Sidewall rubber composition, sidewall rubber and tire

Abstract

The present application relates to the technical field of composite materials, in particular to a sidewall rubber composition, a sidewall rubber and a tire. The sidewall rubber provided by the present application contains an environmentally friendly bio-based itaconate rubber, which is used to replace natural rubber or butadiene rubber in the traditional sidewall formula in equal amount, thereby reducing the dependence on petrochemical raw materials, being conducive to energy saving and carbon reduction, and the sidewall rubber composite obtained at the same time has excellent physical and mechanical properties, in particular has outstanding fatigue resistance and aging resistance, and has low heat generation and low rolling resistance, and other basic mechanical properties also meet the requirements. In addition, the processing technology of the sidewall rubber is simple, and the requirement for equipment is low. Experiments show that the sidewall rubber with high fatigue resistance, low compression heat generation and low rolling resistance is successfully prepared, wherein the sidewall rubber prepared by using aromatic oil and petroleum resin as plasticizer has a flex fatigue resistance of more than 5 million times, and the compression heat generation can be reduced to below 10 DEG C.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, specifically to sidewall rubber compositions, sidewall rubber, and tires. Background Technology

[0002] The main function of the sidewall is to protect the tire body. Its rubber compound must not only have excellent fatigue resistance and aging resistance, but also low rolling resistance and heat generation, as well as high tensile strength and high elongation.

[0003] In the existing technology, the base rubber of tire sidewall is mostly a combination of natural rubber and butadiene rubber. The main problem with this combination is that the performance varies greatly at different operating temperatures. For example, butadiene rubber is prone to crystallization at low temperatures, which reduces the physical properties of the sidewall rubber. This leads to cracks in the tire sidewall due to repeated bending and deformation, eventually causing tire fatigue failure and affecting the tire's service life.

[0004] On the other hand, the main raw materials for synthetic rubber used in the tire industry, such as styrene, isoprene, and butadiene, are all derived from non-renewable petrochemical resources. As a major consumer of petrochemical resources, the rubber industry generates large amounts of wastewater and waste gas. Meanwhile, the development of biomass energy and bio-based chemicals is gaining increasing attention worldwide, given their large reserves and carbon neutrality. Developing bio-based synthetic elastomers based on bio-based chemicals is of significant importance for sustainable development.

[0005] To address this, Chinese patent document CN104945817A discloses a method for preparing itaconic acid ester / butadiene copolymer bioengineering rubber. It introduces a bio-based itaconic acid ester rubber, whose raw materials do not rely on petrochemical resources but are mainly prepared from renewable biological resources. It exhibits good environmental stability and processability, and is a rubber product with excellent mechanical properties and dynamic viscoelasticity, suitable for high-performance green tire materials. It even has the potential to gradually replace traditional petroleum-based rubber, making it a novel green rubber material. Although this rubber has certain advantages in strength and tensile strength, it cannot meet the requirements for fatigue resistance, low compression heat generation, and low rolling resistance of tire-specific rubbers when used as a sidewall compound. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a sidewall rubber composition, a sidewall rubber and a tire, wherein the sidewall rubber composition provided by the present invention can be used to prepare a sidewall rubber with fatigue resistance, low compression heat generation and low rolling resistance.

[0007] This invention provides a sidewall rubber composition comprising, by weight, the following components:

[0008] Raw rubber: 100 parts; the raw rubber is composed of itaconic acid ester rubber, natural rubber and butadiene rubber in a mass ratio of (40-95):(10-20):(10-20);

[0009] Plasticizer: 5-10 parts.

[0010] The sidewall rubber composition of the present invention comprises 100 parts of raw rubber; the raw rubber is composed of itaconic acid ester rubber, natural rubber, and butadiene rubber in a mass ratio of (40-95):(10-20):(10-20). Based on 100 parts of raw rubber, the itaconic acid ester rubber is preferably 60 parts or more, more preferably 80 parts or more, and even more preferably 90 parts. If the content of the itaconic acid ester rubber component is less than 40 parts, the flexural fatigue resistance decreases significantly; if the content of this component is greater than 95 parts, the mechanical strength decreases. In some embodiments of the present invention, the mass ratio of the itaconic acid ester rubber, natural rubber, and butadiene rubber is preferably (60-95):20:20, more preferably (80-95):15:15, and even more preferably 90:10:10. In some embodiments of the present invention, the raw rubber is composed of itaconic acid ester rubber, natural rubber, and butadiene rubber in a mass ratio of (60-80):(10-20):(10-20). In some embodiments of the present invention, the itaconic acid ester rubber has a number-average molecular weight of 220,000 to 320,000 and a weight-average molecular weight of 650,000 to 900,000. In one embodiment, the itaconic acid ester rubber has a number-average molecular weight of 300,000 and a weight-average molecular weight of 870,000. In some embodiments of the present invention, the natural rubber has a weight-average molecular weight of 400,000 to 600,000. In some embodiments of the present invention, the butadiene rubber has a weight-average molecular weight of 270,000 to 350,000.

