walled carbon nanotubes comprises the following steps:

[0024] The multi-walled carbon nanotubes are reacted with a mixture of potassium hydroxide and sodium hydroxide at 180-200° C., and washed with hydrochloric acid and deionized water in sequence; the mixed solution is then dialyzed with a dialysis bag until the pH value reaches neutral to obtain a neutral dialysate, and the neutral dialysate is then vacuum freeze-dried to obtain hydroxylated multi-walled carbon nanotubes.

[0025] Optionally, the mass ratio of potassium hydroxide to sodium hydroxide is (3-4): 1. Potassium hydroxide and sodium hydroxide provide an alkaline environment for the hydroxylation modification of multi-walled carbon nanotubes, which can improve the compatibility of the modified thermal conductive filler with rubber, while promoting better grafting with graphene oxide, forming a thermal conductive path, and reducing tire rolling resistance.

[0026] Optionally, the surface area of ​​the multi-walled carbon nanotubes is 800-900 m 2 / g, the tube diameter is distributed in the range of 300-500nm, and the length is distributed in the range of 600-2000nm;

[0027] The particle size of the graphene oxide is 100-300 nm. The multi-walled carbon nanotubes with the above diameter and length can be better dispersed evenly. At the same time, the multi-walled carbon nanotubes with this length can better cooperate with the rubber, improve compatibility, and play a reinforcing role; cooperate with the functional additives to improve thermal conductivity. If the length of the multi-walled carbon nanotubes is too long, although it is conducive to dispersion, it will cause the stability of the tire to decrease to a certain extent.

[0028] Optionally, the softener is heavy naphthenic oil;

[0029] and / or the active agents are zinc oxide and stearic acid;

[0030] and / or the vulcanizing agent is at least one of dibenzoyl peroxide, tetramethylthiuram disulfide, barium peroxide, cadmium peroxide, magnesium peroxide, zinc peroxide, bis(2,4-dichloroformyl)peroxide, di-tert-butyl peroxide, 1,4-di-tert-butylperoxyisopropylbenzene, diisopropylbenzene peroxide, tert-butyl perbenzoate, tert-butyl isopropyl peroxide, isochloropropyl peroxide, tert-butyl isopropyl carbonate, and tert-butyl peroxycarbonate;

[0031] and / or the accelerator is N-tert-butyl-2-benzothiazole sulfenamide;

[0032] And / or the antioxidant is selected from at least one of physical protective wax, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (abbreviated as antioxidant 6PPD) and 2,2,4-trimethyl-1,2-dihydroquinoline polymer (abbreviated as antioxidant RD).

[0033] A second aspect of the present invention provides a method for preparing a low rolling resistance tread rubber composition, the preparation method comprising the following steps:

[0034] (1) mixing the natural rubber, vinyl polybutadiene rubber and functional additives in one step, then adding carbon black, modified thermal conductive filler, softener, activator and antioxidant for two-step mixing and then draining to obtain a mixed rubber;

[0035] (2) The rubber mixture, accelerator and vulcanizer are mixed in three steps, and the tread rubber composition is obtained after the rubber mixture is discharged and cooled.

[0036] Optionally, the temperature of the one-step mixing is 50-60° C. and the time is 5-15 min;

[0037] The temperature of the two-step mixing is 100-120°C and the time is 5-10min;

[0038] The temperature of the three-step mixing is 70-80° C. and the time is 2-3 minutes.

[0039] In step (1), the functional additive and the two rubber substrates are firstly mixed in one step to increase the mixing uniformity among the three, which is conducive to the uniform dispersion of the functional additive in the rubber substrate. On the basis of the uniform dispersion of the functional additive, carbon black, modified thermal conductive filler and other ingredients are added for two-step mixing. The groups contained in the functional additive can improve the dispersion uniformity of carbon black and modified thermal conductive filler, so that the molecular chains of carbon black, modified thermal conductive filler and functional additive form a dense thermal conductive path, thereby improving the thermal conductivity of the tire.

[0040] A third aspect of the present invention provides a new energy tire, comprising a tread, a buffer layer, a cord layer and a bead, wherein the tread adopts the low rolling resistance tread rubber composition.

