Rubber composition and preparation method therefor, and OTR engineering tire using same

Abstract

The present application belongs to the technical field of rubbers, and particularly relates to a rubber composition and a preparation method therefor, and an OTR engineering tire using same. The rubber composition disclosed in the present application comprises (in parts by mass) 100 parts of a diene rubber, 0-1.5 parts of a tetrazine compound, 0.2-1.5 parts of a pyrazolone compound, 0-30 parts of a liquid rubber, 20-100 parts of a reinforcing filler, 0-5 parts of a silane coupling agent, 2-10 parts of a vulcanization activator, and a vulcanization accelerator, a vulcanizing agent, an antioxidant, a resin and a plasticizer. Moreover, the ratios of the tetrazine compound and the liquid rubber are not zero at the same time. The present application can significantly reduce the heat generated by the OTR engineering tire, and can also improve the damage resistance of the tire.

Description

A rubber composition and its preparation method, and an OTR engineering tire using the same.

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 2024115783864, filed on November 7, 2024, entitled "A rubber composition and a method for preparing the same, and an OTR engineering tire using the same", and Chinese Patent Application No. 2025106921376, filed on May 27, 2025, entitled "A rubber composition and a method for preparing the same, and an OTR engineering tire using the same", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of rubber technology, specifically relating to a rubber composition and its preparation method, and an OTR engineering tire using the same. Background Technology

[0004] During operation, heavy-duty engineering vehicles face harsh road conditions. Under high loads and cyclic deformation, the tire rubber is subjected to damaging environments such as heat and oxygen, fatigue, and cutting / tearing. Reducing tire heat generation and improving its resistance to cuts and tears are crucial for extending tire lifespan. Traditional methods, such as changing the type of rubber or increasing the amount of silica, often have limitations in terms of performance. Low-heat-generating rubber materials require low energy dissipation (hysteresis loss), while high cut and tear resistance under large deformation requires high energy dissipation. Therefore, low heat generation and high cut and tear resistance are contradictory. Reducing heat generation often degrades cut and tear resistance, and improving one property often results in the loss of others, making it difficult to improve the overall tire lifespan. In practical applications, styrene-butadiene rubber (SBR)-based rubber compositions are used to improve cut and tear resistance under harsh road conditions, but their high heat generation can affect service life. In less harsh road conditions, natural rubber-based compositions are used to reduce heat generation and improve service life, but their poor cut resistance also affects service life. Therefore, achieving both low heat generation and high cut and tear resistance simultaneously is currently quite difficult.

[0005] To address this technical need, patent publication numbers CN110392713B, CN108026332B, CN110382611B, CN110382612B, CN110382554B, and CN110461931B disclose rubber compositions and tires. By combining specific rubber components, tetrazine compounds represented by general formula (4) or their salts, and carbon black and carbon white, a rubber composition can be provided that not only imparts excellent low heat generation properties to the tire, but also excellent wear resistance. However, these published patents do not describe or provide example data regarding cut and tear resistance. In addition, by using the rubber composition of this invention to manufacture tires, not only can the rolling resistance and heat generation of the tire be reduced, but wear resistance can also be improved. Therefore, low fuel consumption tires for large automobiles can be provided. However, wear resistance refers to the wear resistance performance under small deformation under mild road conditions, which is not contradictory to the low heat generation under high dispersion of fillers in rubber. But it is contradictory to the rubber mechanism of cut resistance and tear resistance under large deformation under harsh road conditions. Therefore, the tires made of this rubber composition have weaker or even worse anti-damage performance such as cut resistance and tear resistance, and cannot meet the use requirements of OTR engineering tires under harsh road conditions.

[0006] Patent publication number CN112533991B discloses rubber compositions, rubber materials and their uses, and additives represented by general formulas (2) and (3) that can exhibit low heat generation, tear strength and durability; and rubber compositions with excellent low heat generation, tear strength and durability. In examples where the amount of natural rubber (NR) or polyisoprene rubber (IR) is 100 parts or more than 50 parts, pyrazolone compounds have good low heat generation, tear strength and durability; however, there are no examples showing that when the amount of synthetic rubber such as styrene-butadiene rubber (SBR) exceeds 50 parts, low heat generation and tear strength and durability are simultaneously improved. Since the reactivity of pyrazolone compounds with natural rubber is higher than that with synthetic rubber such as styrene-butadiene rubber, pyrazolone compounds can achieve good low heat generation and tear strength in rubber compositions with natural rubber as the main component (more than 50 parts), but cannot simultaneously achieve low heat generation and high tear strength in rubber compositions with styrene-butadiene rubber as the main component (more than 50 parts). Therefore, tires made from this styrene-butadiene rubber composition have weaker or even worse performance in terms of low heat generation, cut resistance, and tear resistance, and cannot meet the requirements of OTR engineering tires for use in harsh road conditions.

[0007] Therefore, how to provide a rubber composition that reduces heat generation while improving resistance to damage, and its preparation method, are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0008] In view of this, the first objective of this application is to address the problems existing in the prior art by providing a rubber composition that can be used to reduce heat generation and improve resistance to damage in OTR engineering tires.