[0011] The sidewall rubber composition of the present invention comprises 5-10 parts of plasticizer, preferably 5-8 parts of plasticizer; the plasticizer is selected from petroleum-based plasticizers, kerosene plasticizers, pine tar-based plasticizers, fatty oil-based plasticizers, or synthetic plasticizers. The plasticizer of the present invention is preferably selected from one or more of petroleum resins, aromatic oils, paraffin oils, coal tar, coumarone, rosin, ointments, glycerin, castor oil, soybean oil, phthalates, fatty diacids, and phosphate esters. In some embodiments of the present invention, the plasticizer is selected from one or two of C5 petroleum resins or environmentally friendly aromatic oil Vivatec 500. The plasticizer of the present invention, when used in combination with the above-mentioned raw rubber, improves the fatigue resistance of the obtained sidewall rubber, reduces its compression heat generation and rolling resistance, and some types of plasticizers, such as petroleum resins or aromatic oils, when used in combination with the above-mentioned raw rubber, achieve significantly better fatigue resistance, lower compression heat generation, and lower rolling resistance.

[0012] In the raw rubber of the present invention, the itaconic acid ester rubber is obtained by copolymerization of raw materials including itaconic acid ester and conjugated diene; the itaconic acid ester is selected from one or two of dimethyl itaconic acid ester, diethyl itaconic acid ester, di-n-propyl itaconic acid ester, di-n-butyl itaconic acid ester, diisopropyl itaconic acid ester, diisobutyl itaconic acid ester, di-n-pentyl itaconic acid ester and diisopentyl itaconic acid ester; the conjugated diene is selected from one of isoprene or butadiene.

[0013] In the raw rubber of this invention, the itaconic acid ester rubber can be a binary copolymer obtained by copolymerizing itaconic acid ester and conjugated diene raw materials, or a ternary copolymer or quaternary copolymer obtained by copolymerizing itaconic acid ester and conjugated diene raw materials with the addition of one or two third components. In some embodiments of this invention, the itaconic acid ester rubber is obtained by copolymerizing raw materials including itaconic acid ester, conjugated diene and a third component; the third component is selected from one or two of glycidyl methacrylate, styrene, vinyl chloride acetate, acrylamide, cyclopentadiene, ethylenediene norbornene, methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, hydroxyethyl methacrylate and 2-hydroxyethyl acrylate.

[0014] The sidewall rubber composition provided by the present invention further includes the following components:

[0015] Reinforcing filler: 30-60 parts;

[0016] Activator: 1.5–5 parts;

[0017] Anti-aging agent: 3-9 parts;

[0018] Accelerator: 1-3 parts;

[0019] Vulcanizing agent: 1-3 parts.

[0020] Specifically, the sidewall rubber composition of the present invention further includes 30-60 parts of a reinforcing filler, wherein the reinforcing filler is selected from one or more of carbon black, calcium carbonate, calcium sulfate, dolomite powder, kaolin, clay, montmorillonite, clay, barium montmorillonite sulfate, talc, magnesium carbonate, magnesium silicate, and graphene. In some embodiments of the present invention, the reinforcing filler is selected from carbon black. In one embodiment, the reinforcing filler is selected from 40 parts of carbon black N550.

[0021] The sidewall adhesive composition of the present invention further includes 1.5 to 5 parts of an activator, preferably 4 parts of an activator. The activator of the present invention is selected from one or more of zinc oxide, stearic acid, polyethylene glycol, and magnesium oxide, wherein the amount of zinc oxide is 1.5 to 5 parts, the amount of stearic acid is 1.5 to 3 parts, the amount of polyethylene glycol is 2 to 5 parts, and the amount of magnesium oxide is 3 to 5 parts. In one embodiment, the activator is selected from 2 parts of zinc oxide and 2 parts of stearic acid.

