Rubber composition, preparation method thereof and truck tire using rubber composition

Abstract

The invention belongs to the technical field of rubber, and particularly relates to a rubber composition, a preparation method thereof and a truck tire using the rubber composition. The rubber composition is prepared from the following components in parts by mass: 100 parts of diene rubber, 0.2 to 1.5 parts of hydrazide compound, 0.2 to 1.5 parts of pyrazolone compound, 0 to 30 parts of liquid rubber, 20 to 120 parts of reinforcing filler, 0 to 10 parts of silane coupling agent, 2 to 10 parts of vulcanization activator, vulcanization accelerator, vulcanizing agent, antioxidant, resin and plasticizer. The heat generation of the tire can be obviously reduced, and meanwhile, the cutting resistance and tear resistance of the tire are improved, so that the damage resistance of the truck tire is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber, and in particular relates to a rubber composition and a preparation method thereof, and a load-carrying tire using the same. Background Art

[0002] During the driving process of engineering trucks, the rubber of the tires is exposed to heat, oxygen, fatigue and cutting damage under load and cyclic deformation. Reducing the heat generation of the tires and improving the cut and tear resistance of the tire rubber are the keys to improving the service life of the tires. However, using traditional methods, such as changing the type of rubber or increasing the amount of white carbon black used, to reduce the heat generation of the tires has many limitations in terms of overall performance balance. Since low heat generation requires the rubber material to have lower energy dissipation (hysteresis loss), while cut resistance and damage resistance under large deformation require higher energy dissipation capacity, low heat generation and high cut and tear resistance are contradictory. While reducing heat generation, cut and tear resistance often deteriorates, and often when improving one property, it is accompanied by the loss of other properties, which makes it difficult to improve the overall service life of the tire. In actual applications, increasing the amount of white carbon black or reducing the amount of filler in the rubber composition can reduce the heat generation of the tire, but the cut and tear resistance is reduced, resulting in delamination problems such as chipping, falling blocks or shoulder and rim voids, which affect the service life. Therefore, it is currently difficult to achieve both low heat generation and high cut and tear resistance at the same time.

[0003] To address this technical need, patent publication number CN112533991B discloses a rubber composition, a rubber material, and their uses, as well as additives represented by general formulas (2) and (3). The rubber composition exhibits low heat buildup, tear strength, and durability. However, tires made with this rubber composition exhibit weak resistance to damage, such as cut and tear resistance.

[0004] Patent publication number CN102257056A discloses a rubber composition, a rubber material comprising a combination of multiple diene rubbers, an inorganic filler exceeding 50%, additives, and methods for their use. While the use of a dihydrazide compound alone can significantly reduce the heat buildup of the rubber composition, there is no description or example data regarding cut and tear resistance. Therefore, given the conflicting nature of these two properties, the rubber composition fails to meet the requirements for both low tire heat buildup and improved cut and tear resistance.

[0005] Patent publication number CN103261300A discloses a rubber composition with a carbon black content greater than 50%. The composition is obtained by liquid-phase mixing of natural rubber and carbon black with the addition of a dihydrazide compound to achieve a highly dispersed, low-heating composition. However, the composition lacks description or examples of its cut and tear resistance. Therefore, given the conflicting nature of these two properties, the rubber composition fails to meet the requirements for both low heat generation and improved cut and tear resistance in tires.

[0006] Patent publication number CN111592695A discloses a rubber composition consisting of natural rubber with the addition of the low rolling resistance additive 1-naphthylacetylhydrazine, 0-40 parts of high-cis-butadiene rubber or solution-polymerized styrene butadiene, fillers, and additives. The composition is primarily intended to achieve low rolling resistance or low hysteresis without compromising wear performance, but lacks description or examples of cut and tear resistance. Therefore, given the conflicting nature of these two properties, the rubber composition fails to meet the tire's requirements for both low heat generation and improved cut and tear resistance.

[0007] Patent publication number CN113652012A discloses a rubber composition for tire base rubber that incorporates a carbon black dispersant, isophthalic acid hydrazide, and a large amount of thermally conductive fillers to reduce heat buildup and improve thermal conductivity. However, the composition lacks description or examples of its cut and tear resistance. Given the conflicting nature of these two properties, the composition fails to meet the requirements for both low heat buildup and improved cut and tear resistance.

[0008] Therefore, it is currently difficult to achieve both low heat buildup and high cut and tear resistance at the same time.

[0009] Therefore, how to provide a rubber composition and a preparation method thereof that can reduce heat generation and improve cut resistance and damage resistance is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0010] In view of this, the first object of the present invention is to provide a rubber composition that reduces heat generation and improves cut resistance and damage resistance in order to solve the problems existing in the prior art.

[0011] In order to achieve the above object, the present invention adopts the following technical solutions:

[0012] A rubber composition comprises the following raw materials in parts by mass: 100 parts of diene rubber, 0.2-1.5 parts of hydrazide 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,

[0013] The structure of the hydrazide compound is:

[0014] X 1 -CO-NH-NH2(1)

[0015] NH2-NH-CO-X 2 -CO-NH-NH2(2)

[0016] X 3 -CO-NH-N=X 4 (3)

[0017] where X 1 , X 2 , X 3 , X 4 Independently selected from: an aromatic hydrocarbon group having 6 to 30 carbon atoms or an alkane group having 6 to 30 carbon atoms; the aromatic hydrocarbon is arbitrarily substituted with an alkyl group having 1 to 20 carbon atoms, a hydroxyl group or an amino group;

[0018] The structure of the pyrazolone compound is:

[0019]

[0020] wherein R1, R2, R3, and R4 each independently represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; R3 and R4 may be linked to form an alkylene group, and any two of R2, R3, and R4 may be linked together to form an alkylene group; R5, R7, and R8 each independently represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; and R6 represents an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; and each of the groups independently may have one or more substituents, and the substituents are alkyl groups, aralkyl groups, aryl groups, or heterocyclic groups;

[0021] The structure of the liquid rubber is:

[0022]

[0023]

[0024] Wherein, l, m, and n are any integers from 1 to 1000.

[0025] In the present invention, the vulcanization activator is zinc oxide and stearic acid.

[0026] It is worth noting that hydrazide compounds can react with natural rubber to reduce heat generation. Pyrazolone compounds can be complexed with zinc oxide to form a weak sacrificial bond network, thereby improving the anti-damage performance of the rubber. The use of hydrazide compounds and pyrazolone compounds can not only reduce the heat generation of synthetic rubber but also improve the cut resistance of the rubber, and the two have a certain synergistic effect. While the liquid rubber containing special functional groups is added alone to improve the anti-damage effect, the hysteresis loss or heat generation is almost unchanged, and the anti-damage performance is greatly improved when added, and the heat generation is also reduced to a certain extent. The present invention can significantly reduce the heat generation of the tire while improving the cut resistance and tear resistance of the tire, thereby improving the anti-damage performance of the tire.

[0027] Furthermore, the rubber composition further comprises a vulcanization accelerator, a vulcanizing agent, an antioxidant, a vulcanization activator, a resin and a plasticizer.

[0028] In the present invention, the vulcanization accelerator is a combination of one or more of thiazoles, thiurams, sulfenamides, dithiocarbamates, xanthates, guanidines, and thioureas. Preferably, it is a combination of one or more of diphenylguanidine and N-cyclohexane-2-benzothiazolesulfenamide. The vulcanization accelerator accounts for 0.5-4 parts by mass, preferably 0.8-3 parts by mass, and more preferably 1-2.5 parts by mass in the rubber composition.

[0029] The vulcanizing agent is sulfur, and the proportion of the vulcanizing agent in the rubber composition is 0.5-5 parts by mass, preferably 0.8-3 parts by mass, and more preferably 1-2 parts by mass.

[0030] Furthermore, in the present invention, 6PPD is selected as an antioxidant. The rubber composition further comprises a protective agent, microcrystalline wax.

[0031] Furthermore, the diene rubber is a combination of one or more of modified or unmodified natural rubber, polyisoprene rubber, polybutadiene rubber, butadiene rubber, styrene-butadiene copolymer rubber, ethylene-propylene-diene monomer copolymer, styrene-isoprene-styrene ternary block copolymer rubber, and styrene-butadiene-styrene ternary block copolymer rubber.

[0032] Furthermore, the diene rubber is composed of 50-100 parts by mass of one or more of modified or unmodified natural rubber and polyisoprene rubber, and 0-50 parts by mass of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber.

[0033] Preferably, the diene rubber is composed of 60-100 parts by mass of a combination of one or more of modified or unmodified natural rubber and polyisoprene rubber, and 0-40 parts by mass of a combination of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber.

[0034] In the present invention, the styrene-butadiene copolymer rubber contains 5% to 40% by weight of styrene and is composed of one or more of the following elastomeric materials: 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 between -100 and 0°C, more preferably between -90 and -15°C, and even more preferably between -80 and -30°C.

