A rubber composition and a method for producing the same

Abstract

The present application relates to a kind of rubber compositions and its preparation method.The rubber composition, with 100 weight parts of rubber as benchmark, comprising crosslinking agent 0.1~3 weight parts, first compound, second compound, the total addition amount of the first compound and second compound is 0.1~10 weight parts.The first compound and second compound of the present application are added to the rubber composition, and the obtained rubber composition has good static and dynamic ozone aging resistance.Compared with traditional antioxidant 6PPD, the first compound and second compound of the present application only need lower dosage, and the rubber composition can show better crack resistance under the same ozone aging condition, thereby effectively prolonging the service life of rubber products.

Description

Technical Field

[0001] This invention relates to the field of rubber materials, and more specifically, to a rubber composition and a method for preparing the same. Background Technology

[0002] Rubber, as an important polymer material, is commonly found in various aspects of life. Rubber products are inevitably subjected to various aging factors such as light, heat, oxygen, ozone, and mechanical stress during processing, storage, and actual use. Based on different aging mechanisms, rubber aging is currently mainly divided into thermo-(photo-)oxidative aging, ozone aging, and fatigue aging. The anti-aging properties of different types of rubber materials are independent of each other. For example, excellent resistance to thermo-oxidative aging does not necessarily mean that the rubber material also has resistance to ozone aging. When pursuing different anti-aging properties of rubber materials, the protective measures used in the industry often differ (such as selecting different antioxidants).

[0003] The mechanism of ozone aging involves ozone attacking the unsaturated double bonds in rubber molecules, causing cracks on the rubber surface. In other words, ozone aging primarily occurs on the rubber surface. These cracks propagate under stress, significantly reducing the lifespan of rubber products. The destructive effects of ozone aging are particularly pronounced in diene rubbers containing unsaturated double bonds.

[0004] To address the ozone aging resistance of rubber, corresponding antioxidants have been developed and applied. Examples include p-phenylenediamine antioxidants (see patent applications CN114105895A and CN119330840A), cycloene antioxidants (see patent application JP2020172577A), and thiourea antioxidants (see patent application CN110229388A). Among these, p-phenylenediamine antioxidants are the most widely used ozone antioxidants. However, with increasingly demanding rubber application scenarios (such as high ozone concentrations and long-term dynamic fatigue), existing antioxidants still suffer from insufficient protective effectiveness and limited protective durability. Therefore, new technologies need to be developed to obtain rubber materials with good ozone aging resistance to meet increasingly demanding application scenarios. Summary of the Invention

[0005] The primary objective of this invention is to overcome the problem of poor ozone resistance in existing rubber materials and to provide a rubber composition.

[0006] A further object of the present invention is to provide a method for preparing the above-mentioned rubber composition.

[0007] A further object of the present invention is to provide a rubber product.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution: A rubber composition, based on 100 parts by weight of rubber, comprises 0.1 to 3 parts by weight of a crosslinking agent, a first compound, and a second compound, wherein the total amount of the first compound and the second compound added is 0.1 to 10 parts by weight; The mass ratio of the first compound to the second compound is (50~99.95):(0.05~50). The first compound is at least one of the compounds with the structure shown in Formula I, and the second compound is at least one of the compounds with the structure shown in Formula II;

[0009] Formula I In Formula I: R1 is hydrogen, C1~C 24 Alkyl, C2-C 24 alkenyl, C2-C 24 Alkyne group, C2-C 24 Alkoxyalkyl, C1-C 24 Hydroxyalkyl, C2-C 24 Cyanoalkyl, C3-C 24 Esteryl alkyl, C6-C 20 Aryl or C7~C 24 Aryl groups; R3, R4, and R5 are each independently hydrogen, C1-C6 alkyl, C2-C6 alkenyl, or C6-C6 alkyl. 12 Aryl; R2 and A - It is one of the following (a) to (b): (a) A - It pairs with the imidazolium cation via ionic bonds to form the imidazolium exosalt, where R2 is hydrogen and C1-C2. 24 Alkyl, C2-C 24 alkenyl, C2-C 24 Alkyne group, C2-C 24 Alkoxyalkyl, C1-C 24 Hydroxyalkyl, C2-C 24 Cyanoalkyl, C3-C 24 Esteryl alkyl, C6-C 20 Aryl or C7~C 24 Aryl alkyl group, and R1 and R2 are not both hydrogen; (b) A - It is covalently linked to R2, and then binds to the imidazole ring via R2 to form an imidazole inner salt, where R2 is C1 to C2. 24 Alkylene, C2-C 24 alkenyl, C2-C 24 Ethyne group, C6-C 20 aryl or C7~C24 arylene alkyl groups;