[0022] The sidewall rubber composition of the present invention further includes 3 to 9 parts of antioxidant, preferably 3 to 6 parts of antioxidant, and more preferably 5 parts of antioxidant. The antioxidant of the present invention is selected from one or more of amine antioxidants, ketone amine antioxidants, phenolic antioxidants and heterocyclic antioxidants, and the amount of each antioxidant is 1 to 4 parts. Amine antioxidants are suitable for protecting rubber from aging factors such as light, heat, and oxygen. Examples include antioxidant 4010 (also known as antioxidant CPPD, N-phenyl-N'-cyclohexyl-p-phenylenediamine), antioxidant 4020 (also known as antioxidant DMPPD, N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine), and antioxidant 4010NA (also known as antioxidant IPPD, N-phenyl-N'-isopropyl-p-phenylenediamine). Ketoamine antioxidants are very effective for heat and oxygen protection, such as antioxidant RD (a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline). In some embodiments of the present invention, the sidewall rubber composition preferably includes 3 to 6 parts of amine antioxidants, specifically preferably 2 to 4 parts of antioxidant 4020 and 1 to 2 parts of antioxidant RD. In one embodiment, the sidewall rubber composition of the present invention comprises 5 parts of an amine antioxidant, specifically 3.5 parts of antioxidant 4020 and 1.5 parts of antioxidant RD.

[0023] The sidewall adhesive composition of the present invention further includes 1 to 3 parts of an accelerator, preferably 0.5 to 2 parts of an accelerator, and more preferably 1 part of an accelerator. The accelerator of the present invention is selected from one or more of dithiocarbamates, amine accelerators, sulfenamide accelerators, thiazole accelerators, and thiuram accelerators, preferably sulfenamide accelerators, and the amount of each accelerator is 0.5 to 5 parts. In some embodiments of the present invention, the sidewall adhesive composition of the present invention preferably includes 0.5 to 2 parts of a sulfenamide accelerator. In one embodiment, the sidewall adhesive composition of the present invention includes 1 part of a sulfenamide accelerator, wherein the sulfenamide accelerator is selected from accelerator NS.

[0024] The sidewall rubber composition of the present invention further includes 1 to 3 parts of a vulcanizing agent, preferably 1.5 parts of a vulcanizing agent. The vulcanizing agent of the present invention is selected from sulfur. In one embodiment, the sidewall rubber composition of the present invention includes 1.5 parts of sulfur.

[0025] In one embodiment of the present invention, the sidewall rubber composition of the present invention comprises, by weight, the following components: itaconic acid ester rubber: 60 parts; natural rubber: 20 parts; butadiene rubber: 20 parts; C5 petroleum resin: 1.5 parts; Vivatec 500 aromatic oil: 1.5 parts; carbon black N550: 40 parts; zinc oxide: 2 parts; stearic acid: 2 parts; antioxidant 4020: 3.5 parts; antioxidant RD: 1.5 parts; accelerator NS: 1 part; sulfur: 1.5 parts.

[0026] In another embodiment of the present invention, the sidewall rubber composition of the present invention comprises, by weight, the following components: itaconic acid ester rubber: 70 parts; natural rubber: 20 parts; butadiene rubber: 10 parts; C5 petroleum resin: 1.5 parts; Vivatec 500 aromatic oil: 1.5 parts; carbon black N550: 40 parts; zinc oxide: 2 parts; stearic acid: 2 parts; antioxidant 4020: 3.5 parts; antioxidant RD: 1.5 parts; accelerator NS: 1 part; sulfur: 1.5 parts.

[0027] In another embodiment of the present invention, the sidewall rubber composition of the present invention comprises, by weight, the following components: itaconic acid ester rubber: 70 parts; natural rubber: 10 parts; butadiene rubber: 20 parts; C5 petroleum resin: 1.5 parts; Vivatec 500 aromatic oil: 1.5 parts; carbon black N550: 40 parts; zinc oxide: 2 parts; stearic acid: 2 parts; antioxidant 4020: 3.5 parts; antioxidant RD: 1.5 parts; accelerator NS: 1 part; sulfur: 1.5 parts.

