Rubber composition and preparation method therefor, and truck tire using same

Abstract

The present application belongs to the technical field of rubber, and particularly relates to a rubber composition and a preparation method therefor, and a truck tire using same. The rubber composition comprises, in parts by mass: 100 parts of diene rubber, 0.2-1.5 parts of a hydrazide compound, 0.2-1.5 parts of a pyrazolone compound, 0-30 parts of liquid rubber, 20-120 parts of a reinforcing filler, 0-10 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 present application can significantly reduce the heat generation of the tire while improving its cut resistance and tear resistance, thereby enhancing the damage resistance of the truck tire.

Description

A rubber composition and its preparation method, and a heavy-duty tire using the same.

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411578924X, filed on November 7, 2024, entitled "A rubber composition and a method for preparing the same, and a heavy-duty tire using the same", and Chinese Patent Application No. 2025106921408, filed on May 27, 2025, entitled "A rubber composition and a method for preparing the same, and a heavy-duty 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 a heavy-duty tire using the same. Background Technology

[0004] During operation, heavy-duty engineering vehicles expose their tires to heat, oxygen, fatigue, and cutting damage under load and cyclic deformation. Reducing tire heat generation and improving the tire rubber's cut and tear resistance are crucial for extending tire lifespan. However, traditional methods, such as changing the type of rubber or increasing the amount of silica used, to reduce tire heat generation have many limitations in achieving a balanced overall performance. Low heat generation requires low energy dissipation (hysteresis loss) in the rubber material, while cut and tear resistance under large deformation requires high energy dissipation capacity. 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, increasing the amount of silica or decreasing the amount of filler in the rubber composition can reduce tire heat generation, but it decreases cut and tear resistance, leading to delamination problems such as chipping, breakage, or gaps in the tire's surface, thus affecting its lifespan. Therefore, achieving both low heat generation and high cut and tear resistance simultaneously is quite difficult at present.

[0005] To address this technological need, patent publication number CN112533991B discloses rubber compositions, rubber materials and their uses, as well as additives represented by general formulas (2) and (3), which can exhibit low heat generation, tear strength and durability. Similarly, tires made from this rubber composition have weak resistance to cuts and tears.

[0006] Patent publication number CN102257056A discloses a rubber composition, a rubber material containing multiple diene rubbers, an inorganic filler content greater than 50%, additives, and their application methods. While the use of dihydrazide compounds alone can significantly reduce the heat generation properties of the rubber composition, it lacks descriptions and examples regarding cut and tear resistance. Therefore, given the inherent contradiction between low heat generation and cut and tear resistance, this rubber composition cannot meet the requirements for both low heat generation and improved cut and tear resistance in tire applications.

[0007] Patent publication number CN103261300A discloses a rubber composition with a carbon black content greater than 50%. This composition is obtained by mixing natural rubber and carbon black in a liquid phase and adding a dihydrazide compound, resulting in a highly dispersed, low-heat-generating composition. However, it lacks descriptions and examples regarding cut and tear resistance. Therefore, given the inherent contradiction between low heat generation and cut and tear resistance, this rubber composition cannot meet the requirements for both low heat generation and improved cut and tear resistance in tire applications.

[0008] Patent publication number CN111592695A discloses a rubber composition consisting of 0-40 parts of natural rubber with the addition of the low rolling resistance additive 1-naphthylacetylhydrazine, high-cis-butadiene rubber or solution-polymerized styrene-butadiene rubber, fillers, and additives. The primary purpose is to achieve low rolling resistance or low hysteresis without affecting abrasion performance. However, it lacks descriptions and examples regarding cut and tear resistance. Therefore, given the inherent contradiction between low heat generation and high cut and tear resistance, this rubber composition cannot meet the requirements for low heat generation in tires while simultaneously improving cut and tear resistance.

[0009] Patent publication number CN113652012A discloses a rubber composition for tire base rubber containing carbon black dispersant isophthalohydrazide and a large amount of thermally conductive filler to reduce heat generation and improve thermal conductivity. However, it does not describe or provide example data regarding cut and tear resistance. Therefore, given the contradiction between low heat generation and cut and tear resistance, this rubber composition cannot meet the requirements of tires for both low heat generation and improved cut and tear resistance.

[0010] Therefore, achieving both low heat generation and high cut and tear resistance simultaneously is quite difficult at present.

