Anti-aging agent composition, rubber composition and application thereof

Abstract

The invention provides an anti-aging agent composition, a rubber composition containing the anti-aging agent composition and application of the rubber composition. The rubber composition provided by the invention comprises an anti-aging agent 6PPD, an anti-aging agent TMQ and an anti-aging agent A. The rubber composition disclosed by the invention has relatively good reversion resistance, thermo-oxidative aging resistance and damp-heat aging resistance as well as excellent bonding performance, and is particularly suitable for being applied to a tire body or a belted layer.

Description

Technical Field

[0001] The invention belongs to the field of rubber materials and relates to an antioxidant composition, a rubber composition and uses thereof. Background Art

[0002] Tires are an important component of modern cars. They are often used at high speeds and high loads, and are subject to impacts and bumps caused by uneven roads, as well as adverse factors such as high temperature, salty or corrosive water. The quality of their performance directly affects the economy of car use and driving safety.

[0003] The tire belt and carcass are two important parts of the tire, both of which are required to have excellent adhesion and heat resistance.

[0004] (1) The belt layer is composed of a rubber composition and a metal skeleton material. During the driving process of the car, the belt layer of the tire will be subjected to a large shear stress, so the belt layer rubber is required to have high tensile strength and fatigue resistance. At the same time, because the belt layer is located in the middle of the tire body, heat is not easy to dissipate, and the belt layer rubber composition must have excellent resistance to thermal oxidation aging. In addition, since rubber and steel cord have great differences in modulus, polarity, etc., the belt layer rubber composition must also have excellent adhesion to the metal surface.

[0005] (2) The tire body is composed of a rubber composition and a skeleton material. When the car is running, the tire body is subjected to tension caused by high loads. Therefore, in addition to having high tensile strength, the tire body rubber must also have excellent adhesion to metal or fiber skeleton materials to ensure its high load and durability. At the same time, the tire will heat up during driving, causing the temperature of various components to rise, so the tire body rubber composition should also have good resistance to thermal oxidation aging.

[0006] Vulcanization reversion refers to the phenomenon that during the rubber vulcanization process, the cross-linked network of the vulcanized rubber produced due to high vulcanization temperature and long vulcanization time is cracked, and the performance of the vulcanized rubber is reduced.

[0007] Tire rubber compositions, especially belt and carcass rubber compositions, often use p-phenylenediamine antioxidants, such as N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine (6PPD), N,N'-dimethylphenylenediamine (DTPD), etc. The p-phenylenediamine antioxidants currently used in the steel wire rubber compositions of tire carcasses and belts have good effects on the ozone resistance and long-term effectiveness of the rubber composition, but perform poorly in terms of anti-vulcanization reversion and adhesion performance. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides an antioxidant composition capable of providing excellent anti-reversion performance, anti-thermal aging performance, anti-wet-heat aging performance and / or adhesion performance with metal, a rubber composition containing the antioxidant composition and its use. The rubber composition of the present invention can have good anti-reversion performance, anti-thermal aging performance and anti-wet-heat aging performance, as well as excellent adhesion performance, and is particularly suitable for application in tire carcasses or belt layers.

[0009] Specifically, one aspect of the present invention provides an antioxidant composition, which comprises antioxidant 6PPD, antioxidant TMQ and antioxidant A shown in formula I:

[0010]

[0011] In one or more embodiments, in the antioxidant composition, the mass ratio of antioxidant 6PPD to antioxidant A is 8:1 to 1:4, preferably 3:1 to 1:3.

[0012] In one or more embodiments, in the antioxidant composition, the ratio of the total mass of antioxidant 6PPD and antioxidant A to the mass of antioxidant TMQ is 1:1 to 3:1, preferably 1.8:1 to 2.2:1.

[0013] Another aspect of the present invention provides a rubber composition, wherein the raw materials of the rubber composition include 100 parts by mass of a diene elastomer and 0.5-5 parts by mass of the antioxidant composition described in any embodiment of the present invention.