[0041] Compared with the prior art, the present invention achieves at least one of the following beneficial effects:

[0042] (1) The present invention provides a low rolling resistance tread rubber composition, wherein the tread rubber of the tire contains a modified thermal conductive filler and a functional additive, which, when combined with other components, can effectively improve the bonding strength between polymer and filler, and between polymer and polymer, reduce the rolling resistance and heat generation of the tire, and can improve the cruising range of new energy vehicles.

[0043] (2) The tread rubber composition of the present invention also contains a functional additive, which can react with natural rubber and vinyl polybutadiene rubber to form a cross-linked network structure, thereby improving the dispersibility of the functional additive. At the same time, the epoxy group contained in the functional additive can give the tire thermal conductivity, and can also cooperate with carbon black and modified thermal conductive fillers to form a thermal conductive channel, thereby reducing the heat generated between the rubber and the filler and between the filler and the filler, and improving the bonding force and compatibility between the polymer and the filler, as well as between the polymer and the polymer, thereby reducing the heat generated by the rubber and reducing the hysteresis heat generated by the tire, thereby making the rolling resistance of the tire lower.

[0044] (3) The present invention modifies graphene oxide and multi-walled carbon nanotubes by self-assembly. The hydroxylated multi-walled carbon nanotubes can react chemically with the functional groups on the surface of partially amino-modified graphene oxide to isolate and reduce aggregation. At the same time, the compatibility with functional additives can be improved, making it easier for them to be evenly dispersed along the cross-linked network of the functional additives, and synergistically enhance the thermal conductivity of the tire and reduce the rolling resistance of the tire with the functional additives. DETAILED DESCRIPTION

[0045] In order to more clearly illustrate the overall concept of the present invention, a detailed description is given below by way of examples.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0047] Example 1

[0048] A low rolling resistance tread rubber composition and a preparation method thereof and a new energy tire, the tire comprising a tread, a buffer layer, a cord layer and a bead. The tread is made by mixing and vulcanizing the low rolling resistance tread rubber composition, which comprises: 60 parts of natural rubber, 55 parts of vinyl polybutadiene rubber, 40 parts of carbon black, 10 parts of modified thermal conductive filler, 10 parts of functional additives, 2 parts of softener heavy naphthenic oil, 5 parts of active agent zinc oxide, 2 parts of vulcanizing agent dibenzoyl peroxide, 1 part of accelerator N-tert-butyl-2-benzothiazole sulfenamide and 1 part of antioxidant 6PPD.

[0049] The functional additive has a structural formula of Formula I, and the preparation method of the functional additive is as follows: poly(p-phenylene terephthalamide) and chloromethyl ethylene oxide monomer are dissolved in an ethanol solution at a molar ratio of 1:1, and reacted at 50° C. for 2 hours to obtain the functional additive. Wherein x and y are both 3.

[0050] The preparation method of the modified thermal conductive filler polydopamine / carbon nanotube / graphene composite material comprises the following steps:

[0051] (1) The specific surface area is 800m 2 / g, multi-walled carbon nanotubes with a tube diameter of 300nm and a length of 600nm are reacted with a mixture of potassium hydroxide and sodium hydroxide, the mass ratio of potassium hydroxide to sodium hydroxide being 3:1, and the reaction is carried out at 180°C, and the mixture is washed with hydrochloric acid and deionized water in sequence; the mixed solution is then dialyzed with a dialysis bag until the pH value reaches 7 to obtain a neutral dialysate, and the neutral dialysate is then freeze-dried in vacuum to obtain hydroxylated multi-walled carbon nanotubes.

[0052] (2) dopamine is added to graphene oxide with a particle size of 200 nm, and then sodium polystyrene sulfonate is added, and the mixture is reacted at a temperature of 60° C. to obtain a polydopamine / graphene composite aqueous solution, wherein the mass ratio of graphene oxide, dopamine, and sodium polystyrene sulfonate is 1:10:2.

