High-temperature-resistant new energy automobile tire tread rubber composition

Abstract

The invention relates to the technical field of tire rubber manufacturing, and discloses a high-temperature-resistant new energy automobile tire tread rubber composition. The rubber composition is prepared by mixing the following raw materials based on 100 parts by weight of raw rubber: 40-60 parts of natural rubber, 40-60 parts of synthetic rubber, 5-45 parts of filler, 10-15 parts of unsaturated polyester resin, 15-25 parts of liquid butadiene rubber, 0.5-2 parts of a cross-linking agent and 5-15 parts of a plasticizer. The molecular structure of the unsaturated polyester resin contains carboxyl groups, the molecular weight is 5000-8000, and the unsaturation degree range is 0.2-0.8; the liquid butadiene rubber is modified liquid butadiene rubber with terminal amino and can react with unsaturated polyester resin to perform cross-linking reaction, so that the wear resistance, the thermal stability and the overall performance of the tire are effectively improved, and the method is suitable for manufacturing tires of new energy cars.

Description

Technical Field

[0001] The present invention relates to the technical field of tire rubber manufacturing, and more specifically, to a high-temperature resistant tread rubber composition for new energy vehicle tires. Background Art

[0002] With the rapid development of new energy sedans, the improvement of tire performance has become one of the key factors in enhancing vehicle energy efficiency, driving safety, and comfort. New energy sedans have high energy utilization efficiency, so the performance requirements for tires are more stringent, especially in terms of wear resistance, energy efficiency, and environmental friendliness in high-temperature environments. Traditional tire tread formulations mostly use natural rubber and synthetic rubber. However, with the changing demands, new tire formulations need to address the following issues: 1) improving the wear resistance of tires under high-temperature and high-speed driving; 2) enhancing the high-temperature stability of tires to prevent excessive wear caused by thermal expansion; 3) ensuring the environmental friendliness and low-emission characteristics of tire materials to meet the green requirements of new energy vehicles. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a high-temperature resistant tread rubber composition for new energy vehicle tires, which improves the wear resistance, high-temperature stability, and overall performance of the tire tread rubber composition and is applicable to the manufacture of tires for new energy sedans.

[0004] To achieve the above object, the present invention adopts the following technical solutions: A high-temperature resistant tread rubber composition for new energy vehicle tires, wherein the rubber composition is prepared by mixing raw materials of the following components based on 100 parts by weight of raw rubber: 40 - 60 parts of natural rubber, 40 - 60 parts of synthetic rubber, 5 - 45 parts of filler, 10 - 15 parts of unsaturated polyester resin, 15 - 25 parts of liquid cis-1,4-polybutadiene rubber, 0.5 - 2 parts of crosslinking agent, 5 - 15 parts of plasticizer; The unsaturated polyester resin has a carboxyl group in its molecular structure, a molecular weight of 5000 - 10000, and an unsaturation range of 0.2 - 0.8; The liquid cis-1,4-polybutadiene rubber is a modified liquid cis-1,4-polybutadiene rubber with terminal amino groups and can react with the unsaturated polyester resin.

[0005] Among them, liquid cis-1,4-polybutadiene rubber is a synthetic rubber polymerized from butadiene. It contains a large number of double bond structures in its molecular chain, which can crosslink with other rubber molecules and additives to form a more stable network structure, enhance the anti-wear ability of the tire tread, and extend the service life of the tire.

[0006] Compared with traditional solid rubber, liquid cis-1,4-polybutadiene rubber has a lower molecular weight and better fluidity, can be more evenly dispersed in the rubber compound, and effectively improves the processing performance of the rubber compound. Liquid cis-1,4-polybutadiene rubber can reduce the Mooney viscosity of the rubber compound, reduce the energy consumption during the mixing process, and improve the mixing efficiency. At the same time, it can also enhance the fluidity of the rubber compound, making it easier to fill the mold during the molding process, and ensuring that the complex patterns on the tire tread can be accurately formed.

[0007] Preferably, the viscosity of the liquid cis-1,4-polybutadiene rubber is 50 - 150 mPa•s.

