Tire with improved wet land gripping performance in later stage of abrasion
By adding sodium sulfate to the inner tread rubber composition of the tire, micropores are formed to improve drainage efficiency and friction coefficient, solving the problem of decreased wet grip performance in the later stages of wear and achieving improved grip performance under wet conditions.
Patent Information
- Application Number
- CN202510986528.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-17
- Publication Date
- 2025-10-31
AI Technical Summary
Existing tires exhibit a significant decrease in wet grip performance in the later stages of wear, failing to continuously meet the demands of safe driving, and traditional methods are insufficient to effectively improve this.
The tire features a dual-layer tread design. Sodium sulfate with a particle size of 1–100 micrometers is added to the rubber composition of the inner tread. The water-soluble filler sodium sulfate dissolves rapidly after wear, forming micropores to improve drainage efficiency and the coefficient of friction.
It significantly improves tire grip performance in wet conditions, enhances safety, and does not affect the mixing properties of the rubber composition.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of tire rubber manufacturing technology, and more specifically, to a tire with improved wet grip performance in the later stages of wear. Background Technology
[0002] Over time, car tires experience gradual wear and tear on their treads, resulting in a significant decrease in their initially designed wet grip performance and increased driving safety risks. Traditional tires use a single-compound tread structure, and once they wear down to a certain extent, their wet grip performance declines rapidly, failing to continuously meet the vehicle's safe driving requirements.
[0003] Existing technologies attempt to improve overall tire wet grip performance throughout its lifespan by increasing the proportion of silica, using highly dispersed silica, and modifying rubber with resins. However, these technologies typically cannot overcome the significant performance degradation that occurs after severe tread wear, especially in wet conditions where there is still a noticeable performance deficiency, failing to provide effective long-term safety assurance.
[0004] In addition, a few studies have attempted to address the significant performance degradation with wear through double or multi-layer tread designs. However, these designs are usually limited to the stacking of rubber layers with different hardness, lacking clear structural innovation and functional differences, and are unlikely to significantly improve wet grip performance in the later stages of wear.
[0005] Therefore, there is an urgent need for a new tire tread material that can effectively and significantly improve wet grip performance in the later stages of tire tread wear, making up for the shortcomings of existing technologies. Summary of the Invention
[0006] This invention addresses the shortcomings of existing technologies by providing a tire with improved wet grip performance in the later stages of wear.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: A tire with improved wet grip performance in the later stages of wear, the tire tread comprising a double-layer tread rubber, wherein the inner tread rubber composition contains sodium sulfate, the sodium sulfate having a particle size of 1-100 micrometers, and the amount of sodium sulfate added is 5-30 parts by weight per 100 parts by weight of raw rubber.
[0008] According to claim 1, the tire with improved wet grip performance in the later stages of wear is characterized in that the thickness of the inner tread layer is 1.5 to 3.0 mm.
[0009] Preferably, the inner tread rubber composition is prepared by mixing raw materials comprising the following components: 70-90 parts by weight of solution-polymerized styrene-butadiene rubber. 10-30 parts by weight of natural rubber 50-80 parts by weight of silica Carbon black 0.5-10 parts by weight, Sodium sulfate 5.0–30 parts by weight; The glass transition temperature of the solution-polymerized styrene-butadiene rubber is -10℃ to -40℃, and the vinyl content is ≥50%.
[0010] Preferably, the inner tread rubber composition is prepared by mixing raw materials comprising the following components: 70-90 parts by weight of solution-polymerized styrene-butadiene rubber. 10-30 parts by weight of natural rubber 50-80 parts by weight of silica Carbon black 0.5-10 parts by weight, Sodium sulfate 10-20 parts by weight, Zinc oxide 2.0–5.0 parts by weight, Stearic acid 1.0–3.0 parts by weight, Anti-aging agent 1.0-5.0 parts by weight, Accelerator 0.5–3.5 parts by weight, Vulcanizing agent 1.0 to 3.0 parts by weight, 4.0 to 10 parts by weight of silane coupling agent.
[0011] Preferably, the antioxidant is antioxidant 6PPD.
[0012] Preferably, the accelerator is accelerator CZ and accelerator TBzTD, wherein accelerator CZ is 1.5 to 3.0 parts by weight and accelerator TBzTD is 0.1 to 0.5 parts by weight.
[0013] Preferably, the silane coupling agent is Si-69.