[0053] (3) Adding hydroxylated multi-walled carbon nanotubes of the same mass as that of graphene oxide to the polydopamine / graphene composite aqueous solution, and then adding polyethylene glycol octylphenyl ether so that the concentration of polyethylene glycol octylphenyl ether in the polydopamine / graphene composite aqueous solution is 0.2wt%, reacting at 100°C, centrifuging, washing, and drying to obtain a polydopamine / carbon nanotube / graphene composite material.

[0054] The manufacturing process of the above tire comprises the following steps:

[0055] (1) Natural rubber, vinyl polybutadiene rubber and functional additives are mixed in one step at 50°C for 5 minutes, and then carbon black, modified thermal conductive filler, softener, activator and antioxidant are added and mixed in two steps at 100°C for 5 minutes, and then the rubber is discharged to obtain a mixed rubber.

[0056] (2) The mixed rubber, accelerator and vulcanizer are mixed in three steps at 70° C. for 2 minutes, and the tread rubber composition is obtained after the rubber is discharged and cooled.

[0057] (3) The cord layer, the breaker layer and the tire bead are assembled and formed, and the low rolling resistance tread rubber composition is attached to the breaker layer to form a tread, and then the tread is vulcanized to obtain a tire.

[0058] Example 2

[0059] A low rolling resistance tread rubber composition and a preparation method thereof and a new energy tire, the tire comprising a tread, a buffer layer, a cord layer and a bead. The tread is made by mixing and vulcanizing the low rolling resistance tread rubber composition, the low rolling resistance tread rubber composition comprising: 70 parts of natural rubber, 60 parts of vinyl polybutadiene rubber, 50 parts of carbon black, 10 parts of modified thermal conductive filler, 20 parts of functional additives, 2 parts of softener heavy naphthenic oil, 5 parts of active agent stearic acid, 2 parts of vulcanizing agent tetramethylthiuram disulfide, 1 part of accelerator N-tert-butyl-2-benzothiazole sulfenamide and 1 part of antioxidant RD.

[0060] The functional additive has a structural formula of Formula I, and the preparation method of the functional additive is as follows: poly(m-phenylene isophthalamide) and chloromethyl ethylene oxide monomer are dissolved in an ethanol solution at a molar ratio of 1:1, and reacted at 70° C. for 4 hours to obtain the functional additive. Wherein x and y are both 4.

[0061] The preparation method of the modified thermal conductive filler polydopamine / carbon nanotube / graphene composite material comprises the following steps:

[0062] (1) The specific surface area is 900m 2 / g, multi-walled carbon nanotubes with a tube diameter of 500nm and a length of 2000nm are reacted with a mixture of potassium hydroxide and sodium hydroxide, the mass ratio of potassium hydroxide to sodium hydroxide being 4:1, and the reaction is carried out at 200°C, and the mixture is washed with hydrochloric acid and deionized water in sequence; the mixed solution is then dialyzed with a dialysis bag until the pH value reaches 7 to obtain a neutral dialysate, and the neutral dialysate is then freeze-dried in vacuum to obtain hydroxylated multi-walled carbon nanotubes.

[0063] (2) dopamine is added to graphene oxide with a particle size of 100 nm, and then sodium polystyrene sulfonate is added, and the mixture is reacted at a temperature of 70° C. to obtain a polydopamine / graphene composite aqueous solution, wherein the mass ratio of graphene oxide, dopamine, and sodium polystyrene sulfonate is 1:40:2.

[0064] (3) Adding hydroxylated multi-walled carbon nanotubes of the same mass as that of graphene oxide to the polydopamine / graphene composite aqueous solution, and then adding polyethylene glycol octylphenyl ether so that the concentration of polyethylene glycol octylphenyl ether in the polydopamine / graphene composite aqueous solution is 0.4wt%, reacting at 120°C, centrifuging, washing, and drying to obtain a polydopamine / carbon nanotube / graphene composite material.

[0065] The manufacturing process of the above tire comprises the following steps:

[0066] (1) Natural rubber, vinyl polybutadiene rubber and functional additives are mixed in one step at 60°C for 10 minutes, and then carbon black, modified thermal conductive filler, softener, activator and antioxidant are added and mixed in two steps at 120°C for 5 minutes, and then the rubber is discharged to obtain a mixed rubber.