[0010] Formula II In Formula II: R6 and R7 are each independently selected from hydrogen, C1 to C2. 12 Alkyl, C2-C 12 Alkenyl, C2~C 12 Alkyne group, C1-C 24 Hydroxyalkyl, C2-C 24 Alkoxyalkyl, C2-C 24 Cyanoalkyl, C3-C 24 Esteryl alkyl, C6-C 12 Aryl or C7~C 18 Aryl alkyl group, and at least one of R6 and R7 is hydrogen; R8, R9, R 10 Each is independently selected from hydrogen, C1 to C2. 12 Alkyl, C2-C 12 alkenyl, C2-C 12 Alkyne group, C1-C 24 Hydroxyalkyl, C2-C 24 Alkoxyalkyl, C2-C 24 Cyanoalkyl, C3-C 24 Esteryl alkyl, C6-C 12 Aryl or C7~C 18 Aryl alkyl group.

[0011] In this invention, the total amount of the first compound and the second compound can be any range consisting of 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 10 parts, or more.

[0012] In this invention, the mass ratio of the first compound and the second compound can specifically be 50:50, 51:49, 52:48, 53:47, 54:46, 55:45, 56:44, 57:43, 58:42, 59:41, 60:40, 61:39, 62:38, 63:37, 64:36, 65:35, 66:34, 67:33, 68:32, 69:31, 70:30, 71:29, 72:28, 73:27, 74:26, 75:25, 76:24, 77:23, 78:22, or 79:2 1. An interval range consisting of 80:20, 81:19, 82:18, 83:17, 84:16, 85:15, 86:14, 87:13, 88:12, 89:11, 90:10, 91:9, 92:8, 93:7, 94:6, 95:5, 96:4, 97:3, 98:2, 99:1, 99.5:0.5, 99.6:0.4, 99.7:0.3, 99.8:0.2, 99.9:0.1, 99.92:0.08, 99.94:0.06, 99.95:0.05, or any two of the above.

[0013] Preferably, the mass ratio of the first compound to the second compound is (70~99.9):(0.1~30).

[0014] More preferably, the mass ratio of the first compound to the second compound is (95~99.5):(0.5~5).

[0015] By adjusting the mass ratio of the first compound and the second compound within a certain range, the ozone aging resistance of the rubber composition can be improved.

[0016] Preferably, the rubber refers to an elastomer formed by polymerizing monomers containing dienes.

[0017] More preferably, the diene includes at least one of butadiene, isoprene, 2-chloro-1,3-butadiene, dicyclopentadiene, or hexadiene.

[0018] Preferably, the rubber includes at least one of natural rubber (NR), butadiene rubber (BR), isoprene rubber, styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), ethylene propylene diene monomer (EPDM), isoprene / butadiene copolymer, isoprene / styrene copolymer, or isoprene / butadiene / styrene copolymer.

[0019] In some preferred embodiments, the rubber comprises both natural rubber and butadiene rubber, and the mass ratio of natural rubber to butadiene rubber is 1:(0.2~5), preferably 1:(1~2). The natural rubber / butadiene rubber compound system is a commonly used rubber system in tire sidewall rubber, which can balance mechanical strength, flexural fatigue resistance and processing performance.

[0020] In some preferred embodiments, the rubber comprises both natural rubber and styrene-butadiene rubber (SBR), and the mass ratio of natural rubber to SBR is 1:(0.2~5), preferably 1:(1~2). The natural rubber / SBR compound system is a commonly used rubber system in semi-steel tire tread compounds, which can balance mechanical strength, abrasion resistance, and formulation adaptability.