[0014] Preferably, the method for mixing the inner tread rubber composition includes the following steps: 1) Mixing section: The internal mixer is used to mix solution-polymerized styrene-butadiene rubber, natural rubber, silica, carbon black, and chemical additives. The chemical additives here do not include antioxidants, sulfur, and accelerators. The mixing temperature is 140-160℃ and the mixing time is 1-4 minutes. 2) Final mixing stage: The masterbatch, antioxidant, sulfur and accelerator are mixed using an internal mixer for 1 to 2 minutes. The discharge temperature is 95 to 105°C and the inner tread thickness is controlled at 1.5-3.0 mm to obtain the inner tread rubber composition.
[0015] Preferably, the inner tread rubber composition has a vulcanization temperature of 150-170°C, a vulcanization time of 10-20 minutes, and a vulcanization pressure of 15-25 bar.
[0016] This invention provides a tire with improved wet grip performance in the later stages of wear. The tire tread includes a double-layer tread rubber, wherein the inner tread rubber composition contains sodium sulfate with a particle size of 1-100 micrometers. In the later stages of wear of the outer tread, the water-soluble filler sodium sulfate dissolves rapidly upon contact with water, and micropores are actively generated on the surface of the inner tread rubber, forming a "micro-suction cup effect" with the road surface, which significantly improves drainage efficiency and road friction coefficient, thereby greatly improving wet grip performance. Moreover, the addition of sodium sulfate has virtually no impact on the mixing and other properties of the inner tread rubber composition. Detailed Implementation
[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention.
[0018] The inner tread compound of this application improves wet grip performance after the outer tread compound wears down by adding water-soluble fillers to a suitable inner tread rubber composition. The materials in the formulation are not particularly limited and are conventionally available.
[0019] There are no particular limitations on the type of carbon black used; any commonly used carbon black can be employed. Examples include furnace black, thermal black, acetylene black, and Ketjen black. Among these, furnace black is preferred from the viewpoint of further improving the mechanical strength of the rubber composition. One type can be used alone, or two or more can be used in combination. Furthermore, to further improve the affinity with the rubber components, organic treatments can be applied to the surface.
[0020] As for silica, it refers to silica-silicic acid based filler materials, not just silica in the narrow sense. There is no particular limitation, and it can be appropriately selected from existing materials used as reinforcing fillers. Examples include wet silica (hydrated silica) and dry silica (anhydrous silica). Among these, wet silica is preferred from the viewpoint of further improving processability, anti-slip properties, and wear resistance. One type can be used alone, or two or more can be used in combination. Furthermore, to further improve affinity with rubber components, it is preferable to form a treatment layer of a surface treatment agent on the surface.
[0021] There are no particular limitations on antioxidants; commonly used antioxidants can be used. Examples include amines, phenols, and heterocyclic antioxidants. They can be used alone or in combination of two or more.
[0022] Examples of amine 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), the condensate of p-phenylenediamine and diphenylamine (H-8), the condensate of p-phenylenediamine and acetone (AP), 4-aminodiphenylamine (RT-Plast), N-(1-methylheptyl)-N'-phenyl-p-phenylenediamine (7PPD), N-(1-methylheptyl)-N'-(4-chlorophenyl)-p-phenylenediamine (7PCPD), and N-(1-methylheptyl)-N'-(3-chlorophenyl)- p-phenylenediamine (7MCPD), etc.
[0023] Examples of phenolic antioxidants include 2,6-di-tert-butyl-4-methylphenol (BHT), pentaerythritol tetrakis[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), and 2-(2-hydroxy-4-methoxyphenyl)benzotriazole (UV-9).
[0024] Examples of heterocyclic antioxidants include 2-mercaptobenzimidazole (MBI), zinc 2-mercaptobenzimidazole (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), and 2-(2-phenoxyphenyl)benzimidazole (POPI).
[0025] Among them, the preferred antioxidant is 6PPD.
[0026] There are no particular limitations on the use of vulcanization accelerators; commonly used vulcanization accelerators can be used. Examples include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamate, aldehyde-amine, or aldehyde-amine accelerators. These can be used alone or in combination of two or more.
[0027] Examples of sulfonamide compounds include CBS (N-cyclohexyl-2-benzothiazolyl sulfonamide), TBBS (N-tert-butyl-2-benzothiazolyl sulfonamide), N,N-dicyclohexyl-2-benzothiazolyl sulfonamide, N-oxodiethylidene-2-benzothiazolyl sulfonamide, and N,N-diisopropyl-2-benzothiazolyl sulfonamide.
[0028] Examples of thiazole derivatives include MBT (2-mercaptobenzothiazole), MBTS (dibenzothiazole disulfide), sodium salt, zinc salt, copper salt, cyclohexylamine salt of 2-mercaptobenzothiazole, 2-(2,4-dinitrophenyl)mercaptobenzothiazole, and 2-(2,6-diethyl-4-morpholinothio)benzothiazole.
[0029] As a thiuram series, examples include TMTD (tetramethylthiuram disulfide), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, diamylene thiuram disulfide, diamylene thiuram monosulfide, diamylene thiuram tetrasulfide, diamylene thiuram hexasulfide, dibutylthiuram disulfide, and diamylene thiuram tetrasulfide.
[0030] As a thiourea group, examples include thiocarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, di-o-tolylthiourea, and other thiourea compounds.
[0031] As guanidine compounds, examples include diphenylguanidine, di-o-toluidine, triphenylguanidine, o-toluidine, and diphenylguanidine phthalate.
[0032] Examples of dithiocarbamate compounds include zinc ethylphenyl dithiocarbamate, zinc butylphenyl dithiocarbamate, sodium dimethyl dithiocarbamate, zinc dimethyl dithiocarbamate, zinc diethyl dithiocarbamate, zinc dibutyl dithiocarbamate, zinc dipentyl dithiocarbamate, zinc dipropyl dithiocarbamate, a coordination salt of zinc pentamethylene dithiocarbamate and piperidine, zinc hexadecyl isopropyl dithiocarbamate, zinc octadecyl isopropyl dithiocarbamate, zinc dibenzyl dithiocarbamate, sodium diethyl dithiocarbamate, piperidine pentamethylene dithiocarbamate, selenium dimethyl dithiocarbamate, tellurium diethyl dithiocarbamate, and cadmium dipentyl dithiocarbamate.
[0033] Examples of aldehyde-amine or aldehyde-amine compounds include acetaldehyde-aniline reactants, butyraldehyde-aniline condensates, hexamethylenetetramine, and acetaldehyde-amine reactants.
[0034] Among them, the preferred accelerators are accelerator CZ and accelerator TBzTD.
[0035] There are no particular limitations on the vulcanizing agents used, but examples include benzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, tert-butylcumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, 2,5-dimethyl-2,5-di(benzoylperoxide)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexyn-3, 1,3-bis(tert-butylperoxidepropyl)benzene, di-tert-butylperoxide diisopropylbenzene, tert-butylperoxidebenzene, 2,4-dichlorobenzoyl peroxide, 1,1-di-tert-butylperoxide-3,3,5-trimethylsiloxane, 4,4-di-tert-butylperoxyvalerate n-butyl ester, vulcanizate, and morpholine disulfide. These vulcanizing agents can be used alone or in combination of two or more, with sulfur being the preferred choice.
[0036] There are no particular limitations on silane coupling agents; examples include sulfide-based, polysulfide-based, thioester-based, thiol-based, olefin-based, epoxy-based, amino-based, and alkyl-based silane coupling agents. They can be used individually or in combination of two or more. Among these, sulfide-based silane coupling agents and amino-based silane coupling agents are preferred.
[0037] Examples of silane coupling agents based on sulfide systems 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-triethoxysilylpropyl)trisulfide, bis(3-trimethoxysilylpropyl)trisulfide, and bis(3-methyldimethoxysilylpropyl)tetrasulfide. Propyl trisulfide, bis(2-triethoxysilylethyl) trisulfide, bis(3-monoethoxydimethylsilylpropyl) tetrasulfide, bis(3-monoethoxydimethylsilylpropyl) trisulfide, bis(3-monoethoxydimethylsilylpropyl) disulfide, bis(3-monoethoxydimethylsilylpropyl) tetrasulfide, bis(3-monoethoxydimethylsilylpropyl) trisulfide, bis(3-monoethoxydimethylsilylpropyl) disulfide, bis(2-monoethoxydimethylsilylethyl) tetrasulfide, bis(2-monoethoxydimethylsilylethyl) trisulfide, bis(2-monoethoxydimethylsilylethyl) disulfide, etc. Among these, bis(3-triethoxysilylpropyl) tetrasulfide is preferred.
[0038] Examples of thioester-based silane coupling agents include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, 3-lauroylthiopropyltriethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, and 2-lauroylthioethyltriethoxysilane. Triethoxysilane, 3-hexanoylthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octanoylthioethyltrimethoxysilane, 2-decanoylthioethyltrimethoxysilane, 2-lauroylthioethyltrimethoxysilane, etc.
[0039] Examples of thiol-based silane coupling agents include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropylmethyldimethoxysilane.
[0040] Examples of olefin-based silane coupling agents 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, and 3-[tris(trimethylsiloxy)silyl]propyl methacrylate.
[0041] Examples of epoxy-based silane coupling agents include 3-epoxypropoxypropyl(dimethoxy)methylsilane, 3-epoxypropoxypropyltrimethoxysilane, diethoxy(3-epoxypropoxypropyl)methylsilane, triethoxy(3-epoxypropoxypropyl)silane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.
[0042] Examples of amino-based silane coupling agents include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-ethoxysilyl-N-(1,3-dimethylbutylene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane. Among these, 3-aminopropyltriethoxysilane is preferred.
[0043] Examples of alkyl-based silane coupling agents include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, and n-decyltrimethoxysilane.
[0044] Among them, Si-69 is preferred.
[0045] Example 1 A tire inner tread rubber composition formulation for improving wet grip performance in the later stages of wear: 80 parts by weight of solution-polymerized styrene-butadiene rubber, 20 parts by weight of natural rubber, 50 parts by weight of silica, 8.0 parts by weight of carbon black, 10 parts by weight of sodium sulfate, 3.0 parts by weight of zinc oxide, 2.0 parts by weight of stearic acid, 3.0 parts by weight of antioxidant 6PPD, 1.5 parts by weight of accelerator CZ, 0.5 parts by weight of accelerator TBzTD, 3.0 parts by weight of sulfur, and 6.0 parts by weight of Si-69.
[0046] Example 2 A tire inner tread rubber composition formulation for improving wet grip performance in the later stages of wear: 80 parts by weight of solution-polymerized styrene-butadiene rubber, 20 parts by weight of natural rubber, 50 parts by weight of silica, 8.0 parts by weight of carbon black, 15 parts by weight of sodium sulfate, 3.0 parts by weight of zinc oxide, 2.0 parts by weight of stearic acid, 3.0 parts by weight of antioxidant 6PPD, 1.5 parts by weight of accelerator CZ, 0.5 parts by weight of accelerator TBzTD, 3.0 parts by weight of sulfur, and 6.0 parts by weight of Si-69.
[0047] The difference from Example 1 is that 15 parts by weight of sodium sulfate were added.
[0048] Example 3 A tire inner tread rubber composition formulation for improving wet grip performance in the later stages of wear: 80 parts by weight of solution-polymerized styrene-butadiene rubber, 20 parts by weight of natural rubber, 50 parts by weight of silica, 8.0 parts by weight of carbon black, 20 parts by weight of sodium sulfate, 3.0 parts by weight of zinc oxide, 2.0 parts by weight of stearic acid, 3.0 parts by weight of antioxidant 6PPD, 1.5 parts by weight of accelerator CZ, 0.5 parts by weight of accelerator TBzTD, 3.0 parts by weight of sulfur, and 6.0 parts by weight of Si-69.
[0049] The difference from Example 1 is that 20 parts by weight of sodium sulfate were added.
[0050] Comparative Example 1 A tire inner tread rubber composition formulation: 80 parts by weight of solution-polymerized styrene-butadiene rubber, 20 parts by weight of natural rubber, 50 parts by weight of silica, 8.0 parts by weight of carbon black, 3.0 parts by weight of zinc oxide, 2.0 parts by weight of stearic acid, 3.0 parts by weight of antioxidant 6PPD, 1.5 parts by weight of accelerator CZ, 0.5 parts by weight of accelerator TBzTD, 3.0 parts by weight of sulfur, and 6.0 parts by weight of Si-69.
[0051] The difference from Example 1 is that sodium sulfate is not added.
[0052] Comparative Example 2 A tire inner tread rubber composition formulation: 80 parts by weight of solution-polymerized styrene-butadiene rubber, 20 parts by weight of natural rubber, 50 parts by weight of silica, 8.0 parts by weight of carbon black, 22 parts by weight of sodium sulfate, 3.0 parts by weight of zinc oxide, 2.0 parts by weight of stearic acid, 3.0 parts by weight of antioxidant 6PPD, 1.5 parts by weight of accelerator CZ, 0.5 parts by weight of accelerator TBzTD, 3.0 parts by weight of sulfur, and 6.0 parts by weight of Si-69.
[0053] The difference from Example 1 is that 22 parts by weight of sodium sulfate were added.
[0054] The mixing method for the inner tread rubber composition is as follows: 1) Mixing section: The internal mixer is used to mix solution-polymerized styrene-butadiene rubber, natural rubber, silica, carbon black, and chemical additives. The chemical additives here do not include antioxidants, sulfur, and accelerators. The mixing temperature is 140-160℃ and the mixing time is 3 minutes. 2) Final mixing stage: The masterbatch, antioxidant, sulfur and accelerator are mixed in an internal mixer for 2 minutes. The discharge temperature is 95-105℃ and the inner tread thickness is controlled at 2.0mm to obtain the inner tread rubber composition.