[0028] In another embodiment of the present invention, the sidewall rubber composition of the present invention comprises, by weight, the following components: itaconic acid ester rubber: 80 parts; natural rubber: 10 parts; butadiene rubber: 10 parts; C5 petroleum resin: 1.5 parts; Vivatec 500 aromatic oil: 1.5 parts; carbon black N550: 40 parts; zinc oxide: 2 parts; stearic acid: 2 parts; antioxidant 4020: 3.5 parts; antioxidant RD: 1.5 parts; accelerator NS: 1 part; sulfur: 1.5 parts.

[0029] This invention also provides a sidewall adhesive prepared from the above-mentioned sidewall adhesive composition. The sidewall adhesive prepared from the above-mentioned sidewall adhesive composition uses itaconic acid ester rubber, natural rubber, and butadiene rubber as raw rubber and plasticizers, which improves the fatigue resistance and reduces compression heat generation of the prepared sidewall adhesive. It has been found that when combined with petroleum resin or aromatic oil plasticizers, the prepared sidewall adhesive exhibits even more outstanding fatigue resistance and lower compression heat generation, with a flexural fatigue resistance exceeding 5 million cycles and compression heat generation reduced to below 10°C. This meets the application requirements for special sidewall adhesives and is a low-heat, long-life bio-based itaconic acid ester elastomer sidewall adhesive.

[0030] This invention also provides a method for preparing the above-mentioned sidewall rubber, comprising the following steps: mixing raw rubber, reinforcing filler, activator, antioxidant, and plasticizer for a first mixing process to obtain a first-stage masterbatch; mixing the first-stage masterbatch, vulcanizing agent, and accelerator for a second mixing process to obtain a second-stage final compound; and hot-pressing and vulcanizing the second-stage final compound to obtain the sidewall rubber. The raw rubber, reinforcing filler, activator, antioxidant, plasticizer, vulcanizing agent, and accelerator described in this invention are the same as those described above and will not be repeated.

[0031] This invention first involves mixing raw rubber, reinforcing filler, activator, antioxidant, and plasticizer for a first mixing process. Specifically, the plasticized raw rubber, reinforcing filler, activator, antioxidant, and plasticizer are first mixed and mixed at 140-170°C, then discharged to obtain a masterbatch. In one embodiment, the raw rubber is first plasticized in an internal mixer to obtain plasticized rubber. Then, reinforcing filler, activator, antioxidant, and plasticizer are added to the plasticized rubber and mixed for a first mixing process. When the temperature in the internal mixer reaches 140-170°C, the discharged rubber is obtained to obtain a masterbatch. The plasticizing time of the raw rubber in this invention is 1.5 minutes; the rotation speed of the internal mixer is 70 rpm.

[0032] In this invention, after obtaining a first-stage masterbatch, the first-stage masterbatch, vulcanizing agent, and accelerator are mixed and subjected to a second mixing process to obtain a second-stage final compound. Specifically, in this invention, the first-stage masterbatch, vulcanizing agent, and accelerator are mixed and subjected to a second mixing process at 90-110°C, and then the compound is discharged to obtain the second-stage final compound. In one embodiment, after obtaining a first-stage masterbatch, the first-stage masterbatch is cooled, and then the cooled first-stage masterbatch, vulcanizing agent, and accelerator are mixed and subjected to a second mixing process in an internal mixer at 90-110°C, and then the compound is discharged to obtain the second-stage final compound.

[0033] After obtaining the two-stage final compound, the present invention hot-presses and vulcanizes the two-stage final compound to obtain the sidewall rubber. Specifically, the present invention thins the two-stage final compound, rolls it out with a 2mm roller gap, places it in place, and vulcanizes it to obtain the sidewall rubber. In one embodiment, the present invention thins the two-stage final compound 6 times, rolls it out with a 2mm roller gap, places it in place, and obtains the sidewall rubber compound. The vulcanization characteristics of the sidewall rubber compound are then tested using a rotorless vulcanizing machine, and vulcanized using a flat vulcanizing machine to obtain the vulcanized rubber, which is the sidewall rubber of the present invention. The placing temperature in the present invention is 20-30℃, the placing time is 18-24 hours, and the vulcanization temperature is 150-180℃.

[0034] The present invention also provides a tire having a sidewall comprising the aforementioned sidewall rubber.