[0008] Preferably, the degree of unsaturation of the unsaturated polyester resin molecule ranges from 0.4 to 0.6.

[0009] As the reinforcing agent in the rubber composition constituting the present invention, there are various types and no particular limitation. Commonly used reinforcing agents can include carbon black, silica, and other such as organic reinforcing agents, nano-reinforcing materials, etc. These reinforcing agents can be used alone or in combination of 2 or more.

[0010] As the carbon black, furnace black, thermal black, acetylene black, Ketjen black, etc. can be mentioned. Among these, from the viewpoint of further improving the mechanical strength of the rubber composition, furnace black is preferred. They can be used alone in 1 type or in combination of 2 or more types. In addition, in order to further improve the affinity with the rubber component, the surface can be subjected to an organic treatment.

[0011] As the silica, it means a silica silicate-based filler material, and not only represents silica in the narrow sense, and can be appropriately selected and used from existing materials used as reinforcing filler materials. For example, wet silica (hydrous silicic acid), dry silica (anhydrous silica), etc. can be mentioned. Among these, from the viewpoint of further improving the processability, wet skid resistance, and abrasion resistance, wet silica is preferred. They can be used alone in 1 type or in combination of 2 or more types. In addition, in order to further improve the affinity with the rubber component, it is preferred to form a treatment layer formed by a surface treatment agent on the surface.

[0012] As organic reinforcing agents, lignin, starch, cellulose, organic fibers, etc. can be cited. For example, lignin, which is rich in sources, can partially replace carbon black, reduce the production cost of tires, and also improve the processing performance and anti-aging performance of rubber compounds. Magnesium lignosulfonate, acetylated lignin, epoxidized lignin, etc. can be cited. For example, starch has the advantages of being renewable and low in price. When applied in tires, it can improve the tensile strength and tear strength of rubber compounds. However, due to its strong hydrophilicity, appropriate treatment is required during use to improve its compatibility with rubber. Starch acetate, starch phosphate, hydroxypropyl starch, etc. can be cited. For example, for organic fibers, aramid fibers, polyester fibers, aramid pulp, etc. can be cited; for example, aramid fibers have the characteristics of high strength and high modulus and can significantly improve the strength and tear resistance of tires; polyester fibers have relatively low costs and can improve the dimensional stability and heat resistance of rubber compounds in tire rubber, enhancing the comprehensive performance of tires.

[0013] As nano-reinforcing materials, nano-clay, carbon nanotubes, etc. can be cited. For example, nano-clay has a unique lamellar structure and can significantly improve the barrier performance and mechanical properties of rubber compounds. For example, carbon nanotubes have excellent mechanical properties and electrical conductivity and can improve the strength, wear resistance, and electrical conductivity of tires.

[0014] Preferably, the filler is carbon black and / or silica, with 10 - 30 parts of carbon black and 5 - 15 parts of silica.

[0015] Preferably, the filler is carbon black and silica, with 20 - 30 parts of carbon black and 5 - 10 parts of silica.

[0016] As crosslinking agents, sulfur and sulfur donors, organic peroxides, resin-based crosslinking agents, phenolic resin crosslinking agents, metal oxide crosslinking agents, amine crosslinking agents, etc. can be cited. More specifically, benzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, tert-butyl cumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5 - dimethyl - 2,5 - bis(tert-butylperoxy)hexane, 2,5 - dimethyl - 2,5 - bis(benzoylperoxy)hexane, 2,5 - dimethyl - 2,5 - bis(tert-butylperoxy)hex-3-yne, 1,3 - bis(tert-butylperoxyisopropyl)benzene, di-tert-butyl peroxide diisopropylbenzene, tert-butyl peroxide benzene, 2,4 - dichlorobenzoyl peroxide, 1,1 - di-tert-butylperoxy - 3,3,5 - trimethylsiloxane, n-butyl 4,4 - di-tert-butylperoxypentanoate, morpholine disulfide, sulfur, insoluble sulfur, etc. can be cited. These crosslinking agents can be used alone or in combination of two or more.