[0009] To achieve the above objectives, this application adopts the following technical solution:

[0010] A rubber composition comprising the following raw materials in parts by weight: 100 parts diene rubber, 0-1.5 parts tetrazine compound, 0.2-1.5 parts pyrazolone compound, 0-30 parts liquid rubber, 20-100 parts reinforcing filler, 0-5 parts silane coupling agent, and 2-10 parts vulcanization activator, wherein the proportions of the tetrazine compound and the liquid rubber are not simultaneously zero; wherein,

[0011] The structure of the tetrazine compound is as follows:

[0012] Where X 1 X 2 This indicates a heterocyclic group that may have substituents, wherein the substituents are alkyl, aralkyl, aryl, or heterocyclic groups; the structure of the pyrazolone compound is as follows:

[0013] In this context, R1, R2, R3, and R4 each independently represent a hydrogen atom, alkyl, aralkyl, aryl, or heterocyclic group; R3 and R4 can be linked to form an alkylene group, and any two of R2, R3, and R4 can be linked together to form an alkylene group; R5, R7, and R8 each independently represent a hydrogen atom, alkyl, aralkyl, aryl, or heterocyclic group; R6 represents an alkyl, aralkyl, aryl, or heterocyclic group; and each of these groups can independently have one or more substituents.

[0014] The structure of the liquid rubber is as follows:

[0015] Where l, m, and n are any integers from 1 to 1000.

[0016] Preferably, the rubber composition comprises the following raw materials in parts by weight: 100 parts of diene rubber, 0.2-1.5 parts of tetrazine compound, 0.2-1.5 parts of pyrazolone compound, 0-30 parts of liquid rubber, 20-100 parts of reinforcing filler, 0-5 parts of silane coupling agent, and 2-10 parts of vulcanization activator.

[0017] Preferably, the rubber composition comprises the following raw materials in parts by weight: 100 parts of diene rubber, 0-1.5 parts of tetrazine compound, 0.2-1.5 parts of pyrazolone compound, 1-30 parts of liquid rubber, 20-100 parts of reinforcing filler, 0-5 parts of silane coupling agent, and 2-10 parts of vulcanization activator.

[0018] Preferably, the rubber composition comprises the following raw materials in parts by weight: 100 parts of diene rubber, 0.2-1.5 parts of tetrazine compound, 0.2-1.5 parts of pyrazolone compound, 1-30 parts of liquid rubber, 20-100 parts of reinforcing filler, 0-5 parts of silane coupling agent, and 2-10 parts of vulcanization activator.

[0019] In this application, the sulfidation activator is zinc oxide and stearic acid.

[0020] It is worth noting that tetrazine compounds can undergo a trans-Diels-Alder reaction with the double bonds of synthetic diene rubbers, thus reducing heat generation. Pyrazolone compounds can complex with zinc oxide to form a weak sacrificial bond network, improving the rubber's resistance to damage. The combined use of tetrazine and pyrazolone compounds can both reduce heat generation in synthetic rubber and improve the cut resistance of the compound, with a certain synergistic effect. Liquid rubbers containing specific functional groups, when added alone, can improve resistance to damage to some extent, but the hysteresis loss or heat generation remains unchanged. However, when added together, they have a synergistic effect with pyrrolidone, significantly improving resistance to damage while also reducing heat generation to some extent. This application can significantly reduce heat generation in OTR engineering tires while improving their resistance to damage.

[0021] Furthermore, the rubber composition also includes a vulcanization accelerator, a vulcanizing agent, an antioxidant, a resin, and a plasticizer.

[0022] In this application, the vulcanization accelerator is one or more of the following: thiazoles, thiurams, sulfenamides, dithiocarbamates, xanthic acids, guanidines, and thioureas. Preferably, it is one or more of diphenylguanidine and N-cyclohexyl-2-benzothiazole sulfenamides. The vulcanization accelerator accounts for 0.5-4 parts by weight in the rubber composition, preferably 0.8-3 parts, and more preferably 1-2.5 parts.

[0023] The vulcanizing agent is sulfur, and the weight percentage of the vulcanizing agent in the rubber composition is 0.5-5 parts, preferably 0.8-3 parts, and more preferably 1-2 parts.

[0024] Furthermore, the antioxidant 6PPD, dicyclopentadiene DCPD resin, and plasticizer selected in this application are used.

[0025] In this application, the rubber composition further includes the protective agent microcrystalline wax.

[0026] Furthermore, the diene rubber is one or more of the following: modified or unmodified natural rubber, polyisoprene rubber, polybutadiene rubber, cis-butadiene rubber, styrene-butadiene copolymer rubber, ethylene-propylene-diene monomer copolymer, styrene-isoprene-styrene terblock copolymer rubber, and styrene-butadiene-styrene terblock copolymer rubber.

[0027] Furthermore, the diene rubber is composed of 50-100 parts by weight of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber, and 0-50 parts by weight of one or more of modified or unmodified natural rubber and polyisoprene rubber.