[0014] In one or more embodiments, the antioxidant composition is used in an amount of 2-4 parts by mass, preferably 2.5-3.5 parts by mass, in the raw materials of the rubber composition.

[0015] In one or more embodiments, the diene elastomer is natural rubber.

[0016] In one or more embodiments, the raw materials of the rubber composition further include 30-70 parts by mass of a reinforcing filler; the reinforcing filler preferably comprises carbon black.

[0017] In one or more embodiments, the raw material of the rubber composition further comprises 2-15 parts by mass of an active agent; the active agent preferably comprises zinc oxide.

[0018] In one or more embodiments, the raw material of the rubber composition further includes 0.1-2 parts by mass of a cobalt salt; the cobalt salt preferably includes cobalt decanoate.

[0019] In one or more embodiments, the raw materials of the rubber composition further include 1-10 parts by mass of a rubber binder; the rubber binder preferably includes a resorcinol donor and a methylene donor.

[0020] In one or more embodiments, the raw materials of the rubber composition further include 2-8 parts by mass of sulfur.

[0021] In one or more embodiments, the raw material of the rubber composition further includes 0.5-5 parts by mass of an accelerator; the accelerator preferably comprises N,N'-dicyclohexyl-2-benzothiazolesulfenamide.

[0022] Another aspect of the present invention provides a rubber product, wherein the rubber product comprises the rubber composition described in any embodiment of the present invention.

[0023] In one or more embodiments, the rubber composition is a tire band or a tire carcass.

[0024] The present invention also provides the use of the antioxidant composition described in any embodiment of the present invention in improving the anti-vulcanization reversion resistance, heat-oxidative aging resistance, wet-heat aging resistance and / or metal adhesion of a rubber composition.

[0025] In one or more embodiments, the use comprises adding 0.5-5 parts by mass, preferably 2-4 parts by mass, more preferably 2.5-3.5 parts by mass of the antioxidant composition to the raw materials of the rubber composition, based on 100 parts by mass of the diene elastomer contained in the raw materials of the rubber composition. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0027] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0028] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0029] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0030] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0031] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0032] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0033] In the present invention, the antioxidant A has a structure shown in Formula I:

[0034]

[0035] In the present invention, the antioxidant TMQ refers to 2,2,4-trimethyl-1,2-dihydroquinoline polymer. 2,2,4-trimethyl-1,2-dihydroquinoline polymer has a structure shown in Formula II:

[0036]

[0037] In formula II, n represents the degree of polymerization.

[0038] The present invention finds that compared with using only one or two antioxidants selected from antioxidant 6PPD, antioxidant A and antioxidant TMQ, the use of an antioxidant composition comprising antioxidant 6PPD, antioxidant A and antioxidant TMQ can make the rubber composition, especially the rubber composition for tires, have better anti-vulcanization reversion resistance, resistance to wet heat aging and adhesion to metal. In some embodiments, compared with using only one or two antioxidants selected from antioxidant 6PPD, antioxidant A and antioxidant TMQ, the use of an antioxidant composition comprising antioxidant 6PPD, antioxidant A and antioxidant TMQ can also make the rubber composition, especially the rubber composition for tires, have better heat-oxidation aging resistance, especially long-term heat-oxidation aging resistance.

[0039] Therefore, the present invention provides an antioxidant composition comprising antioxidant 6PPD, antioxidant A and antioxidant TMQ. In the antioxidant composition of the present invention, the mass ratio of antioxidant 6PPD and antioxidant A is preferably 8:1 to 1:4, more preferably 3:1 to 1:3, which is conducive to the antioxidant composition to play the effect of improving the anti-sulfurization reversion, wet heat aging resistance, heat oxygen aging resistance and / or the adhesion performance with metal of the rubber composition. More preferably, the mass ratio of antioxidant 6PPD and antioxidant A is controlled to 1:1 to 1:3, and now the antioxidant composition has the effect of better improving the anti-sulfurization reversion, wet heat aging resistance and heat oxygen aging resistance of the rubber composition.