[0011] Therefore, how to provide a rubber composition that reduces heat generation while improving cut resistance and damage resistance, and its preparation method, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0012] In view of this, the first objective of this application is to provide a rubber composition that reduces heat generation while improving cut resistance and damage resistance, addressing the problems existing in the prior art.

[0013] To achieve the above objectives, this application adopts the following technical solution:

[0014] A rubber composition comprising the following raw materials in parts by weight: 100 parts of diene rubber, 0.2-1.5 parts of acylhydrazine compound, 0.2-1.5 parts of pyrazolone compound, 0-30 parts of liquid rubber, 20-120 parts of reinforcing filler, 0-10 parts of silane coupling agent, and 2-10 parts of vulcanization activator; wherein,

[0015] The structure of the acylhydrazine compound is: X 1 -CO-NH-NH2 (1) NH2-NH-CO-X 2 -CO-NH-NH2 (2) X 3 -CO-NH-N= X 4 (3)

[0016] Where X 1 X 2 X 3 X 4 Independently selected from: aromatic hydrocarbon groups having 6 to 30 carbon atoms or alkane groups having 6 to 30 carbon atoms; wherein the aromatic hydrocarbon is optionally substituted with an alkyl, hydroxyl, or amino group having 1 to 20 carbon atoms;

[0017] The structure of the pyrazolone compound is as follows:

[0018] In this group, R1, R2, R3, and R4 each independently represent a hydrogen atom, alkyl, aralkyl, aryl, or heterocyclic group; R3 and R4 can be connected to form an alkylene group, and any two of R2, R3, and R4 can be connected 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, which are alkyl, aralkyl, aryl, or heterocyclic groups.

[0019] The structure of the liquid rubber is as follows:

[0020] Where l, m, and n are any integers from 1 to 1000.

[0021] In this application, the sulfidation activator is zinc oxide and stearic acid.

[0022] It is worth noting that acylhydrazide compounds can react with natural rubber to reduce 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 acylhydrazide 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, but the hysteresis loss or heat generation remains almost unchanged. However, when added in combination, they significantly improve resistance to damage and reduce heat generation to some extent. This application can significantly reduce tire heat generation while improving tire cut and tear resistance, thereby enhancing the tire's resistance to damage.

[0023] Furthermore, the rubber composition also includes a vulcanization accelerator, a vulcanizing agent, an antioxidant, a vulcanization activator, a resin, and a plasticizer.

[0024] 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 by weight, and more preferably 1-2.5 parts by weight.

[0025] The vulcanizing agent is sulfur, and the proportion of the vulcanizing agent in the rubber composition is 0.5-5 parts by weight, preferably 0.8-3 parts by weight, and more preferably 1-2 parts by weight.

[0026] Furthermore, 6PPD is selected as the antioxidant in this application. The rubber composition also includes the protective agent microcrystalline wax.

[0027] 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.

[0028] Furthermore, the diene rubber is composed of 50-100 parts by weight of one or more of modified or unmodified natural rubber and polyisoprene rubber, and 0-50 parts by weight of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber.

[0029] Preferably, the diene rubber is composed of 60-100 parts by weight of one or more of modified or unmodified natural rubber and polyisoprene rubber, and 0-40 parts by weight of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber.

[0030] 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. The Tg of the styrene-butadiene copolymer rubber is -100 to 0°C, more preferably -90 to -15°C, and even more preferably -80 to -30°C.

[0031] It is worth noting that using the aforementioned rubbers can simultaneously reduce tire heat generation and improve cut and tear resistance. Furthermore, emulsion styrene-butadiene rubber is preferred among styrene-butadiene rubbers because it has a high molecular weight and strong resistance to damage. After modification with pyrazolone compounds, it achieves a better balance between cut resistance, heat generation, and processing performance. Among polybutadiene rubbers, nickel-catalyzed, lithium-catalyzed, and rare-earth-catalyzed systems are more preferred. The addition of modified polybutadiene rubber can effectively balance wear resistance, rolling resistance, heat generation, processing performance, and resistance to aging and fatigue crack propagation.