[0028] Preferably, the diene rubber is composed of 60-100 parts by weight of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber, and 0-40 parts by weight of one or more of modified or unmodified natural rubber and polyisoprene rubber.

[0029] In this application, the styrene-butadiene copolymer rubber contains 5%-40% wt styrene, and the styrene-butadiene copolymer rubber is composed of one or more of the following elastomer substances: unmodified solution-polymerized styrene-butadiene rubber, unmodified emulsion-polymerized styrene-butadiene rubber, end-group modified solution-polymerized styrene-butadiene rubber, end-group modified emulsion-polymerized styrene-butadiene rubber, main-chain modified solution-polymerized styrene-butadiene rubber, and main-chain modified emulsion-polymerized styrene-butadiene rubber.

[0030] It is worth noting that using the aforementioned rubber can both reduce tire heat generation and improve resistance to damage.

[0031] Considering that emulsion styrene-butadiene rubber has a high molecular weight and strong resistance to damage, in some embodiments, emulsion styrene-butadiene rubber is preferred among styrene-butadiene rubbers. After modification with the addition of tetrazine and pyrazolone compounds, it achieves a better balance of cut resistance, heat generation, and processing performance.

[0032] In other embodiments, nickel-catalyst, lithium-catalyst, or rare-earth-catalyst systems are preferred in the polybutadiene rubber. The addition of modified polybutadiene rubber can effectively balance wear resistance, heat generation, processing performance, aging resistance, and fatigue crack propagation performance.

[0033] Furthermore, the tetrazine compound is one or more of 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine, 3,6-bis(3-pyridyl)-1,2,4,5-tetrazine, and 3,6-bis(4-pyridyl)-1,2,4,5-tetrazine, and the tetrazine compound accounts for 0.3-1.2 parts by weight in the rubber composition.

[0034] In this application, the tetrazine compound is preferably 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine, and its proportion in the rubber composition is preferably 0.3-1 parts by weight, more preferably 0.3-0.8 parts by weight.

[0035] Furthermore, the pyrazolone compound is one or a combination of 3-methyl-5-pyrazolone, 3-phenyl-5-pyrazolone, 3-ethyl-5-pyrazolone, 3-propyl-5-pyrazolone, and 3-butyl-5-pyrazolone, and the proportion of the pyrazolone compound in the rubber composition is 0.3-1.2 parts by weight.

[0036] In this application, the pyrazolone compound is preferably a combination of one or more of 3-methyl-5-pyrazolone and 3-phenyl-5-pyrazolone, more preferably 3-methyl-5-pyrazolone. The proportion of the pyrazolone compound in the rubber composition is preferably 0.3-1 parts by weight, more preferably 0.3-0.8 parts by weight.

[0037] Furthermore, the liquid rubber is one or more of the following: modified or unmodified liquid polyisoprene, liquid hydrogenated polyisoprene, liquid polybutadiene, liquid styrene-isoprene copolymer, liquid isoprene-butadiene copolymer, and liquid styrene-butadiene copolymer, and the molecular weight of the liquid rubber is 500-100000 g / mol, and the proportion of the liquid rubber in the rubber composition is 3-20 parts by mass.

[0038] In this application, the liquid rubber is preferably a combination of one or more of the following: maleic anhydride-modified liquid polyisoprene, carboxylic acid acrylate-modified liquid polyisoprene, maleic anhydride-modified liquid polybutadiene, carboxylic acid acrylate-modified liquid polybutadiene, and maleic anhydride monomethyl ester-modified liquid polyisoprene; more preferably, a combination of one or more of the following: maleic anhydride-modified liquid polyisoprene, carboxylic acid acrylate-modified liquid polyisoprene, and maleic anhydride monomethyl ester-modified liquid polyisoprene. The molecular weight of the liquid rubber is preferably 500-80000 g / mol, more preferably 500-50000 g / mol. The proportion of the liquid rubber in the rubber composition is preferably 5-15 parts by weight, more preferably 5-10 parts by weight.

[0039] It is worth noting that this application employs the aforementioned tetrazine compounds, pyrazolone compounds, styrene-butadiene rubber, and natural rubber for graft modification, thereby improving filler dispersion, reducing heat generation, and enhancing the final product's resistance to damage. After the addition of liquid rubber, a synergistic effect occurs with the tetrazine compounds and pyrazolone compounds, further reducing heat generation and improving resistance to cuts and tears.

[0040] Furthermore, the reinforcing filler is one or more of the following: modified or unmodified carbon black, acetylene black, silica, carbon nanotubes, graphite, and graphene.

[0041] The silane coupling agent is one or a combination of bis-[3-(triethoxysilane)propyl]-tetrasulfide (Si 69), bis-[3-(triethoxysilane)propyl]-disulfide (Si 75), 3-octanoylthio-1-propyltriethoxysilane (NXT), γ-mercaptopropylethoxybis-(propane-hexaethoxysiloxane) (Si 747), and mercaptoalkoxy-ethoxysilane (Si 363).

