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 in an environment of 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, there are many limitations in the overall performance balance. Since low heat generation requires the rubber material to have lower energy dissipation (hysteresis loss), and the 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, the cut and tear resistance often deteriorates, and often when improving one performance, it is accompanied by the loss of other performances, which makes it difficult to improve the overall service life of the tire. In practical 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 decreases, resulting in delamination problems such as broken flowers, blocks, shoulders, and rims, 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] In response to this technical demand, patent document CN112533991B discloses a rubber composition, a rubber material and their uses, and additives represented by general formulas (2) and (3), which is a rubber composition capable of exhibiting low heat generation, tear strength and durability. Similarly, the tire made of the rubber composition has weak anti-destructive properties such as cut resistance and tear resistance.

[0004] The patent document with patent publication number CN102257056A discloses a rubber composition, a rubber material containing multiple diene rubbers, an inorganic filler greater than 50%, an additive and a method of using the same. The use of a dihydrazide compound alone can significantly reduce the heat generation of the rubber composition, but there is no description or example data description of the cut and tear resistance. Therefore, in view of the contradiction between low heat generation and cut and tear resistance, the rubber composition cannot meet the requirements of low heat generation of tires and improved cut and tear resistance at the same time.

[0005] The patent document with patent publication number CN103261300A discloses a rubber composition with a carbon black content greater than 50%, which is a highly dispersed low heat generation composition obtained by mixing natural rubber and carbon black by a liquid phase method and adding a dihydrazide compound, but there is no description and example data description of the cut and tear resistance. Therefore, in view of the contradiction between low heat generation and cut and tear resistance, the rubber composition cannot meet the requirements of low heat generation of tires and improve cut and tear resistance at the same time.

[0006] The patent document with the patent publication number CN111592695A discloses a rubber composition composed of natural rubber with low rolling resistance additive 1-naphthylacetylhydrazine and high cis-butadiene rubber or 0-40 parts of solution-polymerized butadiene styrene, fillers, additives, etc., mainly for the purpose of obtaining low rolling resistance or low hysteresis without affecting the wear performance, but there is no description and example data description for the cut and tear resistance performance. Therefore, in view of the contradiction between low heat generation and cut and tear resistance performance, the rubber composition cannot meet the use requirements of low heat generation of tires and improve cut and tear resistance at the same time.

[0007] The patent document with patent publication number CN113652012A discloses a rubber composition of tire base rubber with carbon black dispersant isophthalic acid hydrazide and a large amount of thermal conductive filler added to reduce heat generation and improve thermal conductivity, but there is no description and example data description of the cut and tear resistance. Therefore, in view of the contradiction between low heat generation and cut and tear resistance, the rubber composition cannot meet the use requirements of low heat generation of tires and improved cut and tear resistance at the same time.

[0008] Therefore, it is currently difficult to achieve both low heat generation and high cut and tear resistance.

[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 need to solve urgently. 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 solution:

[0012] A rubber composition comprises the following raw materials in parts by weight: 100 parts of diene rubber, 0.2-1.5 parts of hydrazide compounds, 0.2-1.5 parts of pyrazolone compounds, 0-30 parts of liquid rubber, 20-120 parts of reinforcing fillers, 0-10 parts of silane coupling agents, and 2-10 parts of vulcanization activators; 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 by 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 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, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; R6 represents an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; and the groups each 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 the effect of heat generation. Pyrazolone compounds can be complexed with zinc oxide to form a weak sacrificial bond network, thereby improving the anti-damage performance of 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. The addition of liquid rubber containing special functional groups alone has the effect of improving the anti-damage, but the hysteresis loss or heat generation is almost unchanged, and the anti-damage performance will be greatly improved when added, and the heat generation will be 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 also includes 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-benzothiazole sulfenamide. The proportion of the vulcanization accelerator in the rubber composition is 0.5-4 parts by mass, preferably 0.8-3 parts by mass, and more preferably 1-2.5 parts by mass.

[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 also includes 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%-40%wt of styrene, and the styrene-butadiene copolymer rubber is a combination of one or more of the following elastomeric 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.

[0035] It is worth noting that the use of the above rubber can reduce tire heat generation and improve cut and tear resistance. In addition, the more preferred styrene butadiene rubber is emulsion polystyrene butadiene rubber, because the emulsion polystyrene butadiene rubber has a high molecular weight and strong anti-destruction ability. After adding pyrazolone compounds for modification, the balance of cut resistance, heat generation and processing performance is better. Among polybutadiene rubbers, nickel catalyst system, lithium catalyst system and rare earth catalyst system are more preferred. The addition of modified polybutadiene rubber can effectively balance wear resistance, rolling resistance heat generation, processing performance and aging resistance and fatigue crack growth performance.