[0032] Furthermore, the acylhydrazine compound is one or more of the following: adipate dihydrazine, isophthalic acid dihydrazine, terephthalic acid dihydrazine, caprylic acid dihydrazine, sebacic acid dihydrazine, dodecanoic acid dihydrazine, benzoic acid dihydrazine, naphthoic acid dihydrazine, propionic acid dihydrazine, caprylic acid dihydrazine, stearic acid dihydrazine, hexanoic acid dihydrazine, decanoic acid dihydrazine, oleic acid dihydrazine, lauryl acid dihydrazine, palmitic acid dihydrazine, N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthoic acid dihydrazine, 2-hydroxy-naphthoic acid dihydrazine, and 2-hydroxy-benzoic acid dihydrazine, and the proportion of the acylhydrazine compound in the rubber composition is 0.3-1.2 parts by mass.

[0033] In this application, the acylhydrazide compound is preferably a combination of one or more of adipate dihydrazide, isophthalic dihydrazide, and N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, more preferably one or more of isophthalic dihydrazide and N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide. Furthermore, its proportion in the rubber composition is preferably 0.3-1 parts by weight, more preferably 0.3-0.8 parts by weight.

[0034] 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 mass.

[0035] 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.

[0036] 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.

[0037] 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, it is 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.

[0038] It is worth noting that the combination of the above-mentioned acylhydrazine compounds and pyrazolone compounds in this application can graft and modify natural rubber, styrene-butadiene rubber, and cis-butadiene rubber. Furthermore, the liquid rubber and the acylhydrazine compounds and pyrazolone compounds work synergistically to reduce heat generation while improving resistance to cutting and tearing, thereby increasing the service life of the final product.

[0039] Furthermore, the reinforcing filler is one or more of the following: modified or unmodified carbon black, acetylene black, silica, carbon nanotubes, graphite, and graphene.

[0040] The silane coupling agent is one or more of the following: bis-[3-(triethoxysilyl)propyl]-tetrasulfide, bis-[3-(triethoxysilyl)propyl]-disulfide, 3-octanoylthio-1-propyltriethoxysilane, γ-mercaptopropylethoxybis-(propane-hexaethoxysiloxane), mercaptoalkoxy-ethoxy, or methoxysilane, and the proportion of the silane coupling agent in the rubber composition is 0-8 parts by weight.

[0041] In this application, the preferred reinforcing filler is one or a combination of carbon black and silica.

[0042] In some embodiments, the reinforcing filler is composed of 0-50 parts by weight of silica and 0-70 parts by weight of carbon black; preferably, it is composed of 0-40 parts by weight of silica and 20-70 parts by weight of carbon black; more preferably, it is composed of 0-30 parts by weight of silica and 30-60 parts by weight of carbon black.

[0043] 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 90-230m². 2 / g.

[0044] In this application, the carbon black is one or a combination of several 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.

[0045] 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 (Si75), and 3-octanoylthio-1-propyltriethoxysilane (NXT), more preferably one or a combination of bis-[3-(triethoxysilyl)propyl]-disulfide (Si75) and 3-octanoylthio-1-propyltriethoxysilane (NXT). The proportion of the silane coupling agent in the rubber composition is preferably 0-7 parts by weight, more preferably 0-6 parts by weight.

[0046] It is worth noting that this application can better balance the heat generation and anti-destruction properties of the final product by adjusting the types and amounts of silica, carbon black, and silane coupling agents.

[0047] The second objective of this application is to provide a method for preparing a rubber composition as described above.

[0048] A method for preparing the rubber composition as described above includes the following steps:

[0049] Step (1) Accurately weigh diene rubber, hydrazide compounds, pyrazolone compounds, liquid rubber, reinforcing filler, silane coupling agent, vulcanization accelerator, vulcanizing agent, antioxidant, vulcanization activator, resin and plasticizer;

[0050] Step (2) Mix diene rubber, acyl hydrazine compound, pyrazolone compound 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℃.

[0051] Step (3) Mix the remaining raw materials except for the vulcanizing agent and vulcanization accelerator 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℃.

[0052] Step (4) The vulcanizing agent and vulcanization accelerator are added to material B and then discharged after mixing to obtain the rubber composition.

[0053] In this application, all acylhydrazine compounds and pyrazolone compounds are added in step (2), and liquid rubber and antioxidants may be added partially or entirely in step (2), step (3), or step (4).

[0054] In some embodiments, carbon black in the reinforcing filler may be added in part or all in step (2) or step (3); silica and silane coupling agent in the reinforcing filler may be added in step (3).

[0055] In this application, the mixing reaction treatment at 120-180℃ in step (2) is preferably 120-300 seconds, more preferably 150-300 seconds; the discharge temperature is 120-180℃, preferably 130-170℃, more preferably 140-160℃.

[0056] In this application, the mixing reaction treatment at 120-180℃ in step (3) is preferably 120-300 seconds, more preferably 150-300 seconds; the discharge temperature is 120-180℃, preferably 130-170℃, more preferably 140-160℃.

[0057] It is worth noting that, by adding small amounts of acylhydrazine compounds, pyrazolone compounds, and liquid rubber, and applying an optimized rubber mixing process that conforms to the reaction between acylhydrazine compounds, pyrazolone compounds, and rubber, the rubber composition can simultaneously reduce hysteresis loss and heat generation, while also improving resistance to damage, such as cut and tear resistance. The preparation method described in this application is simple to operate and highly practical.

[0058] A third objective of this application is to provide a heavy-duty tire comprising the rubber composition described above.

[0059] Compared with existing technologies, this application achieves a balance between reducing hysteresis loss of the rubber compound and reducing heat generation while improving cut resistance and tear resistance, which is something that traditional technologies cannot achieve. Attached Figure Description

[0060] 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.

[0061] Figure 1 shows the high-temperature slow tear energy test specimen provided in this application. Detailed Implementation

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] This application provides a rubber composition and its preparation method, as well as a heavy-duty tire using the same. The rubber composition (by mass) comprises 100 parts of diene rubber, 0.2-1.5 parts of acylhydrazine compound, 0.2-1.5 parts of pyrazolone compound, 0-30 parts of liquid rubber, 20-120 parts of reinforcing filler, 0-10 parts of silane coupling agent, 2-10 parts of vulcanization activator, vulcanization accelerator, vulcanizing agent, antioxidant, resin, and plasticizer. The acylhydrazine compound can react with natural rubber to reduce heat generation. The pyrazolone compound can complex with zinc oxide to form a weak sacrificial bond network, improving the rubber's resistance to damage. The liquid rubber containing special functional groups, when added alone, improves resistance to damage, but the hysteresis loss or heat generation remains almost unchanged. However, when added together, it significantly improves resistance to damage and reduces heat generation to some extent. This application can significantly reduce tire heat generation while improving the tire's cut resistance and tear resistance, thereby enhancing the resistance to damage of heavy-duty tires.

[0068] 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.

[0069] The standards and methods for testing the rubber composition in this application are as follows in the following embodiments:

[0070] 1) Mooney viscosity: Refer to ASTM D1646-2007, test conditions are ML(1+4) 100℃. The higher the index, the higher the Mooney viscosity.

[0071] 2) Mooney scorch: According to ASTM D1646-2007, the test temperature is 130℃. The higher the index, the longer the scorch time.

[0072] 3) Hardness: Shore hardness test, refer to ASTM D2240-2010. The higher the index, the higher the hardness.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] The raw materials used in this application embodiment are as follows:

[0079] Natural Rubber: TSR20, Sinochem International (Holdings) Co., Ltd.

[0080] NS712 (Styrene-Butadiene Rubber) - ZSE Corporation, Japan

[0081] BR9000 (Polybutadiene Rubber) Sinopec Qilu Petrochemical Company

[0082] Acylhydrazide compound: N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, Otsuka Chemical Co., Ltd.

[0083] Acylhydrazide compounds: isophthalic acid dihydrazide, adipic acid dihydrazide, stearic acid dihydrazide, TCI (Shanghai) Chemical Industry Development Co., Ltd.

[0084] Pyrazolone compounds: 3-methyl-5-pyrazolone, TISA (Shanghai) Chemical Industry Development Co., Ltd.

[0085] Liquid Rubber: Maleic Anhydride Monomethyl Ester Modified Liquid Polyisoprene, Kuraray Corporation

[0086] HD165MP, HD200MP (Silica) - Wuxi Quecheng Silicon Co., Ltd.

[0087] N234, N220, N330, N115: Cabot Carbon Black

[0088] Si69, Si75: Nanjing Shuguang Chemical Group Co., Ltd.

[0089] NXT: Momentive

[0090] 6PPD (Antioxidant) Shandong Shangshun Chemical Co., Ltd.

[0091] Stearic acid: Sichuan Tianyu Oil & Chemical Co., Ltd.

[0092] Zinc oxide: Dalian Zinc Oxide Co., Ltd.

[0093] Microcrystalline wax: Yanggu Huatai Chemical Co., Ltd.

[0094] NS (N-tert-butyl-2-benzothiazole sulfenamide) Shandong Shangshun Chemical Co., Ltd.

[0095] Sulfur: Shandong Shangshun Chemical Co., Ltd.

[0096] Example 1

[0097] The raw materials used in Examples 1-1 to 1-7 and Examples 1-1 to 1-3 of this application are shown in the table below, all in parts by mass. Example 1-1 is a rubber composition using N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone. Examples 1-2 and 1-3 are rubber compositions using N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone, and maleic anhydride monomethyl ester modified liquid polyisoprene.

[0098] Table 1: Formulations of Comparative Example 1-1 and Examples 1-1 to 1-9

[0099] The above schemes all adopt the following preparation method:

[0100] Step (1) Weigh the raw materials according to the above weight; Step (2) Mix the natural rubber for 30 seconds, add hydrazide compounds and pyrazolone compounds, carbon black, and perform a mixing reaction at 130-160℃ for 150 seconds, then discharge the rubber at 160℃ to obtain material A; Step (3) Mix the remaining raw materials (excluding 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 the 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 and improving the anti-damage performance of tires. Then, vulcanize the rubber composition at 150℃ for 30 minutes for performance testing.

[0101] Performance tests were conducted on Comparative Examples 1-1 to 1-7 and Examples 1-1 to 1-3, respectively, for unaged and aged at 100℃ for 72 hours. The results are shown in Table 2 below.

[0102] Table 2: Comparison of performance results between Comparative Examples 1-1 to 1-7 and Examples 1-1 to 1-3

[0103] *The test results for the rubber composition are expressed in exponential form.

[0104] The calculation formula is: Test item = (Example / Comparative Example 1-1) × 100.

[0105] Compared with Comparative Example 1-1, the Mooney viscosity of Comparative Examples 1-2 to 1-7 and Examples 1-1 to 1-3 increased to a certain extent, and the Mooney scorch time became longer. Regarding MA100, it increased in Comparative Examples 1-2 and 1-3, decreased in Comparative Examples 1-4 and 1-5, and remained relatively unchanged in the others; tensile strength and elongation at break also showed little change. Compared with Comparative Example 1-1, the remaining high-temperature slow tear energies at 100°C were significantly improved, with Example 1-1 showing a 245% increase, and Examples 1-2 and 1-3 showing increases of 472% and 300%, respectively. The trend after aging was consistent with that before aging. Compared with Comparative Example 1-1, the hysteresis loss factor decreased by 11% and 14% in Comparative Examples 1-2 and 1-3, respectively; the hysteresis loss factor of Comparative Examples 1-4, 1-5, 1-6, and 1-7 showed little change; the hysteresis loss factor of Example 1-1 decreased by 11%; and the hysteresis loss factors of Examples 1-2 and 1-3 decreased by 13% and 14%, respectively. Therefore, when N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone are used in tires, they can both reduce heat generation and improve resistance to damage. The combination of N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone, and maleic anhydride monomethyl ester-modified liquid polyisoprene can significantly improve resistance to damage while ensuring reduced heat generation.

[0106] Example 2

[0107] The raw materials used in Comparative Examples 2-1 to 2-7 and Examples 2-1 to 2-3 of this application are shown in Table 3 below, all in parts by mass. Example 2-1 is a rubber composition using N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone. Examples 2-2 and 2-3 are rubber compositions using N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone, and maleic anhydride monomethyl ester modified liquid polyisoprene.

[0108] Table 3: Formulations of Comparative Examples 2-1 to 2-7 and Examples 2-1 to 2-3

[0109] The above schemes all adopt the following preparation method:

[0110] Step (1) Weigh the raw materials according to the above weight; Step (2) Mix natural rubber and SBR1502 for 30 seconds, add hydrazide compounds and pyrazolone compounds, carbon black, and perform a mixing reaction at 140-160℃ for 150 seconds, then discharge the rubber at 160℃ to obtain material A; Step (3) Mix the remaining raw materials except for the 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 the 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 tires that reduces heat generation and improves resistance to damage. Then, vulcanize the rubber composition at 150℃ for 30 minutes for performance testing.

[0111] Performance tests were conducted on Comparative Examples 2-1 to 2-7 and Examples 2-1 to 2-3, respectively, after aging without aging and after aging at 100°C for 72 hours. The results are shown in Table 4 below.

[0112] Table 4: Comparison of performance results between Comparative Examples 2-1 to 2-7 and Examples 2-1 to 2-3

[0113] *The test results for the rubber composition are expressed in exponential form.

[0114] The calculation formula is: Test item = (Example / Comparative Example 2-1) × 100.

[0115] Compared with Comparative Example 2-1, the Mooney viscosity of Comparative Examples 2-2 to 2-7 and Examples 2-1 to 2-3 increased to a certain extent, and the Mooney scorch time of Examples 2-1 to 2-3 became longer. As for MA100, Comparative Examples 2-2, 2-3, 2-6, 2-7 and Example 2-3 remained basically unchanged, while the others showed a decreasing trend. The tensile strength did not change much, and the elongation at break showed an increasing trend.

[0116] Compared with Comparative Example 2-1, the 100°C high-temperature slow tear energy of Comparative Examples 2-2 to 2-7 and Examples 2-1 to 2-3 were all improved, with Examples 2-1, 2-2, and 2-3 showing improvements of 25%, 134%, and 132%, respectively. The trend after aging was consistent with that before aging. Compared with Comparative Example 2-1, in terms of cutting loss, Comparative Examples 2-2 and 2-3 showed some improvement, but the magnitude was not large. Comparative Examples 2-4 and 2-5 showed improvements of 24% and 17%, respectively, while Comparative Examples 2-6 and 2-7 showed improvements of 9% and 17%, respectively. Examples 2-1, 2-2, and 2-3 showed improvements of 20%, 21%, and 20%, respectively. The trend after aging was almost consistent with that before aging.

[0117] Compared to Comparative Example 2-1, the hysteresis loss factors of Comparative Examples 2-2 and 2-3 decreased by 34% and 31%, respectively. The hysteresis loss factors of Comparative Examples 2-4, 2-5, 2-6, and 2-7 showed little change. The hysteresis loss factor of Example 2-1 decreased by 29%, while the hysteresis loss factors of Examples 2-2 and 2-3 decreased by 21% and 22%, respectively. Therefore, the combination of N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone, when used in tires, can both reduce heat generation and improve resistance to damage. The combination of N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone, and maleic anhydride monomethyl ester-modified liquid polyisoprene can significantly improve resistance to damage while ensuring reduced heat generation.

[0118] Example 3

[0119] The raw materials used in Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3 of this application are shown in Table 5 below, all in parts by mass. Examples 3-1 to 3-4 are rubber compositions using isophthalic acid dihydrazide, adipate dihydrazide, stearate dihydrazide, and 3-methyl-5-pyrazolone individually. Examples 3-5 to 3-7 are rubber compositions using a combination of 3-methyl-5-pyrazolone, isophthalic acid dihydrazide, adipate dihydrazide, stearate dihydrazide, and maleic anhydride monomethyl ester modified liquid polyisoprene.

[0120] Table 5: Formulations of Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3

[0121] The above schemes all adopt the following preparation method:

[0122] Step (1) Weigh the raw materials according to the above weight; Step (2) Mix natural rubber and BR9000 for 30 seconds, add hydrazide compounds and pyrazolone compounds, carbon black, and perform a mixing reaction at 140-160℃ for 150 seconds, then discharge the rubber at 160℃ to obtain material A; Step (3) Mix the remaining raw materials except for the 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 the 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 tires that reduces heat generation and improves resistance to damage. Then, vulcanize the rubber composition at 150℃ for 30 minutes for performance testing.

[0123] Performance tests were conducted on Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3, respectively, for unaged and aged at 100°C for 72 hours. The results are shown in Table 6 below.

[0124] Table 6: Comparison of performance results between Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3

[0125] *The test results for the rubber composition are expressed in exponential form.

[0126] The calculation formula is: Test item = (Example / Comparative Example 3-1) × 100.

[0127] Compared to Comparative Example 3-1, the Mooney viscosity of Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3 was significantly higher, the Mooney scorch time of Comparative Examples 3-2 to 3-4 was shorter, and the Mooney scorch time of Examples 3-1 to 3-3 was longer. The hardness and tensile strength of the comparative examples and examples did not change significantly. The elongation at break of Comparative Examples 3-2 to 3-4 did not change significantly, while the elongation at break of Examples 3-1 to 3-3 was greater.

[0128] Compared with Comparative Example 3-1, in terms of cutting loss, Comparative Examples 3-2 and 3-3 are worse, Comparative Example 3-4 shows little improvement, Comparative Example 3-5 shows an improvement of 10%, and Examples 3-1, 3-2, and 3-3 show significant improvements of 16%, 15%, and 19%, respectively, and the trend after aging is also the same.

[0129] Compared with Comparative Example 3-1, the hysteresis loss factors of Comparative Examples 3-2, 3-3, and 3-4 decreased by 21%, 17%, and 10%, respectively, while the hysteresis loss factor of Comparative Example 3-5 increased, resulting in higher heat generation. Compared with Comparative Example 3-1, the hysteresis loss factors of Examples 3-1, 3-2, and 3-3 decreased by 20%, 18%, and 16%, respectively.

[0130] Therefore, when isophthalic acid dihydrazide, adipate dihydrazide, and stearic acid dihydrazide are combined with liquid polyisoprene modified with 3-methyl-5-pyrazolone and maleic anhydride monomethyl ester, respectively, in tires, they can improve the resistance to damage and reduce the loss factor and heat generation.

[0131] 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 include the following parts by weight: 100 parts diene rubber, 0.2-1.5 parts acylhydrazine compounds, 0.2-1.5 parts pyrazolone compounds, 0-30 parts liquid rubber, 20-120 parts reinforcing filler, 0-10 parts silane coupling agent, and 2-10 parts vulcanization activator; wherein, The structure of the acylhydrazine compound is as follows: X 1 -CO-NH-NH2 (1) NH2-NH-CO-X 2 -CO-NH-NH2 (2) X 3 -CO-NH-N=X 4 (3) Where X 1 X 2 X 3 X 4 Independently selected from: aromatic hydrocarbon groups having 6 to 30 carbon atoms or alkane groups having 6 to 30 carbon atoms; wherein the aromatic hydrocarbon is optionally substituted with an alkyl, hydroxyl, or amino group having 1 to 20 carbon atoms; The structure of the pyrazolone compound is as follows: In this group, R1, R2, R3, and R4 each independently represent a hydrogen atom, alkyl, aralkyl, aryl, or heterocyclic group; R3 and R4 can be connected to form an alkylene group, and any two of R2, R3, and R4 can be connected 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, which are alkyl, aralkyl, aryl, or heterocyclic groups. 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 natural rubber and polyisoprene rubber, and 0-50 parts by weight of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber.

5. The rubber composition according to claim 1, characterized in that, The acylhydrazine compound is one or more of the following: adipate dihydrazine, isophthalic acid dihydrazine, terephthalic acid dihydrazine, caprylic acid dihydrazine, sebacic acid dihydrazine, dodecanoic acid dihydrazine, benzoic acid dihydrazine, naphthoic acid dihydrazine, propionic acid dihydrazine, caprylic acid dihydrazine, stearic acid dihydrazine, hexanoic acid dihydrazine, decanoic acid dihydrazine, oleic acid dihydrazine, lauroic acid dihydrazine, palmitic acid dihydrazine, N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthoic acid dihydrazine, 2-hydroxy-naphthoic acid dihydrazine, and 2-hydroxy-benzoic acid dihydrazine, and the proportion of the acylhydrazine compound in the rubber composition is 0.3-1.2 parts by weight.

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-(triethoxysilyl)propyl]-tetrasulfide, bis-[3-(triethoxysilyl)propyl]-disulfide, 3-octanoylthio-1-propyltriethoxysilane, γ-mercaptopropylethoxybis-(propane-hexaethoxysiloxane), mercaptoalkoxy-ethoxy, or methoxysilane, and the proportion of the silane coupling agent in the rubber composition is 0-8 parts by weight.

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, hydrazide compounds, pyrazolone compounds, liquid rubber, reinforcing filler, silane coupling agent, vulcanization accelerator, vulcanizing agent, antioxidant, vulcanization activator, resin and plasticizer; Step (2) Mix diene rubber, acyl hydrazine compound, pyrazolone compound 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 raw materials except for the vulcanizing agent and vulcanization accelerator 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) The vulcanizing agent and vulcanization accelerator are added to material B and then discharged after mixing to obtain the rubber composition.

10. A heavy-duty truck tire, characterized in that, Includes the rubber composition as described in any one of claims 1-8.

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