[0042] In this application, the preferred reinforcing filler is one or a combination of carbon black and silica.

[0043] In some embodiments, the reinforcing filler is composed of 20-70 parts by weight of carbon black and 0-30 parts by weight of silica; preferably, it is composed of 20-60 parts by weight of carbon black and 0-25 parts by weight of silica; more preferably, it is composed of 30-60 parts by weight of carbon black and 0-20 parts by weight of silica.

[0044] Furthermore, the specific surface area of ​​the carbon black is 20-160 m². 2 / g, the specific surface area of ​​silica is 60-250m². 2 / g. More preferably, the specific surface area of ​​the carbon black is 40-140m². 2 / g, the specific surface area of ​​silica is 90-200m² 2 / g.

[0045] In this application, the carbon black is one or a combination of N110, N121, N134, N220, N231, N234, N242, N293, N299, N315, N326, N330, N332, N339, N343, N347, N351, N358, N375, N539, N550, N582, N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990, and N991; the iodine absorption value of the above carbon black is 5-150 g / kg, and the DBP absorption value is 30-150 cm⁻¹. 3 / 100g.

[0046] In this application, the silane coupling agent is preferably one or a combination of bis-[3-(triethoxysilyl)propyl]-tetrasulfide (Si 69), bis-[3-(triethoxysilyl)propyl]-disulfide (Si 75), and 3-octanoylthio-1-propyltriethoxysilane (NXT), more preferably bis-[3-(triethoxysilyl)propyl]-disulfide (Si 75) or 3-octanoylthio-1-propyltriethoxysilane (NXT). The proportion of the silane coupling agent in the rubber composition is preferably 0-4 parts by weight, more preferably 0-3 parts by weight.

[0047] It is worth noting that by adjusting the types and amounts of carbon black, silica, and silane coupling agent, this application can better balance the low heat generation and improve the damage resistance of the final product.

[0048] The second objective of this application is to provide a method for preparing a rubber composition as described above.

[0049] A method for preparing the rubber composition as described above includes the following steps:

[0050] Step (1) Accurately weigh diene rubber, tetrazine compounds, pyrazolone compounds, liquid rubber, reinforcing filler, silane coupling agent, vulcanization accelerator, vulcanizing agent, antioxidant, vulcanization activator, resin and plasticizer;

[0051] Step (2) Mix a portion of diene rubber, tetrazine compound, antioxidant and reinforcing filler and react them at 120-180℃ for 60-300 seconds. After standing and cooling, material A is obtained, wherein the discharge temperature is 120-180℃.

[0052] Step (3) Mix the remaining diene rubber, pyrazolone compounds, liquid rubber, silane coupling agent, vulcanization activator, resin and plasticizer with material A, and react them at 120-180℃ for 60-300 seconds. After standing and cooling, material B is obtained, wherein the discharge temperature is 120-180℃.

[0053] Step (4) The vulcanizing agent and vulcanization accelerator are added to material B and then discharged after mixing to obtain the rubber composition.

[0054] In this application, tetrazine compounds are added in step (2), pyrazolone compounds and liquid rubber are all added in step (3), and antioxidants may be added partially or entirely in step (2), step (3), or step (4).

[0055] In some embodiments, the “partial diene rubber” in step (2) is a combination of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber, and the “remaining diene rubber” in step (3) is a combination of one or more of modified or unmodified natural rubber and polyisoprene rubber.

[0056] In some embodiments, carbon black in the reinforcing filler may be added in part or all in step (2) or step (3); silica in the reinforcing filler may be added in part or all in step (2) or step (3); and silane coupling agent may be added in part or all in step (2) or step (3) according to the proportion of silica added.

[0057] In this application, the mixing reaction in step (2) at 120-180℃ is preferably processed for 120-300 seconds, more preferably 150-300 seconds; the discharge temperature is 120-180℃, preferably 130-170℃, more preferably 140-160℃.

[0058] In this application, the mixing reaction in step (3) at 120-180℃ is preferably processed for 120-300 seconds, more preferably 150-300 seconds; the discharge temperature is 120-180℃, preferably 130-170℃, more preferably 140-160℃.

[0059] It is worth noting that by adding small amounts of tetrazine compounds, pyrazolone compounds, and liquid rubber, and by applying an optimized rubber mixing process that conforms to the reaction of tetrazine compounds, pyrazolone compounds, and rubber, the composition can simultaneously reduce the hysteresis loss and heat generation of rubber, and improve its resistance to damage such as cut and tear resistance. The preparation method in this application is simple to operate and highly practical.

[0060] The third objective of this application is to provide a tire.

[0061] An OTR engineered tire comprising the rubber composition described above.

[0062] Compared with the prior art, the rubber composition disclosed in this application reduces the hysteresis loss and heat generation of rubber, and improves the rubber's resistance to damage such as cut and tear resistance, which is a two-way improvement that cannot be achieved by traditional technology. Attached Figure Description

[0063] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0064] Figure 1 shows the high-temperature slow tear energy test specimen provided in this application. Detailed Implementation

[0065] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0066] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in the embodiments of this application, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in this application is merely for describing particular implementations and is not intended to limit the scope of this disclosure.