[0067] (2) The mixed rubber, accelerator and vulcanizer are mixed in three steps at 80° C. for 2 minutes, and the tread rubber composition is obtained after the rubber is discharged and cooled.

[0068] (3) The cord layer, the breaker layer and the tire bead are assembled and formed, and the low rolling resistance tread rubber composition is attached to the breaker layer to form a tread, and then the tread is vulcanized to obtain a tire.

[0069] Example 3

[0070] A low rolling resistance tread rubber composition and a preparation method thereof and a new energy tire, the tire comprising a tread, a buffer layer, a cord layer and a bead. The tread is made by mixing and vulcanizing the low rolling resistance tread rubber composition, which comprises: 65 parts of natural rubber, 55 parts of vinyl polybutadiene rubber, 50 parts of carbon black, 15 parts of modified thermal conductive filler, 15 parts of functional additives, 4 parts of softener heavy naphthenic oil, 5 parts of active agent stearic acid, 2 parts of vulcanizing agent tert-butyl perbenzoate, 2 parts of accelerator N-tert-butyl-2-benzothiazole sulfenamide and 2 parts of antioxidant RD.

[0071] The functional additive has a structural formula of Formula I, and the preparation method of the functional additive is as follows: poly(p-phenylene terephthalamide) and chloromethyl ethylene oxide monomer are dissolved in an ethanol solution at a molar ratio of 1:1, and reacted at 60° C. for 4 hours to obtain the functional additive. Wherein x and y are both 5.

[0072] The preparation method of the modified thermal conductive filler polydopamine / carbon nanotube / graphene composite material comprises the following steps:

[0073] (1) The specific surface area is 850m 2 / g, multi-walled carbon nanotubes with a tube diameter of 400nm and a length of 1000nm are reacted with a mixture of potassium hydroxide and sodium hydroxide, the mass ratio of potassium hydroxide to sodium hydroxide being 3:1, and the reaction is carried out at 200°C, and the mixture is washed with hydrochloric acid and deionized water in sequence; the mixed solution is then dialyzed with a dialysis bag until the pH value reaches 7 to obtain a neutral dialysate, and the neutral dialysate is then freeze-dried in vacuum to obtain hydroxylated multi-walled carbon nanotubes.

[0074] (2) dopamine is added to graphene oxide with a particle size of 200 nm, and then sodium polystyrene sulfonate is added, and the mixture is reacted at a temperature of 65° C. to obtain a polydopamine / graphene composite aqueous solution, wherein the mass ratio of graphene oxide, dopamine, and sodium polystyrene sulfonate is 1:20:4.

[0075] (3) Adding hydroxylated multi-walled carbon nanotubes of the same mass as that of graphene oxide to the polydopamine / graphene composite aqueous solution, and then adding polyethylene glycol octylphenyl ether so that the concentration of polyethylene glycol octylphenyl ether in the polydopamine / graphene composite aqueous solution is 0.3wt%, reacting at 110°C, centrifuging, washing, and drying to obtain a polydopamine / carbon nanotube / graphene composite material.

[0076] The manufacturing process of the above tire comprises the following steps:

[0077] (1) Natural rubber, vinyl polybutadiene rubber and functional additives are mixed in one step at 60°C for 10 minutes, and then carbon black, modified thermal conductive filler, softener, activator and antioxidant are added and mixed in two steps at 120°C for 5 minutes, and then the rubber is discharged to obtain a mixed rubber.

[0078] (2) The mixed rubber, accelerator and vulcanizer are mixed in three steps at 80° C. for 2 minutes, and the tread rubber composition is obtained after the rubber is discharged and cooled.

[0079] (3) The cord layer, the breaker layer and the tire bead are assembled and formed, and the low rolling resistance tread rubber composition is attached to the breaker layer to form a tread, and then the tread is vulcanized to obtain a tire.

[0080] Example 4

[0081] Based on Example 3, the main difference is that the modified thermal conductive filler is a polydopamine / graphene composite material, and the preparation method of the polydopamine / graphene composite material comprises the following steps:

[0082] Add dopamine to graphene oxide, then add sodium polystyrene sulfonate, react at a temperature of 65° C. to obtain a polydopamine / graphene composite aqueous solution;

[0083] The polydopamine / graphene composite aqueous solution is centrifuged, washed and dried to obtain a polydopamine / graphene composite material.