[0036] Further, 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, caprylic acid hydrazide, stearic acid hydrazide, caproic 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. And, the proportion 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 pyrazolone compound accounts for 0.3-1.2 parts by weight in the rubber composition.

[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, and more preferably 3-methyl-5-pyrazolone. The proportion of the pyrazolone compound in the rubber composition is preferably 0.3-1 parts by mass, and more preferably 0.3-0.8 parts by mass.

[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 500-100000 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, and carboxylic acid acrylate-modified liquid polybutadiene, and is further preferably a combination of one or more of maleic anhydride-modified liquid polyisoprene and carboxylic acid acrylate-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 and 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-destruction properties such as cut resistance and tear resistance, thereby increasing the service life of the final product.

[0043] Further, 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 and 0-70 parts by mass of carbon black; preferably, consists of 0-40 parts by mass of white carbon and 20-70 parts by mass of carbon black; more preferably, consists of 0-30 parts by mass of white carbon 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 is 60-250m 2 More preferably, the specific surface area of ​​the carbon black is 40-140m 2 / g, the specific surface area of ​​white carbon 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 above carbon black is 5-150g / kg, and the DBP absorption value is 30-150cm 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 (Si 69), 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). And 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-damage performance of the final product through 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, hydrazide compound, pyrazolone compound and reinforcing filler and subjecting the mixture to a mixing reaction treatment at 120-180° C. for 60-300 seconds, and 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 cooling the mixture 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) or step (3) or step (4).

[0058] In some embodiments, the carbon black in the reinforcing filler may be partially or completely added in step (2) or step (3); the white carbon black and the silane coupling agent in the reinforcing filler are all 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 hydrazide compounds, pyrazolone compounds, and liquid rubber, and applying an optimized rubber refining process that conforms to the reaction of hydrazide compounds, pyrazolone compounds, and rubber, the rubber composition can simultaneously reduce the hysteresis loss of the rubber, reduce heat generation, and simultaneously improve the anti-destructive properties such as cutting and tearing resistance. The preparation method of the present invention is simple to operate and has strong practicality.

[0062] A third object of the present invention is to provide a load-carrying 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 cutting and tearing 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For ordinary technicians in this field, 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 technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0068] Unless otherwise specified, the technical and scientific terms used in this document 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 the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, 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 the present application.

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

[0071] The present invention provides a rubber composition and 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 hydrazide compounds, 0.2-1.5 parts of pyrazolone compounds, 0-30 parts of liquid rubber, 20-120 parts of reinforcing fillers, 0-10 parts of silane coupling agents, 2-10 parts of vulcanization activators, vulcanization accelerators, vulcanizing agents, antioxidants, resins and plasticizers. Hydrazide compounds can react with natural rubber to reduce the effect of heat generation, and pyrazolone compounds can be complexed with zinc oxide to form a weak sacrificial bond network to improve the anti-destruction performance of rubber. Liquid rubber containing special functional groups is added alone to improve the anti-destruction effect, but the hysteresis loss or heat generation is almost unchanged, and when added, the anti-destruction performance will be greatly improved and the heat generation will be 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-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 technicians in this field based on the above invention content are also considered to fall within the protection scope 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, the test condition is ML (1+4) 100°C. The larger the index, the higher the Mooney viscosity.

[0075] 2) Mooney scorch: Refer to ASTM D1646-2007, the 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, refer to ASTM D412-2006, take the modulus when the elongation is 100%, 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, the sample is dumbbell-shaped, the test speed is 500mm / min, and the test environment temperature is 23±2°C. The larger the index, the higher the tensile strength.

[0079] 6) Hysteresis loss factor: Tested using Metravib DMA, temperature 60°C, frequency 10 Hz, dynamic deformation 0.07%-50%, plane shear mode. The smaller the index, the smaller the hysteresis loss, the lower the rolling resistance and heat generation.

[0080] 7) High temperature slow tearing energy: Use a sample with a width of 40 mm, a height of 65 mm, and a notch of 10 mm (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: striking frequency 120 / min; rubber wheel speed 720rpm; Test method: the mass of the rubber wheel after 5 minutes of pre-cutting is recorded as m0, and the mass after 20 minutes of cutting is m1; data records the cutting loss mass per minute: Δm=(m0-m1) / 15min; the smaller the index, the smaller the cutting mass loss, and the better the cutting and tearing 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-dimethylbutylene)-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, TCI (Shanghai) Chemical Industry Development Co., Ltd.

[0089] Liquid rubber: Carboxylic acid acrylate modified liquid polyisoprene, 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 the ratios 1-1 to 1-7 of the present invention and the examples 1-1 to 1-3 are shown in the following table, all in mass fractions. Among them, the example 1-1 is a rubber composition using N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone in combination. The examples 1-2 and 1-3 are rubber compositions using N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone and carboxylic acid acrylate modified liquid polyisoprene in combination.