[0067] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; other experimental methods and technical means not specifically mentioned herein refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0068] To better illustrate the content of this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail in order to highlight the main points of this application.

[0069] Without conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of this application.

[0070] This application provides a rubber composition and its preparation method, as well as an OTR tire using the same. The rubber composition (by mass parts) comprises 100 parts of diene rubber, 0-1.5 parts of a tetrazine compound, 0.2-1.5 parts of a pyrazolone compound, 0-30 parts of liquid rubber, 20-100 parts of reinforcing filler, 0-5 parts of a silane coupling agent, 2-10 parts of a vulcanization activator, a vulcanization accelerator, a vulcanizing agent, an antioxidant, a resin, and a plasticizer. The proportions of the tetrazine compound and the liquid rubber are not simultaneously zero. This application can significantly reduce heat generation in OTR engineering tires while improving the tire's resistance to damage.

[0071] To better understand this application, the following embodiments are provided for further detailed explanation, but they should not be construed as limiting the application. Any non-essential improvements and adjustments made by those skilled in the art based on the above application content are also considered to fall within the protection scope of this application.

[0072] The standards and methods for testing the rubber composition in this application are as follows in the following embodiments:

[0073] 1) Mooney viscosity: Refer to ASTM D1646-2007, test conditions are ML(1+4) 100℃. The higher the index, the higher the Mooney viscosity.

[0074] 2) Mooney scorch: According to ASTM D1646-2007, the test temperature is 130℃. The higher the index, the longer the scorch time.

[0075] 3) Hardness: Shore hardness test, refer to ASTM D2240-2010. The higher the index, the higher the hardness.

[0076] 4) MA100: 100% tensile modulus test, referring to ASTM D412-2006, taking the modulus at 100% elongation, the test environment temperature is 23±2℃. The larger the index, the higher the tensile modulus.

[0077] 5) Tensile strength and elongation at break: Refer to ASTM D412-2006. The sample is dumbbell-shaped. The test speed is 500 mm / min, and the test environment temperature is 23±2℃. The larger the index, the higher the tensile strength.

[0078] 6) Hysteresis Loss Factor: Tested using Metravib DMA at 60°C, 10Hz, dynamic deformation 0.07%-50%, and in planar shear mode. The smaller the index, the smaller the hysteresis loss, and the lower the rolling resistance and heat generation.

[0079] 7) High-temperature slow-speed tear energy: A sample with a width of 40 mm, a height of 65 mm, and a notch of 10 mm was used (see Figure 1). The test speed was 50 mm / min, and the test environment temperature was 100 ± 5℃. The higher the index, the higher the high-temperature tear energy and the better the tear resistance.

[0080] 8) Dynamic cutting loss of rubber: Manufacturer: Beijing Wanhui Yifang; Test conditions: Impact frequency 120 / min; Rubber wheel speed 720rpm; Test method: The mass after 5min of pre-cutting of the rubber wheel is recorded as m0, and the mass after 20min of cutting is recorded as m1; Data record: Cutting loss mass per minute: Δm=(m0-m1) / 15min; Where the smaller the index, the smaller the cutting mass loss and the better the cutting resistance and tear resistance.

[0081] The raw materials used in this application embodiment are as follows:

[0082] Natural Rubber: TSR20, Sinochem International (Holdings) Co., Ltd.

[0083] SBR1502 (Styrene-Butadiene Rubber) Shenhua Chemical Industry Co., Ltd.

[0084] BR9000 (Polybutadiene Rubber) Sinopec Qilu Petrochemical Company

[0085] Tetraazine compounds: 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, Otsuka Chemical Co., Ltd.

[0086] Pyrazolone compounds: 3-methyl-5-pyrazolone, TISA (Shanghai) Chemical Industry Development Co., Ltd.

[0087] Liquid Rubber: Maleic Anhydride Monomethyl Ester Modified Liquid Polyisoprene, Kuraray Corporation

[0088] HD165MP (Silica) Wuxi Quecheng Silicon Co., Ltd.

[0089] N234, N220, N330, N115: Cabot Carbon Black

[0090] Si 69: Nanjing Shuguang Chemical Group Co., Ltd.

[0091] Si 75: Nanjing Shuguang Chemical Group Co., Ltd.

[0092] EP-140: Dicyclopentadiene DCPD resin, JXTG Corporation, Japan

[0093] 6PPD (Antioxidant): Shandong Shangshun Chemical Co., Ltd.

[0094] Stearic acid: Sichuan Tianyu Oil & Chemical Co., Ltd.

[0095] Zinc oxide: Dalian Zinc Oxide Co., Ltd.

[0096] Microcrystalline wax: Yanggu Huatai Chemical Co., Ltd.

[0097] NS (N-tert-butyl-2-benzothiazole sulfenamide): Shandong Shangshun Chemical Co., Ltd.