[0084] The other steps are the same as those in Example 3.

[0085] Example 5

[0086] Based on Example 3, the main difference is that the modified thermal conductive filler is only hydroxylated multi-walled carbon nanotubes. The other steps are the same as Example 3.

[0087] Example 6

[0088] Based on Example 3, the main difference is that the mass of hydroxylated multi-walled carbon nanotubes is 5 times the mass of graphene oxide. Other steps are the same as Example 3.

[0089] Example 7

[0090] Based on Example 3, the main difference is that the length of the multi-walled carbon nanotubes is 1 micron, and the other steps are the same as Example 3.

[0091] Comparative Example 1

[0092] Based on Example 1, the main difference is that no functional additive is added, and the other steps are the same as Example 1.

[0093] Comparative Example 2

[0094] Based on Example 1, the main difference is that the modified thermal conductive filler is only graphene oxide, and the other steps are the same as Example 1.

[0095] Comparative Example 3

[0096] Based on Example 1, the main difference is that 30 parts of functional additives are used, and the other steps are the same as Example 1.

[0097] Comparative Example 4

[0098] Based on Example 1, the main difference is that 100 parts of natural rubber are used, and the other steps are the same as Example 1.

[0099] The tread rubber compositions obtained in the examples and comparative examples were vulcanized separately to obtain tread samples, and the mechanical properties, rolling resistance properties and heat generation properties of the tread samples were tested. The specific test results are shown in Table 1.

[0100] The rolling resistance performance is tested using a DMA instrument in accordance with GB / T9870.1-2006, and the rolling resistance performance is generally characterized by a 60°C loss factor.

[0101] Heat generation: GB / T1687-1993 standard was used to test the compression heat generation of the tread samples prepared in the embodiment and the comparative example.

[0102] The tensile strength and tear strength were tested according to GB / T528-2009.

[0103] Table 1

[0104] Dissipation factor 60℃ Heat generation temperature / ℃ Tensile strength / MPa Tear strength / N / mm Example 1 0.087 15 31 46 Example 2 0.088 16 30 45 Example 3 0.085 14 32 47 Example 4 0.095 16 29 44 Example 5 0.092 17 27 42 Example 6 0.090 16 25 40 Example 7 0.094 19 24 38 Comparative Example 1 0.207 35 17 22 Comparative Example 2 0.131 23 21 35 Comparative Example 3 0.114 21 28 40 Comparative Example 4 0.122 22 26 37

[0105] Referring to Table 1, it can be seen that the tread rubber composition prepared by the present application has a loss factor of no more than 0.1 at 60°C, which proves that the tire prepared by the tread rubber composition of the present application has low rolling resistance performance; the heat generation temperature is no more than 20°C, indicating that the tire prepared by the tread rubber composition of the present application has good thermal conductivity; in addition, the tread rubber composition of the present application has a tensile strength of no less than 23 MPa, a tear strength of no less than 35 N / mm, and has good mechanical properties.

[0106] In summary, the tire prepared in the present application can meet the endurance requirements of new energy vehicles and has low rolling resistance and high thermal conductivity.

[0107] The above description is only an 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 substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A low rolling resistance tread rubber composition, characterized in that: The low rolling resistance tread rubber composition comprises, by weight: 60-70 parts of natural rubber, 50-60 parts of vinyl polybutadiene rubber, 40-50 parts of carbon black, 10-20 parts of modified thermal conductive filler, 10-20 parts of functional additives, 2-7 parts of softener, 4-8 parts of activator, 1-3 parts of vulcanizer, 1-3 parts of accelerator and 1-3 parts of antioxidant; Wherein, the structure of the functional additive is Formula I: Wherein, R1 is an aromatic group, R2 is an epoxy group, x and y are both integers, x is selected from 2-10, and y is selected from 2-5.