[0017] Preferably, the crosslinking agent is sulfur and / or peroxide.

[0018] As a plasticizer, it plays an important role in improving the processing performance and adjusting the physical properties of the rubber composition. These plasticizer molecules have a relatively small molecular weight and good solubility, and can be inserted between the rubber molecular chains, weakening the intermolecular forces between the rubber molecular chains or increasing the mobility of the rubber molecular chains. Examples include phthalates, fatty acid esters, polyesters, epoxidized compounds, petroleum-based plasticizers, quaternary ammonium salts, etc. More specifically, examples include DMP (dimethyl phthalate), DEP (diethyl phthalate), DBP (dibutyl phthalate), DOP (dioctyl phthalate), DINP (diisononyl phthalate), DIDP (diisodecyl phthalate), BBP (butyl benzyl phthalate), DOA (dioctyl adipate), DOS (dioctyl sebacate), epoxidized soybean oil, epoxidized fatty acid methyl ester, paraffinic processing oil, naphthenic processing oil, aromatic processing oil, liquid paraffin, etc. These plasticizers can be used alone or in combination of two or more.

[0019] Preferably, the plasticizer is a phthalate, a quaternary ammonium salt or a fatty acid ester.

[0020] In the rubber composition of the present invention, in addition to the above-mentioned components, compounding agents commonly used in the rubber field such as silane coupling agents, vulcanization accelerators, antioxidants, softeners, anti-scorching agents, anti-ozone agents, blowing agents, vulcanization retarders, etc. can be appropriately compounded. Preferably, 1-5 parts of zinc oxide, 1-3 parts of stearic acid, 1-5 parts of antioxidant, 0.5-2.5 parts of accelerator.

[0021] The type of the silane coupling agent is not particularly limited, and commonly used silane coupling agents can be used. Examples include sulfide-based, polysulfide-based, thioester-based, thiol-based, olefin-based, epoxy-based, amino-based, alkyl-based silane coupling agents, etc. They can be used alone or in combination of two or more. Among these, sulfide-based silane coupling agents and amino-based silane coupling agents are preferred.

[0022] Examples of the silane coupling agent of the sulfide type include bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(3-methyldimethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-triethoxysilylpropyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(3-methyldimethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-trimethoxysilylpropyl)trisulfide, bis(3-methyldimethoxysilylpropyl)trisulfide, bis(2-triethoxysilylethyl)trisulfide, bis(3-monoethoxydimethylsilylpropyl)tetrasulfide, bis(3-monoethoxydimethylsilylpropyl)trisulfide, bis(3-monoethoxydimethylsilylpropyl)disulfide, bis(3-monomethoxydimethylsilylpropyl)tetrasulfide, bis(3-monomethoxydimethylsilylpropyl)trisulfide, bis(3-monomethoxydimethylsilylpropyl)disulfide, bis(2-monoethoxydimethylsilylethyl)tetrasulfide, bis(2-monoethoxydimethylsilylethyl)trisulfide, bis(2-monoethoxydimethylsilylethyl)disulfide, etc. Among these, bis(3-triethoxysilylpropyl)tetrasulfide is preferred.

[0023] Examples of the silane coupling agent of the thioester type include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, 3-lauroylthiopropyltriethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane, 3-hexanoylthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octanoylthioethyltrimethoxysilane, 2-decanoylthioethyltrimethoxysilane, 2-lauroylthioethyltrimethoxysilane, etc.

[0024] Examples of the silane coupling agent of the mercaptan type include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, etc.

[0025] Examples of the silane coupling agent of the olefin series include dimethoxymethylvinylsilane, vinyltrimethoxysilane, dimethylethoxyvinylsilane, diethoxymethylvinylsilane, triethoxyvinylsilane, vinyltris(2-methoxyethoxy)silane, allyltrimethoxysilane, allyltriethoxysilane, p-styryltrimethoxysilane, 3-(methoxydimethoxydimethylsilyl)propyl acrylate, 3-(trimethoxysilyl)propyl acrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-(triethoxysilyl)propyl methacrylate, 3-[tris(trimethylsiloxy)silyl]propyl methacrylate, etc.