[0021] It should be understood that any type of rubber can be used in this invention. The invention is specifically illustrated using an elastomer formed by polymerizing monomers containing dienes as an example because such rubbers have a higher requirement for ozone resistance.

[0022] It should be understood that the rubber compound systems listed in this article are merely examples to meet the application performance requirements of specific products, and these specific examples are not intended to limit the scope of protection of this invention.

[0023] Preferably, the weight-average molecular weight of the rubber is 5 × 10⁻⁶. 4 ~2×10 6 g / mol; specifically, it can be 5 × 10⁻⁶ g / mol. 4 6×10 4 7×10 4 8×10 4 9×10 4 1×10 5 2×10 5 3×10 5 4×10 5 5×10 5 6×10 5 7×10 5 8×10 5 9×10 5 1×10 6 2×10 6 The range consisting of g / mol or any two of the above.

[0024] Preferably, the amount of the crosslinking agent is 0.5 to 1.8 parts by weight.

[0025] Preferably, the crosslinking agent includes, but is not limited to, sulfur.

[0026] Preferably, based on 100 parts by weight of rubber, the rubber composition further comprises 0.1 to 120 parts by weight of filler.

[0027] More preferably, the amount of filler used is 5 to 110 parts, even more preferably 50 to 110 parts, and even more preferably 50 to 70 parts.

[0028] The fillers suitable for use in this invention can be fillers conventionally used in rubber compositions, including but not limited to at least one selected from carbon black, silica, titanium dioxide, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, clay, or talc, preferably carbon black and / or silica. Typically, the average particle size of the filler is 5 nm to 100 μm.

[0029] Preferably, based on 100 parts by weight of rubber, the rubber composition further comprises 0.5 to 15 parts by weight of a softener.

[0030] More preferably, the amount of the softener is 1 to 3 parts by weight.

[0031] Optionally, the softener includes, but is not limited to, at least one of naphthenic oil, aromatic oil, paraffin, petroleum asphalt, petrolatum, castor oil, linseed oil, rapeseed oil, coconut oil, tall oil, linoleic acid, palmitic acid, lauric acid, beeswax, carnauba wax, or lanolin, preferably aromatic oil and / or naphthenic oil.

[0032] Preferably, based on 100 parts by weight of rubber, the rubber composition further comprises 1 to 10 parts by weight of an activator.

[0033] More preferably, the amount of the activator is 3 to 8 parts by weight.

[0034] Optionally, the activator includes, but is not limited to, at least one of stearic acid or zinc oxide.

[0035] In some preferred embodiments, the activator comprises both stearic acid and zinc oxide in a mass ratio of 1:(1~6).

[0036] Preferably, based on 100 parts by weight of rubber, the rubber composition further comprises 0.2 to 5 parts by weight of an accelerator.

[0037] More preferably, the accelerator is a vulcanization accelerator, including but not limited to at least one of sulfonamide vulcanization accelerators, thiazole vulcanization accelerators, thiuram vulcanization accelerators, guanidine vulcanization accelerators, dithiocarbamate vulcanization accelerators, aldehyde-amine vulcanization accelerators, aldehyde-amine vulcanization accelerators, imidazoline vulcanization accelerators, or xanthic acid vulcanization accelerators.

[0038] More preferably, the accelerator is at least one of accelerator D (1,3-diphenylguanidine), accelerator NS (N-tert-butyl-2-benzothiazole sulfenamide), accelerator TMTD (tetramethylthiuram disulfide), accelerator CZ (N-cyclohexyl-2-benzothiazole sulfenamide), accelerator MBT (2-thiol-benzothiazole), or accelerator DM (2,2'-dithiodibenzothiazole).

[0039] In some preferred embodiments, the accelerator simultaneously comprises accelerator D (1,3-diphenylguanidine), accelerator TMTD (tetramethylthiuram disulfide), and accelerator CZ (N-cyclohexyl-2-benzothiazole sulfenamide), with a mass ratio of 1:(0.1~4):(0.1~2), preferably 1:(0.1~0.5):(0.2~0.5).