[0035] This invention provides a sidewall rubber composition, a sidewall rubber, and a tire. The sidewall rubber provided by this invention contains environmentally friendly bio-based itaconic acid ester rubber, which replaces natural rubber or butadiene rubber in traditional sidewall formulations in an equal amount with bio-based itaconic acid ester rubber prepared from biomass resources, reducing dependence on petrochemical raw materials and contributing to energy conservation and carbon reduction. Simultaneously, the resulting sidewall rubber composite material exhibits excellent physical and mechanical properties, particularly outstanding fatigue resistance and aging resistance, as well as low heat generation and rolling resistance, while other basic mechanical properties also meet requirements. Furthermore, the sidewall rubber processing technology is simple and requires minimal equipment. Experiments show that this invention successfully prepares a sidewall rubber with outstanding fatigue resistance, low compression heat generation, and low rolling resistance. The sidewall rubber prepared using aromatic oils and petroleum resins as plasticizers can withstand over 5 million flexural fatigue cycles, and the compression heat generation can be reduced to below 10°C. Attached Figure Description

[0036] Figure 1 The figures show the DMA test results of the embodiments and comparative examples of this application at different temperatures;

[0037] Figure 2 The figures show the DMA test results of the embodiments and comparative examples of this application at 60°C.

[0038] Figure 3 This is a schematic diagram showing the flexural fatigue results of 5 million+ cycles in Examples 1-4;

[0039] Figure 4 This is a schematic diagram of the flexural fatigue results for different flexion cycles in Example 5;

[0040] Figure 5 This is a schematic diagram showing the flexural fatigue results of different flexion cycles in Comparative Example 1.

[0041] Figure 6 This is a schematic diagram showing the flexural fatigue results for different flexion cycles in Comparative Example 2. Detailed Implementation

[0042] This invention discloses a sidewall rubber composition, a sidewall rubber, and a tire. Those skilled in the art can refer to this document and appropriately modify the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art will clearly be able to modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0043] The present invention will be further described below with reference to the embodiments:

[0044] In the following examples and comparative examples, itaconic acid ester rubber was prepared in-house, obtained by copolymerizing dibutyl itaconic acid and butadiene, with a number average molecular weight of 300,000 and a weight average molecular weight of 870,000; natural rubber was commercially available, grade CV60, with a weight average molecular weight of 400,000 to 600,000; cis-butadiene rubber was BR9000, with a weight average molecular weight of 270,000 to 350,000; other raw and auxiliary materials were all commercially available products.

[0045] Example 1

[0046] A low-heat-generating, long-life bio-based itaconic acid ester elastomer sidewall rubber contains the following components by weight: 60 parts itaconic acid ester rubber (PDBIB), 20 parts natural rubber (NR), 20 parts butadiene rubber (BR), 40 parts carbon black N550, 2 parts zinc oxide, 2 parts stearic acid, 3.5 parts antioxidant 4020, 1.5 parts antioxidant RD, 1.5 parts C5 petroleum resin, 1.5 parts Vivatec 500 aromatic oil, 1.5 parts sulfur, and 1 part accelerator NS.

[0047] The preparation method involves the following steps:

[0048] (1) Plasticize itaconic acid ester rubber, natural rubber and butadiene rubber in an internal mixer for 1.5 min at a speed of 70 rpm;

[0049] (2) Add carbon black N550, zinc oxide, stearic acid, antioxidant 4020, antioxidant RD, C5 petroleum resin and environmentally friendly aromatic oil vivatec500 in sequence and mix them. When the temperature in the internal mixer reaches 150℃, discharge the rubber to obtain a first-stage masterbatch.

[0050] (3) After the first stage of masterbatch from step (2) has cooled to a temperature of less than 70°C, the masterbatch, sulfur, and accelerator NS are put into the internal mixer and continue to be mixed. When the temperature in the internal mixer reaches 110°C, the rubber is discharged to obtain the second stage final rubber.

[0051] (4) The two-stage final compound from step (3) is passed through a two-roll mill 6 times, with a 2mm roller gap, and then left to stand for 18 hours at a temperature of 20-30℃ to obtain the tire sidewall compound.

[0052] (5) The compound obtained in step (4) is tested for vulcanization characteristics using a rotorless vulcanizer. A vulcanized rubber sample is obtained using a flat vulcanization mechanism. The obtained vulcanized rubber sample is the bio-based itaconic acid elastomer sidewall rubber. The vulcanization temperature is 150-180℃.

