An asymmetric tire tread with a tread band

Abstract

This invention relates to the application fields of tires, rubber, and other industries, and discloses an asymmetric tire tread compound with different tread rubbers and a tire using this structure. The asymmetric tire tread compound with different tread rubbers includes a tread compound, a base compound, a shoulder compound, and a conductive adhesive. The tread compound comprises an outer tread compound and an inner tread compound, arranged sequentially from left to right. The tread compound and the base compound are arranged sequentially from the outside to the inside to form the tread layer. The shoulder compound is located on both lateral sides of the tread layer, and the conductive adhesive is located at the center of the tread layer, penetrating the tread compound and the base compound from the outside to the inside. Applying this to tires ensures that the outer tread of the asymmetric tire has strong grip and good handling stability, while the inner tread offers superior comfort. Overall, the dry and wet braking and handling performance of the tire is superior to that of traditional asymmetric treads.

Description

Technical Field

[0001] This invention relates to the field of tire technology, and more specifically, to an asymmetric tire tread with different rubber types. Background Technology

[0002] Traditional asymmetrical tread patterns correspond to the tread and shoulder structure forms ( Figure 1 The tire is primarily composed of four compounds: tread compound, base compound, shoulder compound, and conductive compound. The outer and inner tread compounds are the same type of compound. The tread is responsible for braking and wear resistance, handling comfort, and water drainage. The base compound is responsible for modulus transition and molding viscosity, reducing heat generation. The shoulder compound is responsible for flexural properties at the shoulder. The conductive compound is responsible for static electricity dissipation.

[0003] The applicant's Chinese invention patent application (Publication No.: CN114874510A, Publication Date: 2022-08-09) discloses a five-composite rubber structure for tire treads. This tread compound includes an upper tread compound, a lower tread compound, a base compound, a shoulder compound, and a conductive compound. The upper tread compound, lower tread compound, and base compound are arranged sequentially from the outside to the inside to form the tread layer. The upper tread compound uses a low rolling resistance and low heat generation rubber composition, while the lower tread compound uses a rubber composition with low rolling resistance, good handling, low wear, and tear resistance. The shoulder compound is located on both lateral sides of the tread layer, and the conductive compound is located on one side of the center of the tread layer, penetrating from the outside to the inside of the upper tread compound, lower tread compound, and base compound. This tread compound controls rolling resistance and handling through two different combinations of upper and lower tread compounds, and after vulcanization, it can provide a tire with low rolling resistance, high wet grip, and good handling performance.

[0004] As consumers' demands increase, high-performance asymmetric tread pattern tires for cars must not only ensure high wet braking performance and high wet handling performance, but also take into account the tire's comfort performance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an asymmetrical tire tread with different rubber types. The outer tread has strong grip and good handling stability, while the inner tread has ideal water drainage performance and high comfort. Overall, the dry and wet braking and handling performance of the tire is superior to that of traditional symmetrical treads.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An asymmetric tire tread with different rubber compounds is disclosed. The tread comprises a tread compound, a base compound, and a conductive compound. The tread compound is characterized by using different rubber compounds on its inner and outer sides. The outer tread compound is a rubber composition with high resistance to both dry and wet skids, high handling, and low rolling resistance. It has a Shore A hardness > 68 at laboratory room temperature, a 300% tensile stress > 11 MPa, a tanD ≥ 0.40 at 0°C, a tanD ≥ 0.20 at 20°C, a composite modulus E* ≥ 20 MPa at 20°C, and a tanD ≤ 0.13 at 60°C. The inner tread compound is a rubber composition with high comfort properties. It has a Shore A hardness of 63-68 at laboratory room temperature, a 300% tensile stress of 9.0-11 MPa, a tanD of 0.3-0.40 at 0°C, a tanD of 0.18-0.22 at 20°C, and a composite modulus E* of 15-20 MPa at 20°C. The outer and inner tread compounds have the same thickness.

[0008] Preferably, the thickness of the outer tread compound and the inner tread compound is 5.0-6.0 mm.

[0009] Preferably, the outer tread rubber composition is prepared by mixing raw materials comprising the following components based on 100 parts by weight of raw rubber:

[0010] Natural rubber or butadiene rubber 35-55 phr

[0011] Solution-polymerized styrene-butadiene rubber 45-65 phr

[0012] 100-120 phr of silica

[0013] Silane coupling agent 10-20 phr,

[0014] Poly(α-methylstyrene) resin 20-30 phr

[0015] Hydrogenated dicyclopentadiene resin 1-10 phr

[0016] In addition, appropriate amounts of oil-extended sulfur powder, vulcanization accelerator, zinc oxide, microcrystalline wax, environmentally friendly oil, stearic acid and antioxidants;

[0017] The solution-polymerized styrene-butadiene rubber has a number-average molecular weight (Mn) of 300,000 to 800,000, a weight-average molecular weight (Mw) of 500,000 to 1,000,000, a molecular weight distribution (Mw / Mn) of 1.5 to 2.5, and styrene accounts for 30% to 42% of the solution-polymerized styrene-butadiene rubber.

[0018] Preferably, the outer tread rubber composition is prepared by mixing raw materials comprising the following components based on 100 parts by weight of raw rubber:

[0019] 40-50 phr of natural rubber or butadiene rubber

[0020] Solution-polymerized styrene-butadiene rubber 50-60 phr

[0021] 105-115 phr silica

[0022] Silane coupling agent 12-18 phr,

[0023] Poly(α-methylstyrene) resin 22-18 phr

[0024] Hydrogenated dicyclopentadiene resin 4-6 phr,

[0025] Oil-extended sulfur powder 1.0-2.5 phr,

[0026] Vulcanization accelerator 1.0-5.0 phr,

[0027] Zinc oxide 1.0-4.0 phr,

[0028] Stearic acid 1.5-4.0 phr

[0029] Microcrystalline wax 1.0-4.0 phr

[0030] Environmentally friendly oil, 2.0-10.0 phr.

[0031] Anti-aging agent 2.0-5.0 phr.

[0032] Preferably, the specific surface area (CTAB) of the silica is 150-200; the molecular weight distribution (Mw / Mn) of the poly-α-methylstyrene resin is 4-5; and the molecular weight distribution (Mw / Mn) of the hydrogenated dicyclopentadiene resin is 3-4.

[0033] Preferably, the silane coupling agent is Si747 8-12 phr, Si75 or Si69 4-6 phr; the antioxidant is antioxidant TMQ 1.0-2.0 phr or antioxidant 6PPD 2.0-4.0 phr; the vulcanization accelerator is accelerator NS; and the oil-extended sulfur powder is 10% oil-extended.

[0034] Preferably, the inner tread rubber composition is prepared by mixing raw materials comprising the following components based on 100 parts by weight of raw rubber:

[0035] Solution-polymerized styrene-butadiene rubber 70-90 phr

[0036] Neodymium-based cis-butadiene rubber 10-30 phr

[0037] Carbon black 35-55 phr

[0038] 25-45 phr of silica

[0039] In addition, appropriate amounts of oil-extended sulfur powder, vulcanization accelerator, zinc oxide, microcrystalline wax, environmentally friendly oil, stearic acid and antioxidants;

[0040] The styrene in the solution-polymerized styrene-butadiene rubber is 30-42% of the total styrene-butadiene rubber, and the molecular weight of the neodymium-based cis-butadiene rubber is 380-460 kg / mol.

[0041] Preferably, the inner tread rubber composition is prepared by mixing raw materials comprising the following components based on 100 parts by weight of raw rubber:

[0042] Solution-polymerized styrene-butadiene rubber 75-85 phr

[0043] Neodymium-based cis-butadiene rubber 15-25 phr

[0044] Carbon black 40-50 phr

[0045] 30-40 phr of silica

[0046] Oil-extended sulfur powder 1.0-2.5 phr,

[0047] Vulcanization accelerator 1.0-5.0 phr,

[0048] Zinc oxide 1.0-4.0 phr,

[0049] Stearic acid 1.5-4.0 phr

[0050] Microcrystalline wax 1.0-4.0 phr

[0051] Environmentally friendly oil, 2.0-10.0 phr.

[0052] Anti-aging agent 2.0-5.0 phr.

[0053] Preferably, the carbon black has an oil absorption value of 100-120*10. -5 cm 3 / g, nitrogen adsorption surface area is 70-90m² 2 / g, iodine uptake value is 80-90g / kg, and total specific surface area is 75-85*10 3 m 2 / kg, with a coloring strength of 95-110%; the oil absorption value of the precipitated silica is 2-3.5cm. 3 / g, nitrogen adsorption surface area is 150-170m² 2 / g.

[0054] Preferably, the antioxidant is TMQ 1.0-2.0 phr and 6PPD 2.0-4.0 phr; the vulcanization accelerator is NS; and the oil-extended sulfur powder is 10% oil-extended.

[0055] Furthermore, the present invention provides an asymmetric tire with different tread rubbers, the tire including a tread, a sidewall and a shoulder, the shoulder connecting the tread and the sidewall, that is, the shoulder is located on both sides of the tread in the lateral direction; wherein, the tread adopts the above-mentioned tire tread, and the shoulder is composed of shoulder rubber.

[0056] The tire tread and shoulder forming method of the above-mentioned tire is as follows: the outer tread rubber, inner tread rubber, base rubber, shoulder rubber and conductive rubber are fed into the rubber inlet of their respective screw extruders, and then extruded through their respective screw extruders and flow channels. They are then pressed out through the pre-drilling component and arranged into a pre-set shape. Finally, they are all pressed out together through the extrusion die component to form the tire tread and shoulder.

[0057] The beneficial effects of the present invention are as follows: The present invention provides an asymmetric tire tread with different rubbers and applies it to the tire, which ensures that the outer tread of the asymmetric tire has strong grip and good handling stability, while the inner tread has strong comfort. The overall dry and wet braking and handling performance of the tire is better than that of traditional asymmetric tire treads. Attached Figure Description

[0058] Figure 1 This is a diagram illustrating the structural form of a traditional asymmetrical tread pattern tire.

[0059] Figure 2 This is a structural diagram of the asymmetric tread pattern of the present invention.

[0060] Figure 3 This is a cross-sectional view of the tire of the present invention.

[0061] Figure 4 This refers to the tread pattern of the tire of the present invention.

[0062] Figure reference numerals: 1-tread compound, 11-outer tread compound, 12-inner tread compound, 2-conductive adhesive, 3-base adhesive, 4-shoulder adhesive. Detailed Implementation

[0063] 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.

[0064] Example 1

[0065] An asymmetric tire tread with different rubber types is provided, such as... Figure 2As shown, the tread is composed of tread rubber 1, base rubber 3, and conductive rubber 2. The inner and outer sides of the tread rubber 1 are made of different rubbers. The outer tread rubber 11 is made of a rubber composition with high anti-slip properties, high handling performance, and low heat generation. The inner tread rubber 12 is made of a rubber composition with good drainage and high comfort. The outer tread rubber 11 and the inner tread rubber 12 have the same thickness. Preferably, the thickness of the outer tread rubber 11 and the inner tread rubber 12 is 5.0-6.0 mm.

[0066] The outer tread rubber composition 11 is prepared by mixing the following raw materials based on 100 parts by weight of raw rubber: natural rubber or butadiene rubber 45 phr, solution-polymerized styrene-butadiene rubber 55 phr, silica 110 phr, silane coupling agents Si747 10 phr, Si69 5 phr, poly-α-methylstyrene resin 25 phr, hydrogenated dicyclopentadiene resin 5 phr, oil-extended sulfur powder 1.5 phr, vulcanization accelerator NS 2.5 phr, zinc oxide 2.5 phr, stearic acid 2.5 phr, microcrystalline wax 2.0 phr, environmentally friendly oil 6.0 phr, antioxidant TMQ 1.5 phr, antioxidant 6PPD 2.0 phr.

[0067] Among them, the solution-polymerized styrene-butadiene rubber (SBR) has a number-average molecular weight (Mn) of 300,000-800,000, a weight-average molecular weight (Mw) of 500,000-1,000,000, and a molecular weight distribution (Mw / Mn) of 1.5-2.5. The styrene content in the solution-polymerized SBR is 30%-42%. The specific surface area (CTAB) of the silica is 150-200. The molecular weight distribution (Mw / Mn) of the polyα-methylstyrene resin is 4-5, and the molecular weight distribution (Mw / Mn) of the hydrogenated dicyclopentadiene resin is 3-4. The oil-extended sulfur powder is 10% oil-extended.

[0068] The inner tread rubber 12 composition is prepared by mixing the following raw materials based on 100 parts by weight of raw rubber: solution-polymerized styrene-butadiene rubber 80 phr, neodymium-based cis-butadiene rubber 20 phr, carbon black 45 phr, silica 35 phr, oil-extended sulfur powder 1.5 phr, vulcanization accelerator NS 2.5 phr, zinc oxide 2.5 phr, stearic acid 2.5 phr, microcrystalline wax 2.0 phr, environmentally friendly oil 6.0 phr, antioxidant TMQ 1.5 phr, and antioxidant 6PPD 2.0 phr.

[0069] In solution-polymerized styrene-butadiene rubber (SBR), styrene accounts for 30-42% of the total SBR, and neodymium-based cis-butadiene rubber has a molecular weight of 380-460 kg / mol; the carbon black oil absorption value is 100-120*10. -5 cm 3 / g, nitrogen adsorption surface area is 70-90m² 2 / g, iodine uptake value is 80-90g / kg, and total specific surface area is 75-85*10 3 m2 / kg, coloring strength is 95-110%; oil absorption value of silica is 2-3.5cm. 3 / g, nitrogen adsorption surface area is 150-170m² 2 / g; oil-extended sulfur powder with 10% oil content.

[0070] Example 2

[0071] This provides an asymmetric tire with different tread rubbers, and the tire cross-section is shown in the figure. Figure 3 As shown, the tread pattern structure is as follows Figure 4 As shown. The tire includes a tread, a sidewall, and a shoulder, with the shoulder connecting the tread and the sidewall, i.e., the shoulder is located on both lateral sides of the tread; wherein, the tread adopts the tire tread structure of the present invention as shown. Figure 2 As shown.

[0072] The tire tread and shoulder forming method is as follows: Outer tread compound 11, inner tread compound 12, base compound 3, shoulder compound 4, and conductive compound 2 are fed into their respective screw extruder inlets. After extrusion through their respective screw extruders and flow channels, they are pressed out through a pre-formed die and arranged into a pre-defined shape. Finally, they are all pressed together through an extrusion die to form the tread and shoulder as a single unit. The thickness of both the outer tread compound 11 and the inner tread compound 12 is 5.5 mm.

[0073] This patent allows for the compounding of five rubber compounds into a tire tread component through a composite extrusion process, requiring only adjustment of the extrusion channel. The process is simple. The five rubber compositions provided in this patent possess their own characteristics while also considering the synergistic effects of the five compounds. After compound extrusion, the five compounds undergo molding and vulcanization processes, resulting in cross-linking at the interfaces. Therefore, separation of the different rubber compounds will not occur in actual use.

[0074] The outer tread compound 11 and the inner tread compound 12 adopt the rubber compound formulation of Example 1.

[0075]

[0076] In Table 1 above, tensile strength and elongation at break: the higher the value, the better the rubber compound reinforcement; hardness: the higher the value, the higher the hardness; tanD at 0℃: characterizes the tread's wet skid resistance; tanD at 20℃: characterizes the dry skid resistance; composite modulus E* at 20℃: characterizes dry handling performance, the higher the value, the better the handling performance; tanD at 60℃: characterizes the tread's rolling resistance performance, the lower the value, the lower the rolling resistance performance.

[0077] Dynamic mechanical analyzer (DMA) test conditions (tensile mode): pre-strain 7%, dynamic strain 0.25%, 12HZ.

[0078] Comparative Example 1

[0079] A conventional asymmetric tread pattern tire, differing from Example 2 in that the tire tread uses the following... Figure 1 The traditional asymmetric tread pattern structure shown is used; the tread compound adopts the outer tread compound formulation of Example 1. Performance testing.

[0080] According to the relevant national standard testing methods, indoor performance tests were conducted on the tires of Example 2 and Comparative Example 1. All test results were calculated with the comparative example as the baseline of 100. The test value (relative value) = test value of Example 2 / test value of Comparative Example 1 × 100. The specific test results are shown in Table 2. The prototype tire was 245 / 45R19.

[0081]

[0082] As can be seen from the comparative examples and embodiments in Table 2 above, the tires in the embodiments have better dry and wet performance, better handling performance, and better comfort performance.

[0083] 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. An asymmetric tire tread of a tread cap, the tread being composed of a tread rubber, a base rubber and a conductive rubber, characterized in that, The inner and outer tread compounds are made of different rubbers. The outer tread compound uses a rubber composition with high resistance to dry and wet skids, high handling, and low rolling resistance. At laboratory room temperature, its Shore A hardness is >68, 300% tensile stress is >11 MPa, tanD ≥0.40 at 0℃, tanD ≥0.20 at 20℃, composite modulus E* ≥20 MPa at 20℃, and tanD ≤0.13 at 60℃. The inner tread compound uses a rubber composition with high comfort. At laboratory room temperature, its Shore A hardness is 63-68, 300% tensile stress is 9.0-11 MPa, tanD is 0.3-0.40 at 0℃, tanD is 0.18-0.22 at 20℃, and composite modulus E* is 15-20 MPa at 20℃. The thickness of the outer and inner tread compounds is the same. The outer tread rubber composition was prepared by mixing raw materials comprising the following components based on 100 parts by weight of raw rubber: Natural rubber or butadiene rubber 35-55 phr Solution-polymerized styrene-butadiene rubber 45-65 phr 100-120 phr of silica Silane coupling agent 10-20 phr, Poly(α-methylstyrene) resin 20-30 phr Hydrogenated dicyclopentadiene resin 1-10 phr The solution-polymerized styrene-butadiene rubber (SBR) contains appropriate amounts of oil-extended sulfur powder, vulcanization accelerator, zinc oxide, microcrystalline wax, environmentally friendly oil, stearic acid, and antioxidants. The number-average molecular weight (Mn) of the SBR is 300,000-800,000, the weight-average molecular weight (Mw) is 500,000-1,000,000, and the molecular weight distribution (Mw / Mn) is 1.5-2.

5. Furthermore, the styrene content in the SBR is 30%-42%. The inner tread rubber composition is prepared by mixing raw materials comprising the following components based on 100 parts by weight of raw rubber: Solution-polymerized styrene-butadiene rubber 70-90 phr Neodymium-based cis-butadiene rubber 10-30 phr Carbon black 35-55 phr 25-45 phr of silica In addition, appropriate amounts of oil-extended sulfur powder, vulcanization accelerator, zinc oxide, microcrystalline wax, environmentally friendly oil, stearic acid and antioxidants; The styrene in the solution-polymerized styrene-butadiene rubber is 30-42% of the total styrene-butadiene rubber, and the molecular weight of the neodymium-based cis-butadiene rubber is 380-460 kg / mol.

2. The tire tread of claim 1 wherein, The thickness of the outer and inner tread compounds is 5.0-6.0 mm; the outer tread compound has a Shore A hardness of 70-72 at laboratory room temperature, tanD≥0.22 at 20℃, and tanD≤0.11 at 60℃; the inner tread compound has a Shore A hardness of 64-66 at laboratory room temperature.

3. The tire tread of claim 1 wherein, The outer tread rubber composition was prepared by mixing raw materials comprising the following components based on 100 parts by weight of raw rubber: 40-50 phr of natural rubber or butadiene rubber Solution-polymerized styrene-butadiene rubber 50-60 phr 105-115 phr silica Silane coupling agent 12-18 phr, Poly(α-methylstyrene) resin 22-28 phr Hydrogenated dicyclopentadiene resin 4-6 phr, Oil-extended sulfur powder 1.0-2.5 phr, Vulcanization accelerator 1.0-5.0 phr, Zinc oxide 1.0-4.0 phr, Stearic acid 1.5-4.0 phr Microcrystalline wax 1.0-4.0 phr Environmentally friendly oil, 2.0-10.0 phr. Anti-aging agent 2.0-5.0 phr.

4. A tyre tread according to claim 1 or 3, characterised in that, In the raw materials of the outer tread rubber composition: the specific surface area (CTAB) of the silica is 150-200; the molecular weight distribution (Mw / Mn) of the poly-α-methylstyrene resin is 4-5; and the molecular weight distribution (Mw / Mn) of the hydrogenated dicyclopentadiene resin is 3-4.

5. The tire tread of claim 1 or 3, wherein, The raw materials of the outer tread rubber composition include: silane coupling agent of Si747 8-12 phr and Si75 or Si69 4-6 phr; antioxidant of TMQ 1.0-2.0 phr and antioxidant 6PPD 2.0-4.0 phr; vulcanization accelerator of NS; and oil-extended sulfur powder of 10% oil content.

6. The tire tread of claim 1 wherein, The inner tread rubber composition is prepared by mixing raw materials comprising the following components based on 100 parts by weight of raw rubber: Solution-polymerized styrene-butadiene rubber 75-85 phr Neodymium-based cis-butadiene rubber 15-25 phr Carbon black 40-50 phr 30-40 phr of silica Oil-extended sulfur powder 1.0-2.5 phr, Vulcanization accelerator 1.0-5.0 phr, Zinc oxide 1.0-4.0 phr, Stearic acid 1.5-4.0 phr Microcrystalline wax 1.0-4.0 phr Environmentally friendly oil, 2.0-10.0 phr. Anti-aging agent 2.0-5.0 phr.

7. A tyre tread according to claim 1 or 6, characterised in that, The raw materials of the inner tread rubber composition include: carbon black with an oil absorption value of 100-120*10. -5 cm 3 / g, nitrogen adsorption surface area is 70-90m² 2 / g, iodine uptake value is 80-90g / kg, and total specific surface area is 75-85*10 3 m 2 / kg, with a coloring strength of 95-110%; the oil absorption value of the precipitated silica is 2-3.5cm. 3 / g, nitrogen adsorption surface area is 150-170m² 2 / g.

8. A tyre tread according to claim 1 or 6, characterised in that, The raw materials of the inner tread rubber composition include: antioxidants TMQ 1.0-2.0 phr and antioxidant 6PPD 2.0-4.0 phr; the vulcanization accelerator is NS; and the oil-extended sulfur powder is 10% oil-extended.

9. An asymmetric tire of a tread band, characterized in that, The tire includes a tread, a sidewall, and a shoulder, with the shoulder connecting the tread and the sidewall, i.e., the shoulder is located on both lateral sides of the tread; wherein the tread adopts the tire tread described in any one of claims 1-8, and the shoulder is composed of shoulder rubber.

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