[0040] In some preferred embodiments, the accelerator comprises both accelerator DM (2,2'-dithiodibenzothiazole) and accelerator MBT (2-thiol-benzothiazole) in a mass ratio of 1:(0.1~3), preferably 1:(0.3~1).

[0041] Preferably, based on 100 parts by weight of rubber, the rubber composition further comprises 0 to 5 parts by weight of tackifying resin.

[0042] Optionally, the tackifying resin includes, but is not limited to, at least one of petroleum resin, octylphenol tackifying resin, or rosin resin.

[0043] Preferably, based on 100 parts by weight of rubber, the rubber composition further comprises 0 to 10 parts by weight of plasticizer.

[0044] Preferably, the amount of plasticizer used is 3 to 6 parts by weight.

[0045] Optionally, the plasticizer includes, but is not limited to, at least one of DMP (dimethyl phthalate), DEP (diethyl phthalate), DBP (dibutyl phthalate), DHP (diheptyl phthalate), DOP (dioctyl phthalate), DINP (diisononyl phthalate), DIDP (diisodecyl phthalate), BBP (butyl benzyl phthalate), DWP (dilauryl phthalate), or DCHP (dicyclohexyl phthalate).

[0046] Preferably, based on 100 parts by weight of rubber, the rubber composition further comprises 0 to 10 parts by weight of coupling agent.

[0047] Optionally, the coupling agent is a silane coupling agent, including but not limited to at least one of bis-[γ-(triethoxysilane)propyl]tetrasulfide, 3-octanoylthiopropyltriethoxysilane, 3-thiocyanopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, or bis-[3-(triethoxysilane)propyl]-disulfide.

[0048] It should be noted that the components in the rubber composition of the present invention, other than the first compound, the second compound, and the crosslinking agent, including fillers, softeners, activators, accelerators, tackifying resins, plasticizers, coupling agents, etc., are all conventional additives in the art, and their types and amounts can be conventionally selected and adjusted according to actual functional requirements. Even if one or more of the above-mentioned additives are missing, it will not affect the intended technical effects of the first compound and the second compound in the present invention.

[0049] Preferably, the A - When A pairs with an imidazolium cation via an ionic bond to form an imidazolium exosalt, - BF4 - PF6 - ClO4 - NO3 - HSO4 - H2PO4 - ROSO3 - , RSO3 - F - Cl - ,Br - I - ArSO3 - RCOO - RfCOO - ROPO3H - (RO)2PO2 - , RPO2H - SCN - N(CN)2 - C(CN)3 - N(SO2CF3)2 - N(SO2F)2 - N(SO2C2F5)2 - C n F 2n+1 SO3 - , RfSO3 - BF3R - BF3Rf - Or [M(Y)] p ] - Where R is C1 to C2. 12Alkyl group, Ar is C6~C6 20 Aryl, Rf is C1~C 12 Fluoroalkyl, n is an integer from 1 to 12, M is a metal center, Y is a monovalent anion ligand, and p is an integer from 1 to 6; The A - When A is covalently linked to R2 and then to the imidazole ring via R2 to form an imidazole inner salt, - It can be a carboxylate group, sulfonate group, hydrogen phosphate group, phosphate ester group, or sulfate ester group.

[0050] More preferably, the C1 to C 12 The fluoroalkyl group is C1 to C2. 12 Perfluoroalkyl.

[0051] More preferably, p is 1, 2, 3, 4, 5 or 6.

[0052] More preferably, M is Fe 3+ Or Al 3+ .

[0053] More preferably, the Y is Cl - .