[0035] It is worth noting that the use of the above-mentioned rubbers can simultaneously reduce tire heat generation and improve cut and tear resistance. Furthermore, among styrene-butadiene rubbers, emulsion-polymerized styrene-butadiene rubber is more preferred because of its high molecular weight and strong damage resistance. After modification with pyrazolone compounds, it achieves a better balance between cut resistance, heat generation, and processability. Among polybutadiene rubbers, those with nickel, lithium, or rare earth catalyst systems are even more preferred. The addition of modified polybutadiene rubber effectively balances wear resistance, rolling resistance, heat generation, processability, aging resistance, and fatigue crack growth performance.

[0036] Furthermore, the hydrazide compound is a combination of one or more of adipic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, suberic acid dihydrazide, sebacic acid dihydrazide, dodecanoic acid dihydrazide, benzoic acid hydrazide, naphthoic acid hydrazide, propionic acid hydrazide, octanoic acid hydrazide, stearic acid hydrazide, hexanoic acid hydrazide, capric acid hydrazide, oleic acid hydrazide, lauric acid hydrazide, palmitic acid hydrazide, N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 2-hydroxy-naphthoic acid hydrazide, and 2-hydroxy-benzoic acid hydrazide, and the proportion of the hydrazide compound in the rubber composition is 0.3-1.2 parts by mass.

[0037] In the present invention, the hydrazide compound is preferably a combination of one or more of adipic acid dihydrazide, isophthalic acid dihydrazide, and N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, and more preferably one or more of isophthalic acid dihydrazide and N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide. The proportion of the hydrazide compound in the rubber composition is preferably 0.3-1 parts by mass, and more preferably 0.3-0.8 parts by mass.

[0038] Furthermore, the pyrazolone compound is a combination of one or more 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.

[0039] In the present invention, 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 pyrazolone compound preferably accounts for 0.3-1 parts by mass, more preferably 0.3-0.8 parts by mass, in the rubber composition.

[0040] Furthermore, the liquid rubber is a combination of one or more of 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 500-100,000 g / mol, and the proportion of the liquid rubber in the rubber composition is 3-20 parts by mass.

[0041] In the present invention, the liquid rubber is preferably a combination of one or more of 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, and is further preferably a combination of one or more of 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 mass, more preferably 5-10 parts by mass.

[0042] It is worth noting that the present invention adopts the combination of the above-mentioned hydrazide compounds and pyrazolone compounds to graft-modify natural rubber, styrene-butadiene rubber, and butadiene rubber, and uses liquid rubber to produce a synergistic effect with hydrazide compounds and pyrazolone compounds, thereby reducing heat generation and improving anti-destructive properties such as cut resistance and tear resistance, thereby increasing the service life of the final product.

[0043] Furthermore, the reinforcing filler is a combination of one or more of modified or unmodified carbon black, acetylene black, white carbon black, carbon nanotubes, graphite, and graphene;

[0044] The silane coupling agent is a combination of one or more of bis-[3-(triethoxysilyl)propyl]-tetrasulfide, bis-[3-(triethoxysilyl)propyl]-disulfide, 3-octanoylthio-1-propyltriethoxysilane, γ-mercaptopropylethoxybis-(propyl-hexaethoxysiloxane), mercaptoalkoxy-ethoxy or methoxysilane, and the proportion of the silane coupling agent in the rubber composition is 0-8 parts by mass.

[0045] In the present invention, the preferred reinforcing filler is a combination of one or more of carbon black and white carbon black.

[0046] In some embodiments, the reinforcing filler consists of 0-50 parts by mass of white carbon black and 0-70 parts by mass of carbon black; preferably, consists of 0-40 parts by mass of white carbon black and 20-70 parts by mass of carbon black; more preferably, consists of 0-30 parts by mass of white carbon black and 30-60 parts by mass of carbon black.

[0047] And, the specific surface area of the carbon black is 20-160m 2 / g, the specific surface area of white carbon black is 60-250m 2 / g. More preferably, the specific surface area of the carbon black is 40-140m 2 / g, the specific surface area of white carbon black is 90-230m 2 / g.

[0048] In the present invention, 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 carbon black is 5-150 g / kg, and the DBP absorption value is 30-150 cm 3 / 100g.

[0049] In the present invention, the silane coupling agent is preferably a combination of one or more of bis-[3-(triethoxysilyl)propyl]tetrasulfide (Si69), bis-[3-(triethoxysilyl)propyl]disulfide (Si75), and 3-octanoylthio-1-propyltriethoxysilane (NXT), and more preferably a combination of one or more 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 mass, and more preferably 0-6 parts by mass.

[0050] It is worth noting that the present invention can better balance the heat generation and anti-destruction performance of the final product by adjusting the types and amounts of white carbon black, carbon black and silane coupling agent.

[0051] The second object of the present invention is to provide a method for preparing the rubber composition as described above.

[0052] A method for preparing the rubber composition as described above comprises the following steps:

[0053] Step (1) accurately weighing diene rubber, hydrazide compound, pyrazolone compound, liquid rubber, reinforcing filler, silane coupling agent, vulcanization accelerator, vulcanizing agent, antioxidant, vulcanization activator, resin and plasticizer;

[0054] Step (2) mixing the diene rubber, the hydrazide compound, the pyrazolone compound, and the reinforcing filler, and performing a mixing reaction at 120-180° C. for 60-300 seconds, and then cooling the mixture to obtain material A, wherein the discharge temperature is 120-180° C.;

[0055] Step (3) mixing the remaining raw materials except the vulcanizing agent and the vulcanization accelerator with material A, and performing a mixing reaction at 120-180° C. for 60-300 seconds, and then cooling to obtain material B, wherein the discharge temperature is 120-180° C.;

[0056] Step (4) adding a vulcanizing agent and a vulcanization accelerator to material B, mixing and discharging the mixture to obtain the rubber composition.

[0057] In the present invention, the hydrazide compound and the pyrazolone compound are all added in step (2), and the liquid rubber and the antioxidant can be partially or completely added in step (2), step (3) or step (4).

[0058] In some embodiments, part or all of the carbon black in the reinforcing filler may be added in step (2) or step (3); and the white carbon black and silane coupling agent in the reinforcing filler may be added in step (3).

[0059] In the present invention, the mixing reaction treatment at 120-180°C in step (2) is preferably carried out for 120-300 seconds, more preferably 150-300 seconds; the discharge temperature is 120-180°C, preferably 130-170°C, more preferably 140-160°C.

[0060] In the present invention, the mixing reaction treatment at 120-180°C in step (3) is preferably carried out for 120-300 seconds, more preferably 150-300 seconds; the discharge temperature is 120-180°C, preferably 130-170°C, more preferably 140-160°C.

[0061] It is worth noting that by adding a small amount of a hydrazide compound, a pyrazolone compound, and liquid rubber, and applying an optimized rubber mixing process consistent with the reaction between the hydrazide compound, the pyrazolone compound, and the rubber, the rubber composition can simultaneously reduce hysteresis loss and heat generation of the rubber, while also improving damage resistance such as cut and tear resistance. The preparation method of the present invention is simple to operate and highly practical.

[0062] A third object of the present invention is to provide a load-bearing tire comprising the rubber composition described above.

[0063] Compared with the prior art, the present invention reduces the hysteresis loss of the rubber material, reduces heat generation, and improves the cut and tear resistance, which is a balance that the traditional technology cannot achieve. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative work.

[0065] Figure 1 The invention provides a high-temperature slow tearing energy test specimen. DETAILED DESCRIPTION

[0066] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0067] The term "embodiment" is used herein specifically to describe any embodiment as "exemplary," and should not be construed as superior or preferable to other embodiments. Performance indicators in the embodiments of this application were tested using conventional testing methods in the art, unless otherwise specified. It should be understood that the terms used in this application are intended solely to describe specific implementations and are not intended to limit the disclosure herein.

[0068] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0069] In order to better illustrate the content of this application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that this application can be implemented without certain specific details. In the examples, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of this application.

[0070] Under the premise of no conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of this application.

[0071] The present invention provides a rubber composition, a preparation method thereof, and a load-bearing tire using the same. The rubber composition (by mass) includes 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 a 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 hydrazide compound can react with natural rubber to reduce heat generation, and the pyrazolone compound can complex with zinc oxide to form a weak sacrificial bond network, thereby improving the anti-destruction performance of the rubber. The liquid rubber containing special functional groups can be added alone to improve the anti-destruction effect, but the hysteresis loss or heat generation is almost unchanged, and when added together, the anti-destruction performance can be greatly improved and the heat generation is also reduced to a certain extent. The present invention can significantly reduce the heat generation of the tire while improving the cut and tear resistance of the tire, thereby improving the anti-destruction performance of the load-bearing tire.

[0072] In order to better understand the present invention, the present invention is further specifically described through the following examples, but it should not be understood as limiting the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above invention content are also considered to fall within the scope of protection of the present invention.

[0073] The standards and methods for testing the rubber composition of the present invention in the following examples are as follows:

[0074] 1) Mooney viscosity: Refer to ASTM D1646-2007, test conditions are ML (1+4) 100°C. The larger the index, the higher the Mooney viscosity.

[0075] 2) Mooney Scorch: Refer to ASTM D1646-2007, test temperature is 130°C. The larger the index, the longer the scorch time.

[0076] 3) Hardness: Shore hardness test, refer to ASTM D2240-2010. The larger the index, the higher the hardness.

[0077] 4) MA100: 100% tensile modulus test, referring to ASTM D412-2006, taking the modulus at 100% elongation, and the test environment temperature is 23±2°C. The larger the index, the higher the tensile modulus.

[0078] 5) Tensile strength and elongation at break: Refer to ASTM D412-2006, dumbbell-shaped specimens, test speed 500 mm / min, test ambient temperature 23 ± 2°C. A larger index indicates higher tensile strength.

[0079] 6) Hysteresis Loss Factor: Tested using Metravib DMA at 60°C, 10 Hz, dynamic deformation 0.07%-50%, in plane shear mode. A smaller index indicates lower hysteresis loss, and therefore lower rolling resistance and heat generation.

[0080] 7) High temperature slow tearing energy: Use a sample with a width of 40mm, a height of 65mm, and a notch of 10mm (see Figure 1 ), test speed 50mm / min, test environment temperature 100±5℃. The larger the index, the higher the high-temperature tear energy and the better the tear resistance.

[0081] 8) Dynamic cutting loss of rubber: Manufacturer: Beijing Wanhui Yifang, Test conditions: Strike frequency 120 / min; Rubber wheel speed 720 rpm; Test method: The mass of the rubber wheel 5 minutes after pre-cutting is recorded as m0, and the mass after 20 minutes of cutting is recorded as m1; Data is recorded as the cutting loss mass per minute: Δm = (m0-m1) / 15min; the smaller the index, the smaller the cutting mass loss and the better the cut and tear resistance.

[0082] The raw materials used in the embodiments of the present invention are as follows:

[0083] Natural rubber: STR20, Sinochem International Holdings Co., Ltd.

[0084] NS712 (Styrene-butadiene rubber) Japan ZSE Company

[0085] BR9000 (polybutadiene rubber) Sinopec Qilu Petrochemical Company

[0086] Hydrazide compounds: N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide, Otsuka Chemical Co., Ltd.

[0087] Hydrazide compounds: isophthalic acid dihydrazide, adipic acid dihydrazide, stearic acid hydrazide, TCI (Shanghai) Chemical Industry Development Co., Ltd.

[0088] Pyrazolone compounds: 3-Methyl-5-pyrazolone, Tokyo Chemical Industry Development Co., Ltd.

[0089] Liquid rubber: Liquid polyisoprene modified with monomethyl maleic anhydride, Kuraray Co., Ltd.

[0090] HD165MP, HD200MP (white carbon black) Wuxi Quecheng Silicon Co., Ltd.

[0091] N234, N220, N330, N115: Cabot Carbon Black

[0092] Si69, Si75: Nanjing Shuguang Chemical Group Co., Ltd.

[0093] NXT: Momentive

[0094] 6PPD (Antioxidant) Shandong Shangshun Chemical Co., Ltd.

[0095] Stearic acid: Sichuan Tianyu Oil Chemical Co., Ltd.

[0096] Zinc oxide: Dalian Zinc Oxide Co., Ltd.

[0097] Microcrystalline wax: Yanggu Huatai Chemical Co., Ltd.

[0098] NS(N-tert-butyl-2-benzothiazolesulfenamide)Shandong Shangshun Chemical Co., Ltd.

[0099] Sulfur: Shandong Shangshun Chemical Co., Ltd.

[0100] Example 1

[0101] The raw materials used in Examples 1-1 to 1-7 and Examples 1-1 to 1-3 of the present invention are shown in the following table, all expressed in parts by mass. Example 1-1 is a rubber composition using a combination of N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone. Examples 1-2 and 1-3 are rubber compositions using a combination of N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone, and liquid polyisoprene modified with monomethyl maleic anhydride.

[0102] Table 1: Formulas of Comparative Example 1-1 and Examples 1-1 to 1-9

[0103]

[0104] The above schemes all adopt the following preparation method:

[0105] The method comprises the following steps: (1) weighing the raw materials according to the above weight; (2) kneading the natural rubber for 30 seconds, adding a hydrazide compound and a pyrazolone compound, and carbon black, and performing a mixing reaction at 130-160° C. for 150 seconds, and performing a rubber discharge at 160° C. to obtain a material A; (3) kneading the remaining raw materials except the vulcanizing agent and the vulcanization accelerator with the material A, performing a mixing reaction at 140-160° C. for 150 seconds, and performing a rubber discharge at 160° C. to obtain a material B; and (4) adding the vulcanizing agent and the vulcanization accelerator to the material B, kneading the material in an internal mixer for about 180 seconds, and performing a rubber discharge at 110° C. to obtain a rubber composition for reducing heat generation and improving anti-damage performance of a tire. The rubber composition is then subjected to a vulcanization reaction at 150° C. for 30 minutes for performance testing.

[0106] For Comparative Examples 1-1 to 1-7 and Examples 1-1 to 1-3, performance tests were conducted before aging and after aging at 100° C. for 72 hours. The results are shown in Table 2 below.

[0107] Table 2: Comparison of performance results of Comparative Examples 1-1 to 1-7 and Examples 1-1 to 1-3

[0108]

[0109] *The test results of rubber compositions are expressed in the form of indices.

[0110] The calculation formula is: test item = (Example / Comparative Example 1-1) × 100.

[0111] Compared to Comparative Example 1-1, the Mooney viscosities of Comparative Examples 1-2 to 1-7 and Examples 1-1 to 1-3 increased to a certain extent, and the Mooney scorch times increased. MA100 increased for Comparative Examples 1-2 and 1-3, while decreased for Comparative Examples 1-4 and 1-5. The remaining MA100 values showed little change, including tensile strength and elongation at break. Compared to Comparative Example 1-1, the remaining 100°C high-temperature slow tear properties significantly improved, with Example 1-1 increasing by 245%, and Examples 1-2 and 1-3 increasing by 472% and 300%, respectively. The trends after aging were consistent with those before aging. Compared to Comparative Example 1-1, the hysteresis loss factors of Comparative Examples 1-2 and 1-3 decreased by 11% and 14%, respectively. The hysteresis loss factors 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%, while that of Examples 1-2 and 1-3 decreased by 13% and 14%, respectively. Therefore, the combination of N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone in tires can both reduce heat generation and improve damage resistance. The combination of N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone, and liquid polyisoprene modified with monomethyl maleic anhydride significantly improves damage resistance while ensuring reduced heat generation.

[0112] Example 2

[0113] The raw materials used in Comparative Examples 2-1 to 2-7 and Examples 2-1 to 2-3 of the present invention are shown in Table 3 below, all expressed in parts by mass. Example 2-1 is a rubber composition using a combination of N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone. Examples 2-2 and 2-3 are rubber compositions using a combination of N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone, and liquid polyisoprene modified with monomethyl maleic anhydride.

[0114] Table 3: Formulas of Comparative Examples 2-1 to 2-7 and Examples 2-1 to 2-3

[0115]

[0116] The above schemes all adopt the following preparation method:

[0117] The method comprises the following steps: (1) weighing raw materials according to the above weight; (2) mixing natural rubber and SBR1502 for 30 seconds, adding a hydrazide compound, a pyrazolone compound, and carbon black, and performing a mixing reaction at 140-160° C. for 150 seconds, and performing a rubber discharge at 160° C. to obtain material A; (3) mixing the remaining raw materials except the vulcanizing agent and the vulcanization accelerator with material A, performing a mixing reaction at 140-160° C. for 150 seconds, and performing a rubber discharge at 160° C. to obtain material B; and (4) adding the vulcanizing agent and the vulcanization accelerator to material B, mixing the material in an internal mixer for about 180 seconds, and discharging the material at 110° C. to obtain a rubber composition for reducing heat generation and improving damage resistance of tires. The rubber composition is then subjected to a vulcanization reaction at 150° C. for 30 minutes for performance testing.

[0118] The performance tests of Comparative Examples 2-1 to 2-7 and Examples 2-1 to 2-3 were conducted without aging and after aging at 100° C. for 72 hours, respectively. The results are shown in Table 4 below.

[0119] Table 4: Comparison of performance results of comparative examples 2-1 to 2-7 and examples 2-1 to 2-3

[0120]

[0121] *The test results of rubber compositions are expressed in the form of indices.

[0122] The calculation formula is: test item = (Example / Comparative Example 2-1) × 100.

[0123] Compared with Comparative Example 2-1, the Mooney viscosities of Comparative Examples 2-2 to 2-7 and Examples 2-1 to 2-3 increased to a certain extent, while the Mooney scorch times of Examples 2-1 to 2-3 increased. MA100 values remained essentially unchanged for Comparative Examples 2-2, 2-3, 2-6, and 2-7, as well as Example 2-3. The remaining values showed a decreasing trend, while tensile strength showed little change. Elongation at break showed an increasing trend.

[0124] Compared with Comparative Example 2-1, the 100°C high-temperature slow tearing 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 improving by 25%, 134%, and 132%, respectively. The trends after aging were consistent with those before aging. Compared with Comparative Example 2-1, the cutting loss of Comparative Examples 2-2 and 2-3 improved, but the magnitude was not significant. Comparative Examples 2-4 and 2-5 improved by 24% and 17%, respectively, while Comparative Examples 2-6 and 2-7 improved by 9% and 17%, respectively. Examples 2-1, 2-2, and 2-3 improved by 20%, 21%, and 20%, respectively. The trends after aging were almost consistent with those before aging.

[0125] 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 that of Examples 2-2 and 2-3 decreased by 21% and 22%. Therefore, the combination of N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone in tires can both reduce heat generation and improve damage resistance. The combination of N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone, and liquid polyisoprene modified with monomethyl maleic anhydride significantly improves damage resistance while ensuring reduced heat generation.

[0126] Example 3

[0127] The raw materials used in Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3 of the present invention are shown in Table 5 below, all expressed in parts by mass. Examples 3-1 to 3-4 are rubber compositions using isophthalic acid dihydrazide, adipic acid dihydrazide, stearic acid hydrazide, and 3-methyl-5-pyrazolone alone, while Examples 3-5 to 3-7 are rubber compositions using a combination of 3-methyl-5-pyrazolone, isophthalic acid dihydrazide, adipic acid dihydrazide, stearic acid hydrazide, and liquid polyisoprene modified with monomethyl maleic anhydride.

[0128] Table 5: Formulas of Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3

[0129]

[0130] The above schemes all adopt the following preparation method:

[0131] The method comprises the following steps: (1) weighing raw materials according to the above weight; (2) mixing natural rubber and BR9000 for 30 seconds, adding a hydrazide compound, a pyrazolone compound, and carbon black, and performing a mixing reaction at 140-160° C. for 150 seconds, and performing a debonding at 160° C. to obtain material A; (3) mixing the remaining raw materials except the vulcanizing agent and the vulcanization accelerator with material A, performing a mixing reaction at 140-160° C. for 150 seconds, and performing a debonding at 160° C. to obtain material B; and (4) adding the vulcanizing agent and the vulcanization accelerator to material B, mixing the material in an internal mixer for about 180 seconds, and performing a debonding at 110° C. to obtain a rubber composition for reducing heat generation and improving damage resistance of tires. The rubber composition is then vulcanized at 150° C. for 30 minutes for performance testing.

[0132] For Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3, performance tests were conducted before aging and after aging at 100° C. for 72 hours. The results are shown in Table 6 below.

[0133] Table 6: Comparison of performance results of comparative examples 3-1 to 3-5 and examples 3-1 to 3-3

[0134]

[0135] *The test results of rubber compositions are expressed in the form of indices.

[0136] The calculation formula is: test item = (Example / Comparative Example 3-1) × 100.

[0137] Compared with Comparative Example 3-1, the Mooney viscosities of Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3 were significantly higher. The Mooney scorch times of Comparative Examples 3-2 to 3-4 were shortened, while those of Examples 3-1 to 3-3 were prolonged. The hardness and tensile strength of the Comparative Examples and Examples showed little change. The elongation at break of Comparative Examples 3-2 to 3-4 showed little change, while that of Examples 3-1 to 3-3 was increased.

[0138] Compared with comparative example 3-1, in terms of cutting loss, comparative examples 3-2 and 3-3 deteriorated, comparative example 3-4 showed little improvement, comparative example 3-5 improved by 10%, and embodiments 3-1, 3-2, and 3-3 improved by 16%, 15%, and 19%, respectively, with significant improvements, and the same trend was observed after aging.

[0139] Compared to Comparative Example 3-1, the hysteresis loss factors of Comparative Examples 3-2, 3-3, and 3-4 were reduced by 21%, 17%, and 10%, respectively. Comparative Example 3-5 exhibited an increased hysteresis loss factor and higher heat generation. Compared to Comparative Example 3-1, the hysteresis loss factors of Examples 3-1, 3-2, and 3-3 were reduced by 20%, 18%, and 16%, respectively.