[0098] Sulfur: Shandong Shangshun Chemical Co., Ltd.

[0099] Example 1

[0100] The raw materials used in Comparative Examples 1-1 to 1-3 and Examples 1-1 to 1-5 of this application are shown in the table below, all in parts by mass. Examples 1-1 to 1-5 are rubber compositions using 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine and 3-methyl-5-pyrazolone together. Comparative Examples 1-2 and 1-3 are rubber compositions using 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine and 3-methyl-5-pyrazolone individually.

[0101] Table 1: Formulations of Comparative Examples 1-1 to 1-3 and Examples 1-1 to 1-5

[0102] The above schemes all adopt the following preparation method:

[0103] Step (1) Weigh the raw materials according to the above weight; Step (2) Mix SBR1502 rubber for 30 seconds, add tetrazine compound, 10 parts carbon black N220 and antioxidant 6PPD, and perform a mixing reaction at 130-150℃ for 150 seconds, then discharge the rubber at 150℃ to obtain material A; Step (3) Mix the remaining raw materials except for vulcanizing agent and vulcanization accelerator with material A, perform a mixing reaction at 140-160℃ for 150 seconds, and discharge the rubber at 160℃ to obtain material B; Step (4) Add vulcanizing agent and vulcanization accelerator to material B and mix in a mixer for about 180 seconds, then discharge the material at 110℃ to obtain a rubber composition for reducing heat generation in OTR engineering tires while improving their anti-damage performance. Then, vulcanize the obtained rubber composition at 150℃ for 30 minutes for testing.

[0104] Performance tests were conducted on Examples 1-1, 1-2, 1-3, 1-4, 1-5 and Comparative Examples 1-1, 1-2, 1-3 before and after aging at 100℃ for 72 hours. The results are shown in Table 2 below.

[0105] Table 2: Performance Comparison of Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-3 *The test results for the rubber composition are expressed in exponential form.

[0106] The calculation formula is: Test item = (Example / Comparative Example 1-1) × 100.

[0107] Compared to Comparative Example 1-1, Examples 1-1 to 1-5, with minimal change in hardness, showed a decrease in tensile strength, a slight increase in elongation at break, a 20-40% increase in slow-speed tear performance at 100°C, a 17-24% reduction in hysteresis loss, and a 12-19% reduction in cutting loss. Comparative Example 1-2 showed a 25% reduction in cutting loss and a 50% increase in slow-speed tear performance at high temperature, but a worsening of hysteresis loss. Similarly, Comparative Example 1-3 showed a 20% reduction in hysteresis loss and a 22% increase in slow-speed tear performance at high temperature, but a 7% decrease in cutting loss. After 3 days of thermo-oxidative aging in a 100℃ oven, the tensile strength of Examples 1-1 to 1-5 did not change much, the elongation was slightly improved, the high-temperature tear resistance at 100℃ was improved by about 40%, the dynamic cutting loss was reduced to 15-20%, and the hysteresis loss was reduced by 15%-23%. Therefore, when 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine and 3-methyl-5-pyrazolone are used together in tires, they can improve the resistance to damage (cut resistance, tear resistance) and reduce heat generation.

[0108] Example 2

[0109] The raw materials used in Comparative Examples 2-1 to 2-4 and Examples 2-1 to 2-4 of this application are shown in Table 3 below, all in parts by mass. Among them, Comparative Examples 2-2 and 2-3 are compositions of liquid polyisoprene modified with different amounts of maleic anhydride monomethyl ester; Comparative Example 2-4 is a rubber composition using only 3-methyl-5-pyrazolone; Examples 2-1 and 2-2 are rubber compositions using 3-methyl-5-pyrazolone and maleic anhydride monomethyl ester modified liquid polyisoprene together; Example 2-3 is a rubber composition using 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine and 3-methyl-5-pyrazolone together; Example 2-4 is a rubber composition using 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, 3-methyl-5-pyrazolone and maleic anhydride monomethyl ester modified liquid polyisoprene together.

[0110] Table 3: Formulations of Comparative Examples 2-1 to 2-4 and Examples 2-1 to 2-4

[0111] The above schemes all adopt the following preparation method:

[0112] Step (1) Weigh the raw materials according to the above weight; Step (2) Mix SBR1502 and rubber for 30 seconds, add tetrazine compound, 10 parts carbon black N220 and antioxidant 6PPD, and mix and react at 130-150℃ for 150 seconds, and discharge the rubber at 150℃ to obtain material A; Step (3) Mix STR20, 3-methyl-5-pyrazolone, maleic anhydride monomethyl ester modified liquid polyisoprene, and other raw materials other than vulcanizing agent and vulcanization accelerator with material A, mix and react at 140-160℃ for 150 seconds, and discharge the rubber at 160℃ to obtain material B; Step (4) Add vulcanizing agent and vulcanization accelerator to material B and mix in a mixer for about 180 seconds, and discharge at 110℃ to obtain a rubber composition for reducing heat generation of OTR engineering tires and improving their anti-damage performance. The obtained rubber composition was then vulcanized at 150°C for 30 minutes for testing.