[0054] In this invention, C1 to C are mentioned throughout the text. 12 Alkyl groups, unless otherwise specified, are alkyl groups having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms; the C1 to C2 groups are alkyl groups with 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms. 12 Fluoroalkyl refers to a fluoroalkyl group having 1 to 12 carbon atoms, wherein the number of carbon atoms is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; the C1 to C12 carbon atoms are... 12 Perfluoroalkyl refers to perfluoroalkyl groups having 1 to 12 carbon atoms, wherein the number of carbon atoms is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

[0055] In this invention, C1 to C 24 Alkylene refers to an alkylene having 1 to 24 carbon atoms, wherein the number of carbon atoms is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24; the C2 to C3... 24 An alkenyl group refers to an alkenyl group having 2 to 24 carbon atoms, wherein the number of carbon atoms is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24; the C2 to C 24The term "ethynyl group" refers to an ethynyl group having 2 to 24 carbon atoms, wherein the number of carbon atoms is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24.

[0056] Preferably, the compound having the structure shown in Formula I satisfies at least one of the following (1) to (3): (1) R1 is hydrogen or C1~C 24 alkyl; (2) R3, R4, and R5 are each independently hydrogen or C1-C6 alkyl; (3) The A mentioned - When R2 pairs with an imidazolium cation via an ionic bond to form an imidazolium exosalt, it is either hydrogen or C1-C2. 24 Alkyl, A - For Cl - CH3COO - CH3SO3 - ,Br - CF3SO3 - (C4H9O)2PO2 - H2PO4 - CF3COO - N(CN)2 - I - or OH - And R1 and R2 are not both hydrogen; or the A - When R2 is covalently linked to R2 and then binds to the imidazole ring via R2 to form an imidazole inner salt, R2 has a C1 to C2 configuration. 24 Alkylene, A - It is a sulfonate group.

[0057] In this invention, C1 to C are mentioned throughout the text. 24 Alkyl groups, unless otherwise specified, refer to alkyl groups having 1 to 24 carbon atoms, wherein the number of carbon atoms is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24.

[0058] In this invention, C1 to C6 alkyl groups mentioned throughout the text, unless otherwise specified, are alkyl groups with 1 to 6 carbon atoms, wherein the number of carbon atoms is 1, 2, 3, 4, 5 or 6.

[0059] More preferably, the A - When R2 is covalently linked to R2 and then bonded to an imidazole ring via R2 to form an imidazole inner salt, R2 is a C1-C6 alkylene group; more preferably, the C1-C6 alkylene group is a butylene group.

[0060] Preferably, the compound having the structure shown in Formula II satisfies at least one of the following (1) to (2): (1) R6 and R7 are each independently selected from hydrogen, C1-C6 alkyl, C2-C7 alkenyl or C7-C 12 Aryl groups; (2) R8, R9, R 10 Each is independently selected from hydrogen or C1 to C6 alkyl groups.

[0061] In this invention, the C2-C7 alkenyl group refers to an alkenyl group having 2 to 7 carbon atoms, wherein the number of carbon atoms is 2, 3, 4, 5, 6 or 7.

[0062] In this invention, C7 to C 12 Araneyl groups are araneyl groups having 7 to 12 carbon atoms, wherein the number of carbon atoms is 7, 8, 9, 10, 11 or 12.

[0063] Preferably, the compound having the structure shown in Formula I is at least one of 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium methanesulfonate, 1-hexadecyl-3-methylimidazolium bromide, 1-sulfobutyl-3-methylimidazolium inner salt, 1-n-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium dibutyl phosphate, 1-vinyl-3-butylimidazolium chloride, 1-butyl-3-methylimidazolium dihydrogen phosphate, 1-butyl-2,3-dimethylimidazolium chloride, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium bromide, 1-hexadecyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium dicyandiamide, 1-butyl-3-methylimidazolium iodide, or 1-butyl-3-methylimidazolium hydroxide.

[0064] Preferably, the compound having the structure shown in Formula II is at least one of 1-methylimidazole, 1-ethylimidazole, 1-propylimidazole, 1-butylimidazole, 1-ethyl-2-methylimidazole, 1-methyl-2-ethylimidazole, 1-butyl-2-methylimidazole, 1-vinylimidazole, 1-allylimidazole, 1,2-dimethylimidazole, 1-benzylimidazole, 1-phenylimidazole, 2-methylimidazole, or 4-methylimidazole.

[0065] The preparation method of the above rubber composition includes the following steps: first, mixing rubber with components other than crosