Rubber composition for improving tire chromaticity and preparation method thereof
By using chromatic carbon black with high visible light absorption properties and strong coloring ability in tire rubber compositions and optimizing the silica formulation, the problem of insufficient blackness in tires has been solved, and the appearance quality and performance of tires have been improved.
Patent Information
- Application Number
- CN202511350893.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-22
- Publication Date
- 2025-12-12
AI Technical Summary
In existing technologies, the low amount of carbon black in the silica formulation results in insufficient blackness of the tire appearance, which affects the visual appeal of the high-end tire market.
By using chromatic carbon black with high visible light absorption characteristics and strong coloring ability, and optimizing the white carbon black formulation system, combined with processing oil, coupling agent, activator and other components, a rubber composition is prepared through a specific mixing process to improve the dispersibility and coloring performance of carbon black in rubber.
It significantly improves the blackness and coloring performance of tires, enhances their appearance quality, and maintains the advantages of low rolling resistance and high wet skid performance of the silica formula, thereby improving the market competitiveness of finished tires.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of tire surface treatment technology, specifically to a rubber composition for improving tire color and its preparation method. Background Technology
[0002] Currently, the tire industry commonly uses conventional Tint-value carbon black as a reinforcing filler for rubber, as its excellent main chain modification properties can significantly improve the mechanical properties of rubber products. This type of carbon black exhibits good dynamic and static properties and initial fatigue performance at room temperature, ensuring the durability and safety of tires under normal use conditions.
[0003] It is worth noting that with the widespread application of silica formulation technology in the tire industry, the limitations of traditional carbon black systems are becoming increasingly apparent. Due to its significant advantages in reducing tire rolling resistance and improving wet grip performance, silica has become a major component of high-end products such as green and energy-saving tires. However, in silica-based formulations, the proportion of carbon black added (phr) is usually controlled at a low level. This directly leads to insufficient blackness in rubber products and tires, resulting in a significant defect compared to the pure black appearance of traditional all-carbon-black tire formulations. This has become a technical challenge that urgently needs to be addressed in the high-end tire market. Summary of the Invention
[0004] Therefore, the present invention provides a rubber composition for improving tire color and a method for preparing the same, in order to solve the problem in the prior art where the finished rubber compound and tires have insufficient blackness due to the application of low carbon black content.
[0005] To achieve the above objectives, the present invention provides the following technical solution: According to a first aspect of the present invention, a rubber composition for improving tire color is provided, comprising the following components: natural rubber, butadiene rubber, silica, color black, processing oil, coupling agent, dispersant, activator, accelerator, vulcanizing agent and antioxidant.
[0006] Furthermore, chromatic carbon black is a type of carbon black with high blackness and high tinting strength, formed by increasing the absorption of visible light, improving tinting intensity, and reducing particle size.
[0007] Furthermore, the processed oil is an environmentally friendly aromatic oil.
[0008] Furthermore, the antioxidant is N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine.
[0009] Furthermore, the activator is zinc oxide.
[0010] Furthermore, the vulcanizing agent is sulfur.
[0011] Further, by weight, it contains the following components: 50-65 phr of natural rubber, 35-50 phr of butadiene rubber, 80-100 phr of silica, 5-10 phr of color carbon black, 10.25-15.25 phr of environmentally friendly aromatic oil, 7-10 phr of coupling agent, 3.3-6.5 phr of dispersant, 3.5-5.5 phr of activator ZnO, 3.0-5.5 phr of accelerator, 2.0-2.5 phr of sulfur, and 2.5-3.5 phr of antioxidant 6PPD.
[0012] According to a second aspect of the present invention, a method for preparing a rubber composition for improving tire color is provided, comprising the following steps: (1) Add natural rubber and butadiene rubber to the internal mixer and mix for 30 seconds; raise and lower the top plug, add silica, color black, coupling agent and dispersant, and mix for 1 minute; raise and lower the top plug, and when the temperature rises to 115°C, add environmentally friendly aromatic oil, activator ZnO and antioxidant 6PPD, and continue mixing; when the temperature rises to 150~160°C, discharge the rubber to obtain a first-stage compound; (2) Raise the top bolt, add a section of mixed rubber, accelerator and sulfur to the internal mixer, mix for 30~60s; when the temperature rises to 105℃, discharge the rubber to obtain the final rubber.
[0013] Furthermore, the internal mixer described in step (1) has a rotation speed of 30~50 r / min and a pressure of 15~18 MPa.
[0014] Furthermore, the internal mixer described in step (2) has a rotation speed of 30~40 r / min and a pressure of 14~17 MPa.
[0015] The present invention has the following advantages: This invention provides a rubber composition for improving tire color. By employing chromatic carbon black with high visible light absorption, strong coloring ability, and small particle size, and optimizing the silica formulation system, it effectively solves the problem of insufficient tire coloring caused by low carbon black content in traditional silica formulations, significantly improving the blackness and coloring performance of the rubber. This formulation, by balancing the synergistic effects of silica and carbon black, improves tire color by 7% to 15% while ensuring the reinforcing performance of the rubber. This not only effectively compensates for the visual defects of silica-based tires but also fully retains their advantages of low rolling resistance and high wet grip performance, significantly enhancing the appearance quality and market competitiveness of the finished tire. Detailed Implementation
[0016] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0017] The usage process of this invention embodiment is as follows: Example 1
[0018] A rubber composition for improving tire color comprises, by weight, the following components: 50 phr of natural rubber, 35 phr of butadiene rubber, 80 phr of silica, 5 phr of color black, 10.25 phr of environmentally friendly aromatic oil, 7 phr of coupling agent, 3.3 phr of dispersant, 3.5 phr of activator ZnO, 3.0 phr of accelerator, 2.0 phr of sulfur, and 2.5 phr of antioxidant 6 PPD.
[0019] The preparation method of the rubber composition is as follows: (1) Add natural rubber and butadiene rubber to the internal mixer and mix for 30 seconds; raise and lower the top plug, add silica, color black, coupling agent and dispersant, and mix for 1 minute; raise and lower the top plug, and when the temperature rises to 115°C, add environmentally friendly aromatic oil, activator ZnO and antioxidant 6PPD, and continue mixing; when the temperature rises to 155°C, discharge the rubber to obtain a first-stage compound; (2) Raise the top bolt, add a section of mixed rubber, accelerator and sulfur to the internal mixer, mix for 45s; when the temperature rises to 105℃, discharge the rubber to obtain the final rubber.
[0020] Example 2
[0021] The difference between Example 2 and Example 1 lies in the rubber composition, which, by weight, contains the following components: 57.5 phr of natural rubber, 42.5 phr of butadiene rubber, 90 phr of silica, 7.5 phr of chroma black, 12.75 phr of environmentally friendly aromatic oil, 8.5 phr of coupling agent, 4.9 phr of dispersant, 4.5 phr of activator ZnO, 4.3 phr of accelerator, 2.3 phr of sulfur, and 3 phr of antioxidant 6 PPD. The specific preparation method is the same as in Example 1.
[0022] Example 3
[0023] The difference between Example 3 and Example 1 lies in the rubber composition, which, by weight, contains the following components: 65 phr of natural rubber, 50 phr of butadiene rubber, 100 phr of silica, 10 phr of chroma black, 15.25 phr of environmentally friendly aromatic oil, 10 phr of coupling agent, 6.5 phr of dispersant, 5.5 phr of activator ZnO, 5.5 phr of accelerator, 2.5 phr of sulfur, and 3.5 phr of antioxidant 6 PPD. The specific preparation method is the same as in Example 1.
[0024] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the chroma black is replaced with carbon black; the rubber composition, by weight, contains the following components: 50 phr of natural rubber, 35 phr of butadiene rubber, 80 phr of silica, 5 phr of carbon black, 9.25 phr of environmentally friendly aromatic oil, 7 phr of coupling agent, 3.3 phr of dispersant, 3.5 phr of activator ZnO, 3.0 phr of accelerator, 2.0 phr of sulfur, and 2.5 phr of antioxidant 6 PPD. The specific preparation method is the same as in Example 1.
[0025] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that the chroma black is replaced with carbon black; the rubber composition, by weight, contains the following components: natural rubber 57.5 phr, butadiene rubber 42.5 phr, silica 90 phr, carbon black 5 phr, environmentally friendly aromatic oil 10.75 phr, coupling agent 8.5 phr, dispersant 4.9 phr, activator ZnO 4.5 phr, accelerator 4.3 phr, sulfur 2.3 phr and antioxidant 6 PPD 3 phr, and the specific preparation method is the same as in Example 1.
[0026] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that the chroma black is replaced with carbon black; the rubber composition, by weight, contains the following components: 65 phr of natural rubber, 50 phr of butadiene rubber, 100 phr of silica, 5 phr of carbon black, 12.25 phr of environmentally friendly aromatic oil, 10 phr of coupling agent, 6.5 phr of dispersant, 5.5 phr of activator ZnO, 5.5 phr of accelerator, 2.5 phr of sulfur and 3.5 phr of antioxidant 6 PPD, and the specific preparation method is the same as in Example 1.
[0027] The final rubbers prepared in Examples 1-3 and Comparative Examples 1-3 were placed back into the internal mixer and subjected to open mixing at 100°C for 5 minutes to prepare open mixing sheets with a thickness of 3 mm for later use.
[0028] In rubber compounding processes, specific surface area, color strength, specific gravity, oil absorption value, and iodine absorption value are important parameters for evaluating the physicochemical properties of fillers (carbon black and silica). This invention conducted the above-mentioned performance tests on the open mill sheets prepared in Examples 1-3 and Comparative Examples 1-3, and the results are shown in Table 1 below: Table 1
[0029] As can be seen from the parameters in Table 1 above, the open-mix rubber prepared in Examples 1-3 is superior to that of Comparative Examples 1-3 in terms of specific surface area, tinting strength, specific gravity, oil absorption value, and iodine absorption value. Specifically, the specific surface area is increased, thereby enhancing the interfacial interaction between carbon black and rubber; the tinting strength is increased, better improving the blackness of rubber products; and the oil absorption value and iodine absorption value are improved, optimizing the dispersibility and flowability of the filler. These characteristics indicate that the present invention effectively improves the reinforcing and coloring properties of fillers by modifying carbon black and optimizing the formulation of the silica system.
[0030] In rubber compounding, the LAD (Lubricant Analysis and Dispersion Test) is an important method for evaluating the uniformity of filler (carbon black and silica) dispersion in rubber compounds. This invention conducted LAD tests on the open mill sheets prepared in Examples 1-3 and Comparative Examples 1-3, and the results are shown in Table 2 below: Table 2
[0031] As can be seen from the parameters in Table 2, the open-mix rubber prepared using the formulation system of the present invention (Examples 1-3) has an effective improvement in tire color by 7% to 15% compared with the existing formulation system (Comparative Examples 1-3).
[0032] The open mill sheets prepared using Examples 1-3 and Comparative Examples 1-3 of this invention were subjected to conventional performance analysis, and the results are shown in Table 3 below: Table 3
[0033] As can be seen from the parameters in Table 3 above, there is no significant difference in conventional performance parameters between the open-mix rubber prepared in Examples 1-3 and Comparative Examples 1-3, and the performance of each indicator is quite similar.
[0034] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.
Claims
1. A rubber composition for improving the color tone of a tire, characterized by, The composition comprises the following components: natural rubber, cis-butadiene rubber, white carbon black, color carbon black, processing oil, coupling agent, dispersant, activator, accelerator, vulcanizing agent and antioxidant.
2. The rubber composition for improving the color tone of a tire according to claim 1, wherein The color carbon black is high blackness and high coloring capacity carbon black formed by increasing absorption of visible light, improving coloring intensity and reducing particle size.
3. The rubber composition for improving the color tone of a tire according to Claim 1, wherein The processing oil is environmentally friendly aromatic oil.
4. The rubber composition for improving the color tone of a tire according to Claim 1, wherein The antioxidant is N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine.
5. The rubber composition for improving the color tone of a tire according to Claim 1, wherein The activator is zinc oxide.
6. The rubber composition for improving the color tone of a tire according to claim 1, wherein The vulcanizing agent is sulfur.
7. The rubber composition for improving the color tone of a tire according to claim 1, wherein The composition comprises the following components by weight: natural rubber 50~65 phr, cis-butadiene rubber 35~50 phr, white carbon black 80~100 phr, color carbon black 5~10 phr, processing oil 10.25~15.25 phr, coupling agent 7~10 phr, dispersant 3.3~6.5 phr, activator 3.5~5.5 phr, accelerator 3.0~5.5 phr, vulcanizing agent 2.0~2.5 phr and antioxidant 2.5~3.5 phr.
8. A process for the preparation of a rubber composition for improving the color of a tire, for the preparation of a rubber composition for improving the color of a tire according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: (1) adding natural rubber and cis-butadiene rubber in an internal mixer, mixing for 30 s; lifting the upper plunger, adding white carbon black, color carbon black, coupling agent and dispersant, mixing for 1 min; lifting the upper plunger, adding processing oil, activator and antioxidant when the temperature rises to 115℃, continuing mixing; when the temperature rises to 150~160℃, discharging glue to obtain a first-stage mixing rubber; (2) lifting the upper plunger, adding the first-stage mixing rubber, accelerator and vulcanizing agent in the internal mixer, mixing for 30~60 s; discharging glue when the temperature rises to 105℃ to obtain a final mixing rubber.
9. The method of producing a rubber composition for improving the color tone of a tire according to claim 8, wherein The rotating speed of the internal mixer in step (1) is 30~50 r / min, and the pressure is 15~18 MPa.
10. The method of producing a rubber composition for improving the color tone of a tire according to Claim 8, characterized in that, The rotating speed of the internal mixer in step (2) is 30~40 r / min, and the pressure is 14~17 MPa.