[0040] In the antioxidant composition of the present invention, the ratio of the total mass of antioxidant 6PPD and antioxidant A to the mass of antioxidant TMQ is preferably 1: 1 to 3: 1, more preferably 1.5: 1 to 2.5: 1, such as 1.6: 1, 1.7: 1, 1.8: 1, 1.9: 1, 2: 1, 2.1: 1, 2.2: 1, 2.3: 1, 2.4: 1. This is conducive to the antioxidant composition to play the role of improving the anti-vulcanization reversion, wet heat aging resistance, heat oxygen aging resistance and / or adhesion to metals (such as steel wires) of the rubber composition.

[0041] The present invention also provides a rubber composition containing the antioxidant composition of the present invention. The raw materials of the rubber composition generally include a diene elastomer, a reinforcing filler, an antioxidant and a crosslinking agent. Herein, the rubber composition includes unvulcanized rubber and vulcanized rubber. The unvulcanized rubber can be vulcanized rubber by vulcanization (curing).

[0042] The raw materials of the rubber composition of the present invention include a diene elastomer and the antioxidant composition of the present invention, wherein the amount of the antioxidant composition of the present invention can be 0.5-5 parts by mass based on 100 parts by mass of the diene elastomer. Herein, unless otherwise specified, the mass of the diene elastomer in the raw materials of the rubber composition is taken as 100 parts by mass as a basis to calculate the mass parts of other components in the raw materials of the rubber composition.

[0043] Herein, diene elastomer refers to an elastomer whose monomers contain dienes (such as butadiene, isoprene). Suitable diene elastomers for use in the present invention may be various diene elastomers known in the art, including but not limited to one or more selected from natural rubber (NR), butadiene rubber (BR), isoprene rubber, styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), isoprene / butadiene copolymers, isoprene / styrene copolymers, and isoprene / butadiene / styrene copolymers. In some preferred embodiments, the diene elastomer contains natural rubber or consists of natural rubber.

[0044] The antioxidant contained by the rubber composition of the present invention comprises the antioxidant composition of the present invention. In some embodiments, the rubber composition of the present invention does not contain other antioxidants except the antioxidant composition of the present invention. In the raw material of the rubber composition of the present invention, the consumption of the antioxidant composition of the present invention can be 0.5-5 mass parts, preferably 2-4 mass parts, such as 2.3 mass parts, 2.5 mass parts, 2.8 mass parts, 3 mass parts, 3.2 mass parts, 3.5 mass parts, 3.7 mass parts. The consumption of the antioxidant composition of the present invention is controlled within the aforementioned range to be conducive to making the rubber composition have preferably anti-vulcanization reversion resistance, heat oxygen aging resistance, wet heat aging resistance and / or adhesion to metal while using less antioxidant.

[0045] The raw materials of the rubber composition of the present invention may include reinforcing fillers. In the raw materials of the rubber composition of the present invention, the amount of reinforcing fillers can be 30-70 parts by mass, such as 40 parts by mass, 45 parts by mass, 50 parts by mass, 55 parts by mass, and 60 parts by mass. The reinforcing fillers suitable for the present invention can be reinforcing fillers conventionally used for rubber compositions, including but not limited to one or more selected from carbon black, white carbon black, titanium oxide, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, clay, and talc. In some embodiments, the reinforcing filler includes carbon black, or the reinforcing filler is carbon black. Examples of carbon black include carbon black N326. In the rubber composition of the present invention, the amount of carbon black can be 30-70 parts by mass, such as 40 parts by mass, 45 parts by mass, 50 parts by mass, 55 parts by mass, and 60 parts by mass.

[0046] The raw materials of the rubber composition of the present invention include a crosslinking agent, such as sulfur. The sulfur is preferably insoluble sulfur. In the raw materials of the rubber composition of the present invention, the amount of sulfur can be 2-8 parts by mass, such as 3 parts by mass, 4 parts by mass, 4.4 parts by mass, 4.6 parts by mass, 4.8 parts by mass, 5 parts by mass, 6 parts by mass, and 7 parts by mass.