[0113] Performance tests were conducted on Comparative Examples 2-1 to 2-4 and Examples 2-1 to 2-4 after aging at 100°C for 72 hours without aging. The results are shown in Table 4 below.

[0114] Table 4: Comparison of performance results between Comparative Examples 2-1 to 2-4 and Examples 2-1 to 2-4 *The test results for the rubber composition are expressed in exponential form.

[0115] The calculation formula is: Test item = (Example / Comparative Example 2-1) × 100.

[0116] Compared to Comparative Example 2-1, Comparative Examples 2-2, 2-3, and 2-4, with minimal change in hardness, showed improved high-temperature slow-speed tear energy by 19%, 21%, and 40%, respectively, and reduced cutting loss by 13%, 15%, and 14%, respectively, while hysteresis loss remained largely unchanged or slightly increased. Examples 2-1 to 2-2 showed improved elongation by 39% and 49%, respectively, and high-temperature slow-speed tear energy by 400%-500%, with significant improvements even after 3 days of thermo-oxidative aging in a 100°C oven. Examples 2-3 and 2-4 showed improved tensile strength, significantly increased elongation at break, and significantly improved high-temperature tear energy by 36% and 47%, respectively, with reduced cutting loss by approximately 10-15% and hysteresis loss by 18-16%. Therefore, the combined use of 3-methyl-5-pyrazolone and maleic anhydride monomethyl ester-modified liquid polyisoprene significantly improves the rubber's resistance to damage and reduces heat generation to some extent when applied in tires. When liquid polyisoprene modified with 3-methyl-5-pyrazolone, 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, and maleic anhydride monomethyl ester is used in tires, it can significantly improve the rubber's resistance to damage and significantly reduce heat generation.

[0117] Example 3

[0118] The raw materials used in Comparative Example 3-1 and Examples 3-1, 3-2, 3-3, and 3-4 of this application are shown in Table 5 below, all in parts by mass. Examples 3-1 and 3-3, compared to Comparative Example 3-1, include rubber compositions containing 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine and 3-methyl-5-pyrazolone. Examples 3-2 and 3-4, compared to Comparative Example 3-1, include rubber compositions containing a combination of three compounds: 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, 3-methyl-5-pyrazolone, and maleic anhydride monomethyl ester modified liquid polyisoprene.

[0119] Table 5: Formulations of Comparative Example 3-1 and Examples 3-1 to 3-4

[0120] The above schemes all adopt the following preparation method:

[0121] Step (1) Weigh the raw materials according to the above weight; Step (2) Mix SBR1502 rubber for 30 seconds, add tetrazine compound, 10 parts carbon black N220 and antioxidant 6PPD, and perform a mixing reaction at 130-150℃ for 150 seconds, then discharge the rubber at 150℃ to obtain material A; Step (3) Mix the remaining raw materials except for vulcanizing agent and vulcanization accelerator with material A, perform a mixing reaction at 140-160℃ for 120 seconds, and discharge the rubber at 160℃ to obtain material B; Step (4) Add vulcanizing agent and vulcanization accelerator to material B and mix in a mixer for about 180 seconds, then discharge the material at 110℃ to obtain a rubber composition for reducing heat generation of OTR engineering tires on harsh road surfaces while improving their resistance to damage. Then, vulcanize the obtained rubber composition at 150℃ for 30 minutes for testing.

[0122] Performance tests were conducted on Examples 3-1, 3-2, 3-3, 3-4 and Comparative Example 3-1, respectively, for unaged and aged at 100℃ for 72 hours. The results are shown in Table 6 below.

[0123] Table 6: Performance Comparison of Examples 3-1 to 3-4 and Comparative Example 3-1 *The test results for the rubber composition are expressed in exponential form.

[0124] The calculation formula is: Test item = (Example / Comparative Example 3-1) × 100.

[0125] Compared to Comparative Example 3-1, Examples 3-1 and 3-3, with almost unchanged hardness, showed increases in elongation at break of 20% and 18%, respectively, significant reductions in hysteresis loss of 15% and 21%, and reductions in shear loss of 10% and 8%, respectively. This demonstrates that the higher the amount of 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine added, the greater the reduction in heat generation, but the worse the shear loss becomes. This trend was also observed after 3 days of thermo-oxidative aging in a 100°C oven. Therefore, the combined use of 3-methyl-5-pyrazolone and 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine in this OTR engineering tire formulation can both improve the rubber's resistance to damage and reduce heat generation.

[0126] Compared with Examples 3-1 and 3-3, Examples 3-2 and 3-4 added maleic anhydride monomethyl ester modified liquid polyisoprene, increasing the elongation to 134% and 126% respectively, reducing the shear loss to 84% and 86% respectively, and the hysteresis loss to 83% and 74% respectively. Therefore, the combined use of 3-methyl-5-pyrazolone, 3,6-bis(2-pyridyl)-1,2,4,5-tetraazine, and maleic anhydride monomethyl ester modified liquid polyisoprene can significantly improve the rubber's resistance to damage and reduce heat generation when applied in this OTR engineering tire formulation.