[0053] Example 2

[0054] A low-heat-generating, long-life bio-based itaconic acid ester elastomer sidewall rubber contains the following components by weight: 70 parts itaconic acid ester rubber (PDBIB), 20 parts natural rubber (NR), 10 parts butadiene rubber (BR), 40 parts carbon black N550, 2 parts zinc oxide, 2 parts stearic acid, 3.5 parts antioxidant 4020, 1.5 parts antioxidant RD, 1.5 parts C5 petroleum resin, 1.5 parts vivatec 500 aromatic oil, 1.5 parts sulfur, and 1 part accelerator NS. The sidewall rubber composite material was prepared according to the same preparation method as in Example 1.

[0055] Example 3

[0056] A low-heat-generating, long-life bio-based itaconic acid ester elastomer sidewall rubber contains the following components by weight: 70 parts itaconic acid ester rubber (PDBIB), 10 parts natural rubber (NR), 20 parts butadiene rubber (BR), 40 parts carbon black N550, 2 parts zinc oxide, 2 parts stearic acid, 3.5 parts antioxidant 4020, 1.5 parts antioxidant RD, 1.5 parts C5 petroleum resin, 1.5 parts vivatec 500 aromatic oil, 1.5 parts sulfur, and 1 part accelerator NS. The sidewall rubber composite material was prepared according to the same preparation method as in Example 1.

[0057] Example 4

[0058] A low-heat-generating, long-life bio-based itaconic acid ester elastomer sidewall rubber contains the following components by weight: 80 parts itaconic acid ester rubber (PDBIB), 10 parts natural rubber (NR), 10 parts butadiene rubber (BR), 40 parts carbon black N550, 2 parts zinc oxide, 2 parts stearic acid, 3.5 parts antioxidant 4020, 1.5 parts antioxidant RD, 1.5 parts C5 petroleum resin, 1.5 parts vivatec 500 aromatic oil, 1.5 parts sulfur, and 1 part accelerator NS. The sidewall rubber composite material was prepared according to the same preparation method as in Example 1.

[0059] Example 5

[0060] A low-heat-generating, long-life bio-based itaconic acid ester elastomer sidewall rubber contains the following components by weight: 80 parts itaconic acid ester rubber (PDBIB), 10 parts natural rubber (NR), 10 parts butadiene rubber (BR), 40 parts carbon black N550, 2 parts zinc oxide, 2 parts stearic acid, 3.5 parts antioxidant 4020, 1.5 parts antioxidant RD, 1.5 parts microcrystalline wax Antilux 111, 1.5 parts naphthenic oil 4006, 1.5 parts sulfur, and 1 part accelerator NS. The sidewall rubber composite material was prepared according to the same preparation method as in Example 1.

[0061] Comparative Example 1

[0062] A high-fatigue-resistant bio-based tire sidewall rubber composite material contains the following raw materials by weight: 50 parts natural rubber (NR), 50 parts butadiene rubber (BR), 40 parts carbon black N550, 2 parts zinc oxide, 2 parts stearic acid, 3.5 parts antioxidant 4020, 1.5 parts antioxidant RD, 1.5 parts C5 petroleum resin, 1.5 parts Vivacatec500 aromatic oil, 1.5 parts sulfur, and 1 part accelerator NS. The tire sidewall rubber composite material was prepared according to the same preparation method as in Example 1.

[0063] Comparative Example 2

[0064] A high-fatigue-resistant bio-based tire sidewall rubber composite material contains the following raw materials by weight: 30 parts itaconic acid ester rubber (PDBIB), 40 parts natural rubber (NR), 30 parts butadiene rubber (BR), 40 parts carbon black N550, 2 parts zinc oxide, 2 parts stearic acid, 3.5 parts antioxidant 4020, 1.5 parts antioxidant RD, 1.5 parts C5 petroleum resin, 1.5 parts vivatec500 aromatic oil, 1.5 parts sulfur, and 1 part accelerator NS. The sidewall rubber composite material was prepared according to the same preparation method as in Example 1.

[0065] The performance comparison of the sidewall rubber composite materials prepared in the embodiments of the present invention is shown in Table 1 and Table 2. Table 1 is a table of test results of the physical and mechanical properties of the sidewall rubber composite materials prepared in the embodiments of the present invention and the comparative examples.