[0047] The raw materials of the rubber composition of the present invention may also include other ingredients that can be used in the rubber composition, including but not limited to one or more selected from softeners, protective waxes, activators, cobalt salts, rubber adhesives, accelerators, rubber scorch retardants, etc.

[0048] Softener can be used to improve the processing properties of rubber combination. Softener can include petroleum softener, such as naphthenic oil, aromatic oil, process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, vaseline etc., and also can include fatty oil softener, such as stearic acid, castor oil, linseed oil, rapeseed oil, coconut oil, wax (such as beeswax, carnauba wax and lanolin), tall oil, linoleic acid, palmitic acid, lauric acid etc. In the present invention, softener is optional to add. When the raw material of rubber combination of the present invention includes softener, the consumption of softener can be 1-10 mass parts, preferably 3-9 mass parts, such as 4 mass parts, 5 mass parts, 6 mass parts, 7 mass parts, 8 mass parts.

[0049] The protective wax can migrate from the inside of the rubber to the surface to form a wax film, which plays a role in isolating the rubber surface from the external environment. In the present invention, the protective wax is optionally added. When the raw materials of the rubber composition of the present invention include the protective wax, the amount of the protective wax can be 1-5 parts by mass, for example, 1.5 parts by mass, 2 parts by mass, 3 parts by mass, 4 parts by mass.

[0050] The activator can accelerate the vulcanization speed, improve the thermal conductivity, wear resistance, tear resistance of rubber and the like. The raw material of the rubber composition of the present invention preferably includes an activator. Examples of activators include ZnO. In the raw material of the rubber composition of the present invention, the amount of the activator can be 2-15 parts by mass, such as 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, 12 parts by mass. In some preferred embodiments, the activator includes ZnO, or the activator is ZnO. In some preferred embodiments, in the raw material of the rubber composition of the present invention, the amount of ZnO is 2-15 parts by mass, such as 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, 12 parts by mass.

[0051] Cobalt salts can play a good role in promoting rubber-steel cord adhesion. When used as a tire belt layer or carcass rubber, the raw material of the rubber composition of the present invention preferably contains cobalt salts. Cobalt salts that can be used in the present invention include but are not limited to cobalt decanoate, cobalt boroacylate and cobalt cyclohexane acid, etc. In some embodiments, the cobalt salt used in the present invention is cobalt decanoate. In the raw material of the rubber composition of the present invention, the amount of cobalt salt can be 0.1-2 parts by mass, for example 0.2 parts by mass, 0.4 parts by mass, 0.5 parts by mass, 0.6 parts by mass, 0.8 parts by mass, 1 parts by mass, 1.5 parts by mass.

[0052] The rubber adhesive is used to enhance the adhesion between the rubber and the steel cord. When used as a tire belt layer or a carcass rubber compound, the raw material of the rubber composition of the present invention preferably includes a rubber adhesive. The rubber adhesive may be a meta-formaldehyde-white system or a meta-formaldehyde system. The meta-formaldehyde-white system is composed of a resorcinol donor (e.g., resorcinol, resorcinol-formaldehyde resin, etc.), a methylene donor (e.g., hexamethoxymethyl melamine) and white carbon black. The meta-formaldehyde system is composed of a resorcinol donor and a methylene donor. The meta-formaldehyde-white system and the meta-formaldehyde system can effectively enhance the adhesion between the rubber and the steel cord. In some preferred embodiments, the rubber composition of the present invention is based on the formula of the carcass of an all-steel radial tire, and the raw materials include a resorcinol donor and a methylene donor, but do not include white carbon black, that is, the rubber adhesive is a meta-formaldehyde system. In the raw materials of the rubber composition of the present invention, the amount of the rubber adhesive may be 1-10 parts by mass, preferably 5-10 parts by mass, for example, 6 parts by mass, 7 parts by mass, 8 parts by mass, and 9 parts by mass.

[0053] When the raw materials of the rubber composition include a resorcinol donor, the amount of the resorcinol donor can be 0.5-5 parts by mass, such as 1 part by mass, 1.5 parts by mass, 1.8 parts by mass, 1.9 parts by mass, 2 parts by mass, 2.5 parts by mass, 3 parts by mass, 4 parts by mass. The resorcinol donor includes resorcinol pre-dispersed in rubber, such as resorcinol-80 (80wt% of resorcinol and 20wt% of rubber and dispersant). In some embodiments, the resorcinol donor is resorcinol-80.

[0054] The methylene donor can be hexamethoxymethyl melamine (HMMM for short), or a mixture containing HMMM. The mixture containing HMMM can be a mixture of HMMM and an inorganic carrier, such as rubber adhesive RA. Examples of rubber adhesive RA include rubber adhesive RA-65, in which the mass fraction of HMMM is 65%. In the raw materials of the rubber composition of the present invention, the amount of the methylene donor can be 1-10 parts by mass, such as 2 parts by mass, 3 parts by mass, 4 parts by mass, 5 parts by mass, 6 parts by mass, 7 parts by mass, and 8 parts by mass. In some embodiments, the methylene donor is rubber adhesive RA-65.

[0055] The rubber anti-scorch agent is used to prevent the early vulcanization of the rubber compound during the processing, and can be one or more selected from nitroso compounds (such as N-nitrosodiphenylamine), organic acids (such as benzoic acid, phthalic anhydride) and thioimides (such as N-cyclohexylthiophthalimide). In the present invention, the rubber anti-scorch agent is optionally added. When the rubber anti-scorch agent is added, the amount of the rubber anti-scorch agent in the raw materials of the rubber composition of the present invention can be 0.02-0.5 mass parts, such as 0.05 mass parts, 0.1 mass parts, 0.2 mass parts, 0.3 mass parts, 0.4 mass parts.

[0056] Accelerator is usually a vulcanization accelerator, which can be selected from sulfonamide vulcanization accelerator, thiazole vulcanization accelerator, thiuram vulcanization accelerator, thiourea vulcanization accelerator, guanidine vulcanization accelerator, dithiocarbamate vulcanization accelerator, aldehyde amine vulcanization accelerator, aldehyde ammonia vulcanization accelerator, imidazoline vulcanization accelerator and xanthate vulcanization accelerator. In the raw material of the rubber composition of the present invention, the amount of accelerator can be 0.5-5 mass parts, such as 1 mass parts, 1.2 mass parts, 1.4 mass parts, 1.5 mass parts, 1.6 mass parts, 1.8 mass parts, 2 mass parts, 3 mass parts. In some preferred embodiments, accelerator is accelerator DZ (N, N'-dicyclohexyl-2-benzothiazole sulfenamide). The mass ratio of accelerator DZ to sulphur is preferably 1:3 to 1:3.5.

[0057] In some preferred embodiments, the raw materials of the rubber composition of the present invention include: 100 parts by mass of a diene elastomer (e.g., natural rubber), 2-8 parts by mass of sulfur, 0.5-5 parts by mass of the antioxidant composition of the present invention, 30-70 parts by mass of carbon black, 2-15 parts by mass of ZnO, 0.1-2 parts by mass of a cobalt salt, 1-10 parts by mass of a rubber adhesive (e.g., a rubber adhesive RA and resorcinol-80) and 0.5-5 parts by mass of an accelerator (e.g., accelerator DZ), or are composed of the above ingredients.

[0058] The unvulcanized rubber of the present invention can be prepared by conventional rubber mixing methods, for example, by a two-stage mixing method: a first stage of thermomechanical (e.g., internal mixer) mixing, mixing the rubber composition raw materials except the crosslinking agent, rubber adhesive and accelerator, kneading the entire mixture until the maximum temperature reaches between 110°C and 190°C to obtain a first stage of rubber; a second stage of thermomechanical (e.g., open mixer) mixing, cooling the first stage of rubber to below 100°C, mixing the first stage of rubber with the crosslinking agent, rubber adhesive and accelerator until the maximum temperature is below 110°C to obtain a second stage of rubber, i.e., the unvulcanized rubber.

[0059] Vulcanized rubber can be obtained by vulcanizing (curing) the unvulcanized rubber. The vulcanization temperature is usually 130-200°C, such as 140-160°C, 150±5°C; the vulcanization time depends on the vulcanization temperature, the vulcanization system and the vulcanization kinetics, and is usually 15-60 minutes, such as 30-50 minutes, 40±5 minutes. Before vulcanization, the unvulcanized rubber can be rolled into a sheet with a thickness of 2-3 mm.

[0060] Compared with the antioxidant composition containing only one or two antioxidants selected from antioxidant 6PPD, antioxidant A and antioxidant TMQ, the rubber composition containing the antioxidant composition of the present invention is used in rubber products, such as tires, especially tire belts or tire carcasses, which can make the rubber products have better heat-oxidative aging resistance (such as long-term heat-oxidative aging resistance), wet-heat aging resistance, anti-vulcanization reversion and / or adhesion performance with metals (such as steel wires). Therefore, the present invention also provides a rubber product, which contains the rubber composition described herein. The rubber product can be a tire, a rubber shoe, a sealing strip, a sound insulation board, a shock pad, etc. The rubber product is preferably a tire, such as a tire belt, a tire carcass, etc.

[0061] The present invention also provides the antioxidant composition of the present invention in improving the heat oxygen aging resistance (e.g., long-term heat oxygen aging resistance), moisture heat aging resistance, anti-vulcanization reversion and / or the bonding performance with metal (e.g., steel wire) of a rubber composition or a rubber product, and a method for improving the heat oxygen aging resistance (e.g., long-term heat oxygen aging resistance), moisture heat aging resistance, anti-vulcanization reversion and / or the bonding performance with metal (e.g., steel wire) of a rubber composition or a rubber product. Preferably, the use or method of the present invention comprises: adding the antioxidant composition of the present invention to the raw materials of the rubber composition. In the use or method of the present invention, the amount of the antioxidant composition of the present invention and the raw material composition of the rubber composition are preferably as described in any embodiment of the present invention.

[0062] The present invention will be described below in the form of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents and materials used in the examples are, unless otherwise stated, conventional methods, reagents and materials in the art. The raw material compounds in the examples can all be purchased through commercial routes.

[0063] The sources and specifications of the raw materials used in the examples are as follows:

[0064] Natural rubber: Sinochem Rubber, SCR10;

[0065] Carbon black: Cabot, N326;

[0066] Antioxidant 6PPD: Shengao Chemical Technology Co., Ltd.;

[0067] Antioxidant A: Shengao Chemical Technology Co., Ltd.;

[0068] Antioxidant TMQ: Shengao Chemical Technology Co., Ltd.;

[0069] Zinc oxide: Yonghua Chemical Technology (Jiangsu) Co., Ltd.

[0070] Cobalt decanoate: Jiangyin Sanliang Rubber New Materials Co., Ltd.;

[0071] Resorcinol-80: Huaqi (China) Chemical Co., Ltd.;

[0072] Rubber adhesive RA-65: Wuxi Huasheng Rubber New Material Technology Co., Ltd.;

[0073] Insoluble sulfur: Eastman, HD OT-20;

[0074] Accelerator DZ: Shandong Shangshun Chemical Co., Ltd.

[0075] Example

[0076] According to the formulation shown in Table 1, rubber compositions 1-6 were prepared using the following process:

[0077] (1) a first stage of mixing is carried out in an internal mixer, natural rubber is added to the internal mixer, and then carbon black, zinc oxide, cobalt decanoate, antioxidant and resorcinol-80 are added, and the mixture is kneaded until the temperature of the rubber material reaches 150° C. to obtain a first stage of rubber;

[0078] (2) The second stage mixing is carried out on an open mill. After the first stage rubber is cooled to 50°C, the first stage rubber, rubber adhesive RA-65, insoluble sulfur and accelerator DZ are added to the open mill and mixed until the rubber temperature reaches 100°C and the rubber is discharged to obtain the second stage rubber;

[0079] (3) The second-stage rubber is rolled into a sheet and vulcanized at 151°C for 40 minutes to obtain a vulcanized rubber.

[0080] Table 1: Formulation of rubber compositions 1-6 (unit: parts by mass)

[0081]

[0082]

[0083] Test Example 1

[0084] The performance of rubber compositions 1-6 was tested according to the following standards, and the results are shown in Table 2:

[0085] The Mooney viscosity of the unvulcanized rubber compound is measured in accordance with GB / T1232.1-2016 at 100°C (ML (1+4), M stands for Mooney, L stands for large rotor, 1 stands for preheating for 1 minute, 4 stands for testing for 4 minutes, and 100°C stands for the test temperature of 100°C.

[0086] According to GB / T1233-2008, the determination of initial vulcanization characteristics of unvulcanized rubber, the Mooney scorch time t5 of the unvulcanized rubber was determined using a Mooney instrument (120°C).

[0087] According to GB / T16584-1996, the vulcanization characteristics of rubber are measured by a rotorless vulcanizer, and the positive vulcanization time t of the rubber compound is measured by a vulcanometer (151°C). 90 The time t when the torque value of the sulfur analyzer reaches the maximum and then gradually decreases to 97% of the maximum value R97 .t R97 / t 90 The larger the ratio, the better the anti-reversion property of the rubber. Testing conditions of the sulfur analyzer: 151℃*100min.

[0088] According to GB / T528-2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber, the elongation at break, tensile strength and constant elongation load of the vulcanized rubber are measured. Tensile product = elongation at break × tensile strength. Tensile product retention rate = tensile product after thermal oxidative aging / tensile product before thermal oxidative aging × 100%. MA100 and MA300 represent the tensile strength of the vulcanized rubber at an elongation of 100% and 300%, respectively.

[0089] The tear strength of vulcanized rubber was determined according to GB / T529-2008 Determination of tear strength of vulcanized rubber.

[0090] According to GB / T3512-2014 vulcanized rubber or thermoplastic rubber hot air accelerated aging and heat resistance test, the vulcanized rubber thermal oxygen aging test was carried out. Experimental conditions: 100℃*48h.

[0091] Table 2: Performance test results of rubber compositions 1-6

[0092]

[0093]

[0094] Test Example 2: Metal Bonding Test

[0095] The bonding strength between vulcanized rubber and steel cord according to GB / T16586-1996 was tested on an electronic tensile machine to test the bonding performance between vulcanized rubber and metal before and after aging. The results are shown in Table 3. The methods of various aging tests are as follows:

[0096] Thermal oxidative aging: GB / T3512-2014 vulcanized rubber or thermoplastic rubber hot air accelerated aging and heat resistance test, the test conditions are 100℃*7d and 100℃*14d.

[0097] Damp heat aging: The test conditions are aging box temperature 85℃, relative humidity 95%, and aging time 7 days. Other conditions refer to GB / T15905-1995 vulcanized rubber damp heat aging test method.

[0098] Adhesion retention rate = adhesion before aging / adhesion after aging × 100%

[0099] Table 3: Adhesion performance test results of rubber compositions 1-6

[0100]

[0101]

[0102] As can be seen from Table 2, the physical properties of the rubber compositions are similar before aging. After 100°C*48h thermal aging, the anti-sulfurization reversion performance of the rubber compositions 2-4, especially the rubber composition 3-4, containing the antioxidant composition of the present invention is better than that of the rubber compositions 1, 5 and 6. R97 and t R97 / t 90 The improvement is more than 10% compared with the rubber composition 1, and about 5% compared with the rubber composition 5. At the same time, compared with the rubber compositions 1, 5 and 6, the rubber compositions 2-4 containing the antioxidant composition of the present invention also have better tensile properties after thermal oxidation aging, indicating that the rubber compositions 2-4, especially the rubber compositions 3-4, have significantly improved thermal oxidation and aging resistance.

[0103] As can be seen from Table 3, compared with rubber composition 1, 5 and 6, the rubber composition 2-4 comprising the antioxidant composition of the present invention showed significantly improved adhesion to metal before aging. Compared with rubber composition 1, 5 and 6, after wet heat aging, rubber composition 2-4 has a higher adhesion retention rate, indicating that rubber composition 2-4, particularly rubber composition 3-4, has significantly improved wet heat aging resistance. After long-term (14 days) thermal oxidative aging, the adhesion of rubber composition 2-4 is significantly higher than that of rubber composition 1, 5 and 6, and its adhesion and adhesion retention rate can be improved by more than 10%, indicating that rubber composition 2-4, particularly rubber composition 3-4, has significantly improved long-term thermal oxidative aging resistance.

Claims

1. An antioxidant composition, characterized in that The antioxidant composition comprises antioxidant 6PPD, antioxidant TMQ and antioxidant A shown in formula I:

2. The antioxidant composition according to claim 1, characterized in that In the antioxidant composition, the mass ratio of antioxidant 6PPD to antioxidant A is 8:1 to 1:4, preferably 3:1 to 1:

3.

3. The antioxidant composition according to claim 1, characterized in that In the antioxidant composition, the ratio of the total mass of antioxidant 6PPD and antioxidant A to the mass of antioxidant TMQ is 1:1 to 3:1, preferably 1.8:1 to 2.2:

1.

4. A rubber composition, characterized in that: The raw materials of the rubber composition include 100 parts by mass of a diene elastomer and 0.5 to 5 parts by mass of the antioxidant composition according to any one of claims 1 to 3.

5. The rubber composition according to claim 4, characterized in that In the raw materials of the rubber composition, the antioxidant composition is used in an amount of 2-4 parts by mass, preferably 2.5-3.5 parts by mass.

6. The rubber composition according to claim 4, characterized in that The rubber composition has one or more of the following characteristics: The diene elastomer is natural rubber; The raw materials of the rubber composition further include 30-70 parts by mass of a reinforcing filler; the reinforcing filler preferably comprises carbon black; The raw materials of the rubber composition further include 2-15 parts by mass of an active agent; the active agent preferably includes zinc oxide; The raw materials of the rubber composition further include 0.1-2 parts by mass of a cobalt salt; the cobalt salt preferably comprises cobalt decanoate; The raw materials of the rubber composition further include 1-10 parts by mass of a rubber adhesive; the rubber adhesive preferably comprises a resorcinol donor and a methylene donor; The raw materials of the rubber composition also include 2-8 parts by mass of sulfur; The raw materials of the rubber composition further include 0.5-5 parts by mass of an accelerator; the accelerator preferably comprises N,N'-dicyclohexyl-2-benzothiazolesulfenamide.

7. A rubber product, characterized in that: The rubber product comprises the rubber composition according to any one of claims 4 to 6.

8. The rubber product according to claim 7, characterized in that The rubber composition is a tire band or a tire carcass.

9. Use of the antioxidant composition according to any one of claims 1 to 3 in improving the anti-vulcanization reversion resistance, thermal oxygen aging resistance, wet heat aging resistance and / or metal adhesion of a rubber composition.

10. The use according to claim 9, characterized in that The use comprises adding 0.5-5 parts by mass, preferably 2-4 parts by mass, more preferably 2.5-3.5 parts by mass of the antioxidant composition to the raw materials of the rubber composition, based on 100 parts by mass of the diene elastomer contained in the raw materials of the rubber composition.

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