2. The low rolling resistance tread rubber composition according to claim 1, characterized in that: The functional auxiliary agent is prepared by reacting poly(p-phenylene terephthalamide) or poly(m-phenylene isophthalamide) with a halogenated epoxy monomer; the epoxy group in the halogenated epoxy monomer is an ethylene oxide group.

3. The low rolling resistance tread rubber composition according to claim 1, characterized in that: The mass ratio of the modified thermal conductive filler to the functional additive is 1:(1-1.5).

4. The low rolling resistance tread rubber composition according to claim 1, characterized in that: The modified thermal conductive filler is a polydopamine / carbon nanotube / graphene composite material.

5. The low rolling resistance tread rubber composition according to claim 4, characterized in that: The preparation method of the polydopamine / carbon nanotube / graphene composite material comprises the following steps: (1) subjecting multi-walled carbon nanotubes to a hydroxylation treatment to obtain hydroxylated multi-walled carbon nanotubes; (2) adding dopamine to graphene oxide, and then adding sodium polystyrene sulfonate, reacting at a temperature of 60-70° C. to obtain a polydopamine / graphene composite aqueous solution; (3) adding hydroxylated multi-walled carbon nanotubes to the polydopamine / graphene composite aqueous solution, and then adding polyethylene glycol octylphenyl ether, reacting at 100-120° C., centrifuging, washing, and drying to obtain a polydopamine / carbon nanotube / graphene composite material; The mass ratio of graphene oxide, dopamine and sodium polystyrene sulfonate is 1:(10-40):(2-7); the mass of the hydroxylated multi-walled carbon nanotubes is 1-2 times the mass of the graphene oxide; The concentration of polyethylene glycol octylphenyl ether in the polydopamine / graphene composite aqueous solution is 0.2wt%-0.4wt%.

6. The low rolling resistance tread rubber composition according to claim 5, characterized in that: The method for preparing hydroxylated multi-walled carbon nanotubes comprises the following steps: The multi-walled carbon nanotubes are reacted with a mixture of potassium hydroxide and sodium hydroxide at 180-200° C., and washed with hydrochloric acid and deionized water in sequence; the mixed solution is then dialyzed with a dialysis bag until the pH value reaches neutral to obtain a neutral dialysate, and the neutral dialysate is then vacuum freeze-dried to obtain hydroxylated multi-walled carbon nanotubes.

7. The low rolling resistance tread rubber composition according to claim 5, characterized in that: The specific surface area of ​​multi-walled carbon nanotubes is 800-900m 2 / g, the tube diameter is distributed in the range of 300-500nm, and the length is distributed in the range of 600-2000nm; And / or the particle size of graphene oxide is 100-300nm.

8. The low rolling resistance tread rubber composition according to claim 1, characterized in that: The softener is heavy naphthenic oil; and / or the active agent is zinc oxide or stearic acid; and / or the vulcanizing agent is at least one of dibenzoyl peroxide, tetramethylthiuram disulfide, barium peroxide, cadmium peroxide, magnesium peroxide, zinc peroxide, bis(2,4-dichloroformyl)peroxide, di-tert-butyl peroxide, 1,4-di-tert-butylperoxyisopropylbenzene, diisopropylbenzene peroxide, tert-butyl perbenzoate, tert-butyl isopropyl peroxide, isochloropropyl peroxide, tert-butyl isopropyl carbonate, and tert-butyl peroxycarbonate; and / or the accelerator is N-tert-butyl-2-benzothiazole sulfenamide; And / or the antioxidant is selected from at least one of physical protective wax, antioxidant 6PPD and antioxidant RD.

9. A method for preparing the low rolling resistance tread rubber composition according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: (1) mixing natural rubber, vinyl polybutadiene rubber and functional additives in one step, then adding carbon black, modified thermal conductive filler, softener, activator and antioxidant for two-step mixing and then discharging to obtain a mixed rubber; (2) The rubber compound, the accelerator and the vulcanizing agent are mixed in three steps, and the tread rubber composition is obtained after the rubber compound is discharged and cooled.

10. A new energy tire, characterized in that: The invention comprises a tread, a buffer layer, a cord layer and a bead, wherein the tread adopts the low rolling resistance tread rubber composition according to any one of claims 1 to 8.

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