[0066] Table 1

[0067]

[0068]

[0069] As shown in Table 1, the sidewall rubber composite material prepared in the embodiments of the present invention exhibits excellent mechanical properties, particularly in terms of fatigue resistance. Furthermore, the composite material demonstrates excellent resistance to heat and oxygen aging. This invention partially replaces natural rubber or butadiene rubber in traditional sidewall formulations with bio-based itaconic acid ester rubber prepared from renewable biomass resources, meeting the requirements of green and low-carbon development and aligning with the current trend of sustainable green development.

[0070] Table 2 shows the dynamic mechanical properties (DMA) test results of the sidewall rubber composite materials prepared according to the present invention and the comparative example.

[0071] Table 2

[0072] project Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Example 5 tanδ@60℃ 0.104 0.089 0.088 0.078 0.076 0.071 0.090 tanδ@0℃ 0.150 0.389 0.373 0.345 0.323 0.302 0.321

[0073] Note: The DMA test conditions are: frequency 10Hz, temperature range -80~80℃, heating rate 3℃ / min, dynamic strain 0.25%, and static strain 2.5%.

[0074] In the tire industry, the tanδ value at 60°C is typically used to represent the quality of rolling resistance. As shown in Table 2, in all embodiments of the present invention, the tanδ at 60°C is significantly lower than that in the comparative example, indicating that applying the present invention to the tire sidewall can effectively reduce the hysteresis loss of the tire sidewall, thereby reducing heat generation on the tire sidewall and the rolling resistance of the tire.

[0075] in addition, Figure 1 The graph shows the DMA test results of the embodiments and comparative examples of this application at different temperatures. Figure 2 The graph shows the DMA test results of the embodiments and comparative examples of this application at 60°C. Figure 1 and Figure 2 It can be seen that, compared with Comparative Examples 1 and 2 (where the amount of itaconic acid rubber was 0 and 30 phr respectively), Examples 1-5 showed a smaller tanδ at 60°C, thus exhibiting the lowest rolling resistance. Furthermore, the higher the proportion of itaconic acid rubber in the blend, the smaller the tanδ at 60°C, indicating better rolling resistance performance. In addition, the tanδ at 60°C in Examples 1-4 was also significantly smaller than that in Example 5.

[0076] Figure 3 This is a schematic diagram showing the flexural fatigue results of 5 million+ cycles in Examples 1-4. Figure 4 This is a schematic diagram of the flexural fatigue results at different flexion cycles in Example 5. Figure 5 This is a schematic diagram showing the flexural fatigue results at different flexion cycles in Comparative Example 1. Figure 6 This is a schematic diagram showing the flexure fatigue results at different flexion cycles in Comparative Example 2; (from...) Figures 3-6It can be seen that, compared with Comparative Example 1 (where the amount of itaconic acid rubber was 0), the samples in Examples 1-4 did not show pinholes (i.e., grade 1 cracking) even after more than 5 million flexures; while the sample in Comparative Example 1 showed several pinholes after more than 1.6 million flexures, and the pinholes enlarged significantly after 1.7 million flexures; when the number of flexures increased to 3.5 million flexures, the length of the largest crack exceeded 3 mm, i.e., grade 6 cracking; and the sample completely fractured after 4.75 million flexures. Compared with Comparative Example 2, which used 30 parts of itaconic acid rubber in its formulation, the sample showed pinholes after 2.1 million flexures, and grade 6 cracking appeared after 4 million flexures. The above results indicate that replacing part of the natural rubber or butadiene rubber with itaconic acid rubber can significantly improve the flexural fatigue resistance of the samples. In addition, the formulation of Example 5 used the plasticizer Antilux111 microcrystalline wax and naphthenic oil 4006. The sample produced pinholes after 3.6 million flexures. When the number of flexures was 4.5 million, grade 6 cracks appeared. The flexural fatigue resistance was improved compared with Comparative Examples 1 and 2, but worse than Example 4.

[0077] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A sidewall rubber composition, characterized in that, Based on parts by weight, it includes the following components: Raw rubber: 100 parts; the raw rubber is composed of itaconic acid ester rubber, natural rubber and butadiene rubber in a mass ratio of (40~95):(10~20):(10~20); Plasticizer: 5-10 parts; The plasticizer is a petroleum resin and an aromatic oil.

2. The sidewall rubber composition according to claim 1, characterized in that, The raw rubber is composed of itaconic acid ester rubber, natural rubber and butadiene rubber in a mass ratio of (60~80):(10~20):(10~20).