[0140] Therefore, when isophthalic acid dihydrazide, adipic acid dihydrazide, and stearic acid hydrazide are respectively combined with liquid polyisoprene modified with 3-methyl-5-pyrazolone and maleic anhydride monomethyl ester and used in tires, the anti-damage performance can be improved while reducing the loss factor and heat generation.

[0141] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A rubber composition, characterized in that The invention comprises the following raw materials in parts by weight: 100 parts of diene rubber, 0.2-1.5 parts of hydrazide 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, The structure of the hydrazide 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) where X 1 , X 2 , X 3 , X 4 Independently selected from: an aromatic hydrocarbon group having 6 to 30 carbon atoms or an alkane group having 6 to 30 carbon atoms; the aromatic hydrocarbon is arbitrarily substituted with an alkyl group having 1 to 20 carbon atoms, a hydroxyl group or an amino group; The structure of the pyrazolone compound is: wherein R1, R2, R3, and R4 each independently represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; R3 and R4 may be linked to form an alkylene group, and any two of R2, R3, and R4 may be linked together to form an alkylene group; R5, R7, and R8 each independently represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; and R6 represents an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; and each of the groups independently may have one or more substituents, and the substituents are alkyl groups, aralkyl groups, aryl groups, or heterocyclic groups; The structure of the liquid rubber is: Wherein, l, m, and n are any integers from 1 to 1000.

2. The rubber composition according to claim 1, wherein Also included are vulcanization accelerators, vulcanizing agents, antioxidants, resins, and plasticizers.

3. The rubber composition according to claim 1, characterized in that The diene rubber is a combination of one or more of modified or unmodified natural rubber, polyisoprene rubber, polybutadiene rubber, 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 mass of one or more of modified or unmodified natural rubber and polyisoprene rubber, and 0-50 parts by mass of one or more of modified or unmodified styrene-butadiene copolymer rubber and polybutadiene rubber.

5. The rubber composition according to claim 1, wherein The hydrazide compound is a combination of one or more of adipic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, suberic acid dihydrazide, sebacic acid dihydrazide, dodecanoic acid dihydrazide, benzoic acid hydrazide, naphthoic acid hydrazide, propionic acid hydrazide, octanoic acid hydrazide, stearic acid hydrazide, hexanoic acid hydrazide, capric acid hydrazide, oleic acid hydrazide, lauric acid hydrazide, palmitic acid hydrazide, N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 2-hydroxy-naphthoic acid hydrazide, and 2-hydroxy-benzoic acid hydrazide, and the proportion of the hydrazide compound in the rubber composition is 0.3-1.2 parts by mass.

6. The rubber composition according to claim 1, wherein The pyrazolone compound is a combination of one or more 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.

7. The rubber composition according to claim 1, wherein The liquid rubber is a combination of one or more of 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 500-100,000 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, wherein The reinforcing filler is a combination of one or more of modified or unmodified carbon black, acetylene black, white carbon black, carbon nanotubes, graphite, and graphene; The silane coupling agent is a combination of one or more of bis-[3-(triethoxysilyl)propyl]-tetrasulfide, bis-[3-(triethoxysilyl)propyl]-disulfide, 3-octanoylthio-1-propyltriethoxysilane, γ-mercaptopropylethoxybis-(propyl-hexaethoxysiloxane), mercaptoalkoxy-ethoxy or methoxysilane, and the proportion of the silane coupling agent in the rubber composition is 0-8 parts by mass.

9. The method for preparing the rubber composition according to any one of claims 1 to 8, wherein: The following steps are involved: Step (1) accurately weighing diene rubber, hydrazide compound, pyrazolone compound, liquid rubber, reinforcing filler, silane coupling agent, vulcanization accelerator, vulcanizing agent, antioxidant, vulcanization activator, resin and plasticizer; Step (2) mixing the diene rubber, the hydrazide compound, the pyrazolone compound, and the reinforcing filler, and performing a mixing reaction at 120-180° C. for 60-300 seconds, and then cooling the mixture to obtain material A, wherein the discharge temperature is 120-180° C.; Step (3) mixing the remaining raw materials except the vulcanizing agent and the vulcanization accelerator with material A, and performing a mixing reaction at 120-180° C. for 60-300 seconds, and then cooling to obtain material B, wherein the discharge temperature is 120-180° C.; Step (4) adding a vulcanizing agent and a vulcanization accelerator to material B, mixing and discharging the mixture to obtain the rubber composition.

10. A load-carrying tire, characterized in that: The rubber composition comprises the rubber composition according to any one of claims 1 to 8.

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