[0055] The inner tread rubber composition has a vulcanization temperature of 160℃, a vulcanization time of 15 minutes, and a vulcanization pressure of 20 bar.
[0056] Performance tests were conducted on the inner tread rubber compositions of the examples and comparative examples: 1) Wet grip performance (BPST, μ): Pendulum wet grip performance test (BPST); 2) Abrasion resistance: Tested using a standard abrasion tester.
[0057] 3) Rolling resistance: Tested using a Dynamic Mechanical Analyzer (DMA).
[0058] 4) Payne effect: Tested using a rubber processing analyzer (RPA).
[0059] The test results are shown in Table 1.
[0060] Table 1 As can be seen from Table 1, the addition of sodium sulfate has virtually no impact on the mixing and performance of the inner tread rubber composition, and can effectively improve the wet grip performance of the inner tread rubber.
[0061] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.
Claims
1. A tire with improved wet grip performance in the later stages of wear, characterized in that, The tire tread comprises a double-layer tread rubber, wherein the inner tread rubber composition contains sodium sulfate, the sodium sulfate having a particle size of 1 to 100 micrometers, and the amount of sodium sulfate added is 5 to 30 parts by weight per 100 parts by weight of raw rubber.
2. The tire with improved wet grip performance in the later stages of wear according to claim 1, characterized in that, The thickness of the inner tread layer is 1.5 to 3.0 mm.
3. The tire with improved wet grip performance in the later stages of wear according to claim 1, characterized in that, The inner tread rubber composition is prepared by mixing the following raw materials: Solution-polymerized styrene-butadiene rubber (SBR) 70–90 phr Natural rubber 10-30 phr 50-80 phr of silica Carbon black 0.5–10 phr Sodium sulfate 5.0–30 phr; The glass transition temperature of the solution-polymerized styrene-butadiene rubber is -10℃ to -40℃, and the vinyl content is ≥50%.
4. The tire with improved wet grip performance in the later stages of wear according to claim 3, characterized in that, The inner tread rubber composition is prepared by mixing the following raw materials: 70-90 parts by weight of solution-polymerized styrene-butadiene rubber. 10-30 parts by weight of natural rubber 50-80 parts by weight of silica Carbon black 0.5-10 parts by weight, Sodium sulfate 10-20 parts by weight, Zinc oxide 2.0–5.0 parts by weight, Stearic acid 1.0–3.0 parts by weight, Anti-aging agent 1.0-5.0 parts by weight, Accelerator 0.5–3.5 parts by weight, Vulcanizing agent 1.0 to 3.0 parts by weight, 4.0 to 10 parts by weight of silane coupling agent.
5. The tire with improved wet grip performance in the later stages of wear according to claim 4, characterized in that, The antioxidant is antioxidant 6PPD.
6. The tire with improved wet grip performance in the later stages of wear according to claim 4, characterized in that, The accelerator is accelerator CZ and accelerator TBzTD, with accelerator CZ at 1.5 to 3.0 parts by weight and accelerator TBzTD at 0.1 to 0.5 parts by weight.
7. The tire with improved wet grip performance in the later stages of wear according to claim 4, characterized in that, The vulcanizing agent is sulfur.
8. A tire with improved wet grip performance in the later stages of wear, as described in claim 4, characterized in that, The silane coupling agent is Si-69.
9. A tire with improved wet grip performance in the later stages of wear, as described in any one of claims 4-7, characterized in that, The method for mixing the inner tread rubber composition includes the following steps: 1) Mixing section: The internal mixer is used to mix solution-polymerized styrene-butadiene rubber, natural rubber, silica, carbon black, and chemical additives. The chemical additives here do not include antioxidants, sulfur, and accelerators. The mixing temperature is 140-160℃ and the mixing time is 1-4 minutes. 2) Final mixing stage: The masterbatch, antioxidant, sulfur and accelerator are mixed using an internal mixer for 1 to 2 minutes. The discharge temperature is 95 to 105°C and the inner tread thickness is controlled at 1.5-3.0 mm to obtain the inner tread rubber composition.
10. A tire with improved wet grip performance in the later stages of wear, as described in any one of claims 4-7, characterized in that, The inner tread rubber composition has a vulcanization temperature of 150-170℃, a vulcanization time of 10-20 minutes, and a vulcanization pressure of 15-25 bar.