[0127] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A rubber composition, characterized in that, The raw materials comprise the following parts by weight: 100 parts diene rubber, 0-1.5 parts tetrazine compound, 0.2-1.5 parts pyrazolone compound, 0-30 parts liquid rubber, 20-100 parts reinforcing filler, 0-5 parts silane coupling agent, and 2-10 parts vulcanization activator, wherein the proportions of the tetrazine compound and the liquid rubber are not simultaneously zero; wherein, The structure of the tetrazine compound is as follows: Where X 1 X 2 This indicates a heterocyclic group that can have substituents, which can be alkyl, aralkyl, aryl, or heterocyclic. The structure of the pyrazolone compound is as follows: In this context, R1, R2, R3, and R4 each independently represent a hydrogen atom, alkyl, aralkyl, aryl, or heterocyclic group; R3 and R4 can be linked to form an alkylene group, and any two of R2, R3, and R4 can be linked together to form an alkylene group; R5, R7, and R8 each independently represent a hydrogen atom, alkyl, aralkyl, aryl, or heterocyclic group; R6 represents an alkyl, aralkyl, aryl, or heterocyclic group; and each of these groups can independently have one or more substituents. The structure of the liquid rubber is as follows: Where l, m, and n are any integers from 1 to 1000.

2. The rubber composition according to claim 1, characterized in that, It also includes vulcanization accelerators, vulcanizing agents, antioxidants, resins, and plasticizers.

3. The rubber composition according to claim 1, characterized in that, The diene rubber is one or more of the following: modified or unmodified natural rubber, polyisoprene rubber, polybutadiene rubber, cis-butadiene rubber, styrene-butadiene copolymer rubber, ethylene-propylene-diene monomer copolymer, styrene-isoprene-styrene terblock copolymer rubber, and styrene-butadiene-styrene terblock copolymer rubber.

4. The rubber composition according to claim 3, characterized in that, The diene rubber is composed of 50-100 parts by weight of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber, and 0-50 parts by weight of one or more of modified or unmodified natural rubber and polyisoprene rubber.

5. The rubber composition according to claim 1, characterized in that, The tetrazine compound is one or more of 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine, 3,6-bis(3-pyridyl)-1,2,4,5-tetrazine, and 3,6-bis(4-pyridyl)-1,2,4,5-tetrazine, and the tetrazine compound accounts for 0.3-1.2 parts by weight in the rubber composition.

6. The rubber composition according to claim 1, characterized in that, The pyrazolone compound is one or a combination of 3-methyl-5-pyrazolone, 3-phenyl-5-pyrazolone, 3-ethyl-5-pyrazolone, 3-propyl-5-pyrazolone, and 3-butyl-5-pyrazolone, and the proportion of the pyrazolone compound in the rubber composition is 0.3-1.2 parts by weight.

7. The rubber composition according to claim 1, characterized in that, The liquid rubber is one or more of the following: modified or unmodified liquid polyisoprene, liquid hydrogenated polyisoprene, liquid polybutadiene, liquid styrene-isoprene copolymer, liquid isoprene-butadiene copolymer, and liquid styrene-butadiene copolymer, and the molecular weight of the liquid rubber is 500-100000 g / mol, and the proportion of the liquid rubber in the rubber composition is 3-20 parts by mass.

8. The rubber composition according to claim 1, characterized in that, The reinforcing filler is one or more of the following: modified or unmodified carbon black, acetylene black, silica, carbon nanotubes, graphite, and graphene. The silane coupling agent is one or more of the following: bis-[3-(triethoxysilane)propyl]-tetrasulfide, bis-[3-(triethoxysilane)propyl]-disulfide, 3-octanoylthio-1-propyltriethoxysilane, γ-mercaptopropylethoxybis-(propane-hexaethoxysiloxane), and mercaptoalkoxy-ethoxysilane.

9. The method for preparing the rubber composition according to any one of claims 1-8, characterized in that, Includes the following steps: Step (1) Accurately weigh diene rubber, tetrazine compounds, pyrazolone compounds, liquid rubber, reinforcing filler, silane coupling agent, vulcanization accelerator, vulcanizing agent, antioxidant, vulcanization activator, resin and plasticizer; Step (2) Mix a portion of diene rubber, tetrazine compound, antioxidant and reinforcing filler and react them at 120-180℃ for 60-300 seconds. After standing and cooling, material A is obtained, wherein the discharge temperature is 120-180℃. Step (3) Mix the remaining diene rubber, pyrazolone compounds, liquid rubber, silane coupling agent, vulcanization activator, resin and plasticizer with material A, and react them at 120-180℃ for 60-300 seconds. After standing and cooling, material B is obtained, wherein the discharge temperature is 120-180℃. Step (4) involves adding vulcanizing agent and vulcanization accelerator to material B, mixing and then discharging to obtain the rubber composition.

10. An OTR engineering tire, characterized in that, Includes the rubber composition as described in any one of claims 1-8.

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