[0026] Examples of the silane coupling agent of the epoxy series include 3-glycidoxypropyl(dimethoxy)methylsilane, 3-glycidoxypropyltrimethoxysilane, diethoxy(3-glycidoxypropyl)methylsilane, triethoxy(3-glycidoxypropyl)silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc.

[0027] Examples of the silane coupling agent of the amino series include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-ethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, etc. Among these, 3-aminopropyltriethoxysilane is preferred.

[0028] Examples of the silane coupling agent of the alkyl series include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, etc.

[0029] The type of the vulcanization accelerator is not particularly limited, and the commonly used vulcanization accelerators can be used. Examples include sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamate-based, aldehyde-amine-based or aldehyde-ammonia-based, etc. They can be used alone or in combination of two or more.

[0030] Examples of the sulfenamide type include sulfenamide compounds such as CBS (N-cyclohexyl-2-benzothiazolylsulfenamide), TBBS (N-tert-butyl-2-benzothiazolylsulfenamide), N,N-dicyclohexyl-2-benzothiazolylsulfenamide, N-oxydiethylene-2-benzothiazolylsulfenamide, N,N-diisopropyl-2-benzothiazolesulfenamide, etc.

[0031] Examples of the thiazole type include MBT (2-mercaptobenzothiazole), MBTS (dibenzothiazolyl disulfide), the sodium salt, zinc salt, copper salt, cyclohexylamine salt of 2-mercaptobenzothiazole, 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-diethyl-4-morpholinothio)benzothiazole, etc.

[0032] Examples of the thiuram type include TMTD (tetramethylthiuram disulfide), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuram disulfide, dipentamethylenethiuram monosulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuram hexasulfide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide, etc.

[0033] Examples of the thiourea type include thiourea compounds such as thiocarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, di-o-tolylthiourea, etc.

[0034] Examples of the guanidine type include guanidine compounds such as diphenylguanidine, di-o-tolylguanidine, triphenylguanidine, o-tolylbiguanide, diphenylguanidine phthalate.

[0035] Examples of the dithiocarbamate type include zinc ethylphenyl dithiocarbamate, zinc butylphenyl dithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc dipentyldithiocarbamate, zinc dipropyldithiocarbamate, the coordination salt of zinc pentamethylenedithiocarbamate and piperidine, zinc cetylisopropyl dithiocarbamate, zinc octadecylisopropyl dithiocarbamate, zinc dibenzyldithiocarbamate, sodium diethyldithiocarbamate, piperidine pentamethylenedithiocarbamate, selenium dimethyldithiocarbamate, tellurium diethyldithiocarbamate, cadmium dipentyldithiocarbamate, etc.

[0036] Examples of the aldehyde-amine type or aldehyde-ammonia type include the reaction product of acetaldehyde and aniline, the condensate of butyraldehyde and aniline, hexamethylenetetramine, the reaction product of acetaldehyde and ammonia, etc.

[0037] Preferably, the accelerator is accelerator CBS and accelerator TMTD. The amount of accelerator CBS is 0.5 - 1.0 parts, and the amount of accelerator TMTD is 1.0 - 2.0 parts.

[0038] There is no particular limitation on the type of antioxidant, and commonly used antioxidants can be used. Examples include amine-based, phenolic, and heterocyclic antioxidants, which can be used alone or in combination of two or more.

[0039] Examples of amine-based antioxidants include N-phenyl-N'-isopropyl-p-phenylenediamine (4010NA), N-phenyl-N'-sec-butyl-p-phenylenediamine (4020), N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine (6PPD), N-cyclohexyl-N'-phenyl-p-phenylenediamine (CPPD), condensate of p-phenylenediamine and diphenylamine (H-8), condensate of p-phenylenediamine and acetone (AP), 4-aminodiphenylamine (RT base), N-(1-methylheptyl)-N'-phenyl-p-phenylenediamine (7PPD), N-(1-methylheptyl)-N'-(4-chlorophenyl)-p-phenylenediamine (7PCPD), N-(1-methylheptyl)-N'-(3-chlorophenyl)-p-phenylenediamine (7MCPD), etc.

[0040] Examples of phenolic antioxidants include 2,6-di-tert-butyl-4-methylphenol (BHT), pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (1010), tris(2,4-di-tert-butylphenyl) phosphite (168), 2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P), 2-(2-hydroxy-4-methoxyphenyl) benzotriazole (UV-9), etc.

[0041] Examples of heterocyclic antioxidants include benzimidazole-2-thiol (MBI), zinc salt of benzimidazole-2-thiol (MBZ), 2-(2-hydroxyphenyl) benzimidazole (HPBI), 2-(2-aminophenyl) benzimidazole (APBI), 2-(2-methoxyphenyl) benzimidazole (MPBI), 2-(2-dodecyloxyphenyl) benzimidazole (DDPI), 2-(2-benzyloxyphenyl) benzimidazole (BOPI), 2-(2-phenoxyphenyl) benzimidazole (POPI), etc.

[0042] The type of softening agent is not particularly limited, and commonly used softening agents can be used. Examples of softening agents include petroleum-based softening agents such as processing oil, lubricating oil, paraffin wax, liquid paraffin, petroleum pitch, and petrolatum; fatty oil-based softening agents such as castor oil, linseed oil, rapeseed oil, and coconut oil; waxes such as tall oil, substitution paste, beeswax, carnauba wax, and lanolin; and fatty acids such as linoleic acid, palmitic acid, stearic acid, and lauric acid. They can be used alone or in combination of two or more. By incorporating a softening agent, the kneading processability can be further improved.

[0043] The type of anti-scorching agent is not particularly limited, and commonly used anti-scorching agents can be used. Examples of anti-scorching agents include organic acids such as phthalic anhydride, salicylic acid, and benzoic acid; nitroso compounds such as N-nitrosodiphenylamine; and N-cyclohexylthiophthalimide. They can be used alone or in combination of two or more.

[0044] The present invention provides a high-temperature resistant tread rubber composition for new energy vehicle tires. By adding an unsaturated polyester resin and liquid cis-1,4-polybutadiene rubber for crosslinking reaction, the wear resistance, thermal stability, and overall performance of the tires are effectively improved, and it is suitable for the manufacture of tires for new energy sedans. Detailed implementation mode

[0045] The following combines the embodiments of the present invention, and clearly and completely describes the technical solutions in the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0046] Table 1 Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 NR 60 60 60 50 60 60 SBR 40 40 40 50 40 40 Unsaturated polyester resin 12 10 15 12 20 12 Liquid cis-1,4-polybutadiene rubber 20 15 25 20 30 20 Carbon black 20 20 20 30 20 20 Silica 10 10 10 5 10 10 Sulfur 2 2 2 2 2 2 Dimethyl phthalate 10 8 12 10 10 10 Zinc oxide 5 5 5 5 5 5 Stearic acid 2 2 2 2 2 2 Antioxidant 6PPD 3 3 3 3 3 3 Accelerator CBS 1.5 1.5 1.5 1.5 1.5 1.5 Accelerator TMTD 0.5 0.5 0.5 0.5 0.5 0.5 Raw material source: SBR: SBR1502, a product of Sinopec.

[0047] NR: Vietnam 3L.

[0048] Carbon black: N234, a product of Cabot.

[0049] Silica: HD165MP, Quesheng Chemical.

[0050] Example 1 The formulation is shown in Table 1. Among them, the unsaturated polyester resin used contains carboxyl groups, has an average molecular weight of 6000, and an unsaturation degree of 0.8; the liquid cis-1,4-polybutadiene rubber used is a terminal amino-modified liquid cis-1,4-polybutadiene rubber with a viscosity of 100 mPa·s.

[0051] The preparation method of the unsaturated polyester resin is as follows: 1) Esterification reaction: Ethylene glycol, adipic acid, trimellitic anhydride, and hydroquinone were added to a reaction vessel. The mass ratio of ethylene glycol, adipic acid, and trimellitic anhydride was 56:146:34, and the addition amount of hydroquinone was 0.05 - 0.1% of the total mass of the reactants. The stirring speed was set at 120 rpm, and nitrogen was introduced to displace the air. The temperature was raised to 180°C at a rate of 4°C / min, and the reaction was carried out at this temperature for 4 hours with continuous stirring. The water generated by the reaction was collected through a water separator. 2) Polycondensation reaction: After the esterification was completed, tetrabutyl titanate was added, and the addition amount of tetrabutyl titanate was 0.15 - 0.25% of the total mass of the reactants. The temperature was raised to 220°C, and at the same time, the pressure in the reaction vessel was gradually evacuated to 500 Pa, and the reaction was maintained under this condition for 5 hours. 3) Post-treatment: After the reaction was completed, it was cooled to 80°C, and an appropriate amount of toluene was added to dilute it to a suitable fluidity. Impurities that might exist were removed by filtration to obtain unsaturated polyester resin. [[ID=G]]

[0052] The preparation method of liquid cis-1,4-polybutadiene rubber is as follows: 1) Modification reaction: Unmodified liquid cis-1,4-polybutadiene rubber (BR9000, Dushanzi Petrochemical) and toluene with a mass ratio of 2:1 were added to a reaction vessel and stirred at 60°C to dissolve it. Azobisisobutyronitrile was added and stirring was continued to disperse it. Then, ethylenediamine was slowly added dropwise at a rate of 2 - 3 drops / second. The mass ratio of unmodified liquid cis-1,4-polybutadiene rubber to ethylenediamine was 25:2. After the addition was completed, the reaction was continued at 70°C for 6 hours with a stirring speed of 120 rpm maintained during this period. 2) Post-treatment: After the reaction was completed, the toluene solvent was removed at 50°C and a vacuum degree of 0.09 MPa. Then, the product was dissolved in an appropriate amount of acetone, slowly poured into an excess of methanol for precipitation, and dried in a vacuum drying oven at 50°C after filtration to obtain end-amino modified liquid cis-1,4-polybutadiene rubber.

[0053] Example 2 The formulation is shown in Table 1. Among them, the unsaturated polyester resin used contains carboxyl groups, has an average molecular weight of 8000, and an unsaturation degree of 0.5; the liquid cis-1,4-polybutadiene rubber used is end-amino modified liquid cis-1,4-polybutadiene rubber with a viscosity of 100 mPa·s.

[0054] The preparation method of the unsaturated polyester resin is the same as that in Example 1, and the mass ratio of ethylene glycol, adipic acid, and trimellitic anhydride is 47:121:72.

[0055] The preparation method of the liquid cis-1,4-polybutadiene rubber is the same as that in Example 1.

[0056] Example 3 The formulation is shown in Table 1. Among them, the unsaturated polyester resin used contains carboxyl groups, has an average molecular weight of 10,000, and an unsaturation of 0.8; the liquid cis-1,4-polybutadiene rubber used is an end-amino modified liquid cis-1,4-polybutadiene rubber with a viscosity of 100 mPa·s.

[0057] The preparation method of the unsaturated polyester resin is the same as that in Example 1, and the mass ratio of ethylene glycol, adipic acid, and trimellitic anhydride is 62:153:154.

[0058] The preparation method of the liquid cis-1,4-polybutadiene rubber is the same as that in Example 1.

[0059] Comparative Example 1 The formulation is shown in Table 1. Among them, the unsaturated polyester resin used contains carboxyl groups, has a molecular weight of 6,000, and an unsaturation of 0.5; the liquid cis-1,4-polybutadiene rubber used is not modified (BR9000, Dushanzi Petrochemical), does not contain amino groups at the end, and has a viscosity of 200 mPa·s. In order to match the properties and addition amounts of the unsaturated polyester resin and the liquid cis-1,4-polybutadiene rubber, the addition amount of NR is 50 parts, the addition amount of SBR is 50 parts, the addition amount of carbon black is 30 parts, and the addition amount of silica is 5 parts.