[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] Step (1) weighing the raw materials according to the above weight; step (2) mixing the natural rubber for 30 seconds, adding hydrazide compounds and pyrazolone compounds, carbon black, mixing and reacting at 130-160°C for 150 seconds, and discharging at 160°C to obtain material A; step (3) mixing the remaining raw materials except the vulcanizing agent and the vulcanization accelerator with material A, mixing and reacting at 140-160°C for 150 seconds, and discharging at 160°C to obtain material B; step (4) adding the vulcanizing agent and the vulcanization accelerator to material B, mixing in an internal mixer for about 180 seconds, and discharging at 110°C to obtain a rubber composition for reducing heat generation and improving anti-damage performance of tires. Then the rubber composition is vulcanized at 150°C for 30 minutes for performance testing.

[0106] For comparative examples 1-1 to 1-7 and embodiments 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 embodiments 1-1 to 1-3

[0108]

[0109]

[0110] *The test results of rubber compositions are expressed in the form of indices.

[0111] The calculation formula is: test item=(embodiment / comparative example 1-1)×100.

[0112] Compared with Comparative Example 1-1, the Mooney viscosity of Comparative Examples 1-2 to 1-7 and Examples 1-1 to 1-3 has increased to a certain extent, and the Mooney scorch time has increased. In terms of MA100, Comparative Examples 1-2 and 1-3 have increased, while Comparative Examples 1-4 and 1-5 have decreased. The rest have not changed much, and the tensile strength and elongation at break have not changed much. Compared with Comparative Example 1-1, the rest of the 100°C high-temperature slow tearing energy has been greatly improved, among which Example 1-1 has increased by 245%, and Examples 1-2 and 1-3 have increased by 472% and 300% respectively. The trend after aging is consistent with that before aging. Compared with Comparative Example 1-1, the hysteresis loss factors of Comparative Examples 1-2 and 1-3 have decreased by 11% and 14% respectively, and the hysteresis loss factors of Comparative Examples 1-4, 1-5, 1-6 and 1-7 have not changed much, the hysteresis loss factor of Example 1-1 has decreased by 11%, and the hysteresis loss factors of Examples 1-2 and 1-3 have decreased by 13% and 14%. Therefore, when N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone are used in tires, heat generation can be reduced and damage resistance can be improved. When N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone and carboxylic acid acrylate modified liquid polyisoprene are combined, damage resistance can be greatly improved and heat generation can be reduced.

[0113] Example 2

[0114] 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 in mass fractions. Among them, Example 2-1 is a rubber composition using N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone in combination. Examples 2-2 and 2-3 are rubber compositions using N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone and carboxylic acid acrylate modified liquid polyisoprene in combination.

[0115] Table 3: Formulas of Comparative Examples 2-1 to 2-7 and Examples 2-1 to 2-3

[0116]

[0117] The above schemes all adopt the following preparation method:

[0118] Step (1) weighing the raw materials according to the above weight; step (2) mixing natural rubber and SBR1502 for 30 seconds, adding hydrazide compounds and pyrazolone compounds, carbon black, mixing and reacting at 140-160°C for 150 seconds, and discharging at 160°C to obtain material A; step (3) mixing the remaining raw materials except the vulcanizing agent and the vulcanization accelerator with material A, mixing and reacting at 140-160°C for 150 seconds, and discharging at 160°C to obtain material B; step (4) adding the vulcanizing agent and the vulcanization accelerator to material B, mixing in an internal mixer for about 180 seconds, and discharging at 110°C to obtain a rubber composition for reducing heat generation and improving damage resistance of tires. Then the rubber composition is vulcanized at 150°C for 30 minutes for performance testing.

[0119] The performance tests of Comparative Examples 2-1 to 2-7 and Examples 2-1 to 2-3 were respectively carried out without aging and after aging at 100° C. for 72 hours. The results are shown in Table 4 below.

[0120] Table 4: Comparison of performance results of comparative examples 2-1 to 2-7 and examples 2-1 to 2-3

[0121]

[0122] *The test results of rubber compositions are expressed in the form of indices.

[0123] The calculation formula is: test item = (Example / Comparative Example 2-1) × 100.

[0124] 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, and the Mooney scorch time of Examples 2-1 to 2-3 became longer. In terms of 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.

[0125] 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 are all improved, among which examples 2-1, 2-2, and 2-3 are improved by 25%, 134%, and 132%, respectively. The trend after aging is consistent with that before aging. Compared with comparative example 2-1, in terms of cutting loss, comparative examples 2-2 and 2-3 have improved, but the magnitude is not large. Comparative examples 2-4 and 2-5 have improved by 24% and 17%, respectively, comparative examples 2-6 and 2-7 have improved by 9% and 17%, respectively, and examples 2-1, 2-2, and 2-3 have improved by 20%, 21%, and 20%, respectively. The trend after aging is almost the same as that before aging.

[0126] Compared with comparative example 2-1, the hysteresis loss factors of comparative examples 2-2 and 2-3 are reduced by 34% and 31% respectively, and the hysteresis loss factors of comparative examples 2-4, 2-5, 2-6, and 2-7 do not change much. The hysteresis loss factor of embodiment 2-1 is reduced by 29%, and the hysteresis loss factors of embodiments 2-2 and 2-3 are reduced by 21% and 22%. Therefore, when N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide and 3-methyl-5-pyrazolone are used in tires, heat generation can be reduced and anti-destruction performance can be improved. When N'-(1,3-dimethylbutylene)-3-hydroxy-2-naphthohydrazide, 3-methyl-5-pyrazolone and carboxylic acid acrylate modified liquid polyisoprene are combined, anti-destruction performance can be greatly improved and heat generation can be reduced.

[0127] Example 3

[0128] 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 in mass fractions. Among them, 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, and Examples 3-5 to 3-7 are rubber compositions using 3-methyl-5-pyrazolone, isophthalic acid dihydrazide, adipic acid dihydrazide, stearic acid hydrazide, and carboxylic acid acrylate modified liquid polyisoprene in combination.

[0129] Table 5: Formulas of Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3

[0130]

[0131] The above schemes all adopt the following preparation method:

[0132] Step (1) weighing the raw materials according to the above weight; step (2) mixing natural rubber and BR9000 for 30 seconds, adding hydrazide compounds and pyrazolone compounds, and carbon black, mixing and reacting at 140-160° C. for 150 seconds, and debonding at 160° C. to obtain material A; step (3) mixing the remaining raw materials except the vulcanizing agent and the vulcanization accelerator with material A, and heating at 140-160° C. The mixing reaction treatment time is 150 seconds, and the material B is obtained by debonding at 160°C; step (4) vulcanizing agent and vulcanization accelerator The mixture was added to material B and mixed in an internal mixer for about 180 seconds, and discharged at 110° C. to obtain a rubber composition for reducing heat generation and improving damage resistance for tires. The rubber composition was then vulcanized at 150° C. for 30 minutes for performance testing.

[0133] For comparative examples 3-1 to 3-5 and embodiments 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.

[0134] Table 6: Comparison of performance results of comparative examples 3-1 to 3-5 and examples 3-1 to 3-3

[0135]

[0136] *The test results of rubber compositions are expressed in the form of indices.

[0137] The calculation formula is: test item = (Example / Comparative Example 3-1) × 100.

[0138] Compared with Comparative Example 3-1, the Mooney viscosity of Comparative Examples 3-1 to 3-5 and Examples 3-1 to 3-3 also significantly increased, the Mooney scorch time of Comparative Examples 3-2 to 3-4 was shortened, and the Mooney scorch time of Examples 3-1 to 3-3 was prolonged. The hardness and tensile strength of the Comparative Examples and Examples did not change much. The elongation at break of Comparative Examples 3-2 to 3-4 did not change much, and the elongation at break of Examples 3-1 to 3-3 increased.

[0139] Compared with comparative example 3-1, in terms of cutting loss, comparative examples 3-2 and 3-3 deteriorate, comparative example 3-4 improves slightly, comparative example 3-5 improves by 10%, and embodiments 3-1, 3-2, and 3-3 improve by 16%, 15%, and 19%, respectively, with significant improvements, and the same trend is observed after aging.

[0140] Compared with 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, and the hysteresis loss factor of Comparative Example 3-5 was increased, and the heat generation was increased. Compared with 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.

[0141] Therefore, when isophthalic acid dihydrazide, adipic acid dihydrazide, and stearic acid hydrazide are respectively combined with 3-methyl-5-pyrazolone and carboxylic acid acrylate modified liquid polyisoprene and used in tires, the anti-damage performance can be improved and the loss factor and heat generation can be reduced.

[0142] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 will not be limited to the embodiments shown herein, but rather 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 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 by 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 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, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; R6 represents an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; and the groups each 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, 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 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 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 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, caprylic acid hydrazide, stearic acid hydrazide, caproic 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, characterized in that 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, characterized in that 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 500-100000 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 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, characterized in that: 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, hydrazide compound, pyrazolone compound and reinforcing filler and subjecting the mixture to a mixing reaction treatment at 120-180° C. for 60-300 seconds, and 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 cooling the mixture 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 as claimed in any one of claims 1 to 8.

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