3. The sidewall rubber composition according to claim 1, characterized in that, The itaconic acid ester rubber is obtained by copolymerization of raw materials including itaconic acid ester and conjugated diene; The itaconic acid ester is selected from one or two of dimethyl itaconic acid, diethyl itaconic acid, dipropyl itaconic acid, dibutyl itaconic acid, diisopropyl itaconic acid, diisobutyl itaconic acid, dipentyl itaconic acid, and diisopentyl itaconic acid. The conjugated diene is selected from either isoprene or butadiene.

4. The sidewall rubber composition according to claim 3, characterized in that, The itaconic acid ester rubber is obtained by copolymerization of raw materials including itaconic acid ester, conjugated diene and a third component; The third component is selected from one or two of glycidyl methacrylate, styrene, vinyl chloroacetate, acrylamide, cyclopentadiene, ethylenediene norbornene, methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, hydroxyethyl methacrylate, and 2-hydroxyethyl acrylate.

5. The sidewall rubber composition according to claim 1, characterized in that, It also includes the following components: Reinforcing filler: 30-60 parts; Activator: 1.5~5 parts; Anti-aging agent: 3-9 parts; Accelerator: 1-3 parts; Vulcanizing agent: 1-3 parts.

6. The sidewall rubber composition according to claim 5, characterized in that, The reinforcing filler is selected from one or more of carbon black, calcium carbonate, calcium sulfate, dolomite powder, clay, montmorillonite, clay, barium montmorillonite sulfate, talc, magnesium carbonate, magnesium silicate, and graphene. The activator is selected from one or more of zinc oxide, stearic acid, polyethylene glycol, and magnesium oxide; The antioxidant is selected from one or more of amine antioxidants, phenolic antioxidants, and heterocyclic antioxidants; The accelerator is selected from one or more of dithiocarbamates, amine accelerators, sulfenamide accelerators, thiazole accelerators, and thiuram accelerators; The vulcanizing agent is selected from sulfur.

7. The sidewall rubber composition according to claim 6, characterized in that, The antioxidant is selected from one or more of ketone amine antioxidants, phenolic antioxidants, and heterocyclic antioxidants.

8. The sidewall rubber composition according to claim 5, characterized in that, Includes the following components: Itaconic acid ester rubber: 60 parts; natural rubber: 20 parts; butadiene rubber: 20 parts; C5 petroleum resin: 1.5 parts; Vivatec 500 aromatic oil: 1.5 parts; carbon black N550: 40 parts; Zinc oxide: 2 parts; stearic acid: 2 parts; antioxidant 4020: 3.5 parts; antioxidant RD: 1.5 parts; accelerator NS: 1 part; sulfur: 1.5 parts; Alternatively, it may include the following components: Itaconic acid ester rubber: 70 parts; natural rubber: 20 parts; butadiene rubber: 10 parts; C5 petroleum resin: 1.5 parts; Vivatec 500 aromatic oil: 1.5 parts; carbon black N550: 40 parts; zinc oxide: 2 parts; stearic acid: 2 parts; antioxidant 4020: 3.5 parts; antioxidant RD: 1.5 parts; accelerator NS: 1 part; sulfur: 1.5 parts; Alternatively, it may include the following components: Itaconic acid ester rubber: 70 parts; natural rubber: 10 parts; butadiene rubber: 20 parts; C5 petroleum resin: 1.5 parts; Vivatec 500 aromatic oil: 1.5 parts; carbon black N550: 40 parts; Zinc oxide: 2 parts; stearic acid: 2 parts; antioxidant 4020: 3.5 parts; antioxidant RD: 1.5 parts; accelerator NS: 1 part; sulfur: 1.5 parts; Alternatively, it may include the following components: Itaconic acid ester rubber: 80 parts; natural rubber: 10 parts; butadiene rubber: 10 parts; C5 petroleum resin: 1.5 parts; Vivatec 500 aromatic oil: 1.5 parts; carbon black N550: 40 parts; Zinc oxide: 2 parts; stearic acid: 2 parts; antioxidant 4020: 3.5 parts; antioxidant RD: 1.5 parts; accelerator NS: 1 part; sulfur: 1.5 parts.

9. A sidewall adhesive prepared from any one of the sidewall adhesive compositions according to claims 1 to 8.

10. A tire, characterized in that, It has a sidewall comprising the sidewall rubber of claim 9.

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