[0060] The preparation method of the unsaturated polyester resin is the same as that in Example 1.

[0061] Comparative Example 2 The formulation is shown in Table 1. Among them, the unsaturated polyester resin used contains carboxyl groups, has a molecular weight of 8,000, and an unsaturation of 0.5; the liquid cis-1,4-polybutadiene rubber used is an end-amino modified liquid cis-1,4-polybutadiene rubber with a viscosity of 100 mPa·s. The addition amount of the unsaturated polyester resin is 20 parts, and the addition amount of the liquid cis-1,4-polybutadiene rubber is 30 parts.

[0062] The preparation methods of the unsaturated polyester resin and the liquid cis-1,4-polybutadiene rubber are the same as those in Example 1.

[0063] Comparative Example 3 The formulation is shown in Table 1. Among them, the unsaturated polyester resin used contains carboxyl groups, has an average molecular weight of 12,000, and an unsaturation of 0.5; the liquid cis-1,4-polybutadiene rubber used is an end-amino modified liquid cis-1,4-polybutadiene rubber with a viscosity of 100 mPa·s.

[0064] The preparation method of the unsaturated polyester resin is as follows: 1) Esterification reaction: Add ethylene glycol, adipic acid, trimellitic anhydride, and hydroquinone into the reaction vessel. The mass ratio of ethylene glycol, adipic acid, and trimellitic anhydride is 43:113:43, and the addition amount of hydroquinone is 0.1 - 0.2% of the total mass of the reactants; set the stirring speed at 200 rpm, introduce nitrogen to displace air, and heat up to 190°C at a rate of 4°C / min. React at this temperature for 5 hours, continuously stir during the reaction, and collect the water generated by the reaction through a water separator; 2) Polycondensation reaction: After the esterification is completed, tetrabutyl titanate is added, and the addition amount of tetrabutyl titanate is 0.25 - 0.35% of the total mass of the reactants; the temperature is raised to 230 °C, and at the same time, the pressure in the reaction vessel is gradually evacuated to 100 Pa, and the reaction is maintained under this condition for 8 hours; 3) Post-treatment: After the reaction is completed, it is cooled to 80 °C, and an appropriate amount of toluene is added to dilute it to a suitable fluidity, and the possible impurities are removed by filtration to obtain unsaturated polyester resin.

[0065] The preparation method of liquid cis-1,4-polybutadiene rubber is the same as that in Example 1.

[0066] The preparation methods of the tread rubber compositions of the examples and comparative examples are as follows: (1) Kneading stage: Kneading is carried out using a Banbury mixer. Natural rubber, cis-1,4-polybutadiene rubber, carbon black, and chemical additives are pre-kneaded. Here, the chemical additives do not include anti-aging agents, sulfur, and accelerators. The kneading time is 150 - 230 seconds, and the discharge temperature is 130 - 145 °C to obtain masterbatch; (2) Final kneading stage: Kneading is carried out using a Banbury mixer. The masterbatch, anti-aging agent, sulfur, and accelerator are kneaded. The kneading time is 60 - 180 seconds, and the discharge temperature is 95 - 105 °C to obtain the tread rubber composition.

[0067] Performance tests are carried out on the tread rubber compositions of the examples and comparative examples: 1) Abrasion resistance: Test is carried out using a DIN abrasion tester. The vulcanized rubber specimen is made into a cuboid with a length of 40 mm, a width of 20 mm, and a thickness of 6 mm, installed on the fixture of the tester, and tested at 100 °C, and the abrasion volume is recorded, with the unit of mm³.

[0068] 2) High-temperature stability: The tire rubber specimen is placed under the condition of 120 °C × 72 h for aging test, and the change in hardness before and after the test is observed.

[0069] 3) Anti-aging performance: The tire rubber specimen is placed under the condition of 120 °C × 200 h until cracks appear, and the crack generation situation before and after the test is observed.

[0070] 3) High-temperature resistant range: The tire sample is placed in a high-temperature environment of 80 °C - 120 °C for aging test, and the change in hardness and crack generation situation before and after the test are observed to determine its temperature-resistant range.

[0071] 4) Elastic modulus: Test is carried out using a dynamic mechanical analyzer (DMA).

[0072] The test results are shown in Table 2.

[0073] Table 2 Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Wear (mm³) 180 189 176 230 209 227　 Hardness change rate (%) 3 3.8 3.4 10 7 8 Anti-aging performance No crack No crack No crack More cracks More cracks More cracks High temperature resistant range (℃) 80-120 80-120 80-120 60-100 70-110 60-100 Elastic modulus (MPa) 2.5 2.4 2.4 2 2.3 2 Observing Table 2, it can be seen from Example 1 and Comparative Example 1 that after the crosslinking reaction of unsaturated polyester resin and liquid cis-butadiene rubber, the wear resistance and high-temperature stability of the tire tread rubber composition can be enhanced, and it has a higher high-temperature resistant range. This may be because the crosslinking reaction of unsaturated polyester resin and liquid cis-butadiene rubber promotes the formation of a more stable crosslinked structure in the rubber matrix. It can be seen from Example 1 and Comparative Example 2 that too high an input amount of unsaturated polyester resin and liquid cis-butadiene rubber does not bring better wear resistance and high-temperature stability. It can be seen from Example 1 and Comparative Example 3 that too high a molecular weight of unsaturated polyester resin does not bring better wear resistance and high-temperature stability.

[0074] The above is the description of the embodiments of the present invention. Through the above description of the disclosed embodiments, those skilled in the art can implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A heat-resistant tread rubber composition for new energy vehicle tires, characterized in that, The rubber composition is prepared by mixing the following raw materials based on 100 parts by weight of raw rubber: 40 - 60 parts of natural rubber, 40 - 60 parts of synthetic rubber, 5 - 45 parts of filler, 10 - 15 parts of unsaturated polyester resin, 15 - 25 parts of liquid cis-butadiene rubber, 0.5 - 2 parts of crosslinking agent, 5 - 15 parts of plasticizer; The unsaturated polyester resin has a carboxyl group in its molecular structure, an average molecular weight of 5000 - 10000, and an unsaturation range of 0.2 - 0.8; The liquid cis-butadiene rubber is a modified liquid cis-butadiene rubber with terminal amino groups and can react with the unsaturated polyester resin.

2. The tread rubber composition of a new energy vehicle tire with high temperature resistance according to claim 1, characterized in that, The viscosity of the liquid cis-butadiene rubber is 50 - 150 mPa•s.

3. The tread rubber composition of a new energy vehicle tire with high temperature resistance according to claim 1, characterized in that, The unsaturation range of the molecular structure of the unsaturated polyester resin is 0.4 - 0.

6.

4. A heat-resistant new energy vehicle tire tread rubber composition according to claim 1, characterized in that, The filler is carbon black and / or silica, 10 - 30 parts of carbon black and 5 - 15 parts of silica.

5. The tread rubber composition of a new energy vehicle tire with high temperature resistance according to claim 3, characterized in that, The filler is carbon black and silica, 20 - 30 parts of carbon black and 5 - 10 parts of silica.

6. The tread rubber composition of a new energy vehicle tire with high temperature resistance according to claim 1, characterized in that The crosslinking agent is sulfur and / or peroxide.

7. The tread rubber composition of a new energy vehicle tire with high temperature resistance according to claim 1, characterized in that, The plasticizer is phthalate, quaternary ammonium salt or fatty acid ester.

8. The tread rubber composition of a new energy vehicle tire with high temperature resistance according to claim 1, characterized in that, The rubber composition based on 100 parts by weight of raw rubber further includes the following raw materials: 1 - 5 parts of zinc oxide, 1 - 3 parts of stearic acid, 1 - 5 parts of antioxidant, and 0.5 - 2.5 parts of accelerator.

9. A heat-resistant new energy vehicle tire tread rubber composition according to claim 8, characterized in that, The accelerator is accelerator CBS and accelerator TMTD, 0.5 - 1.0 part of accelerator CBS and 1.0 - 2.0 parts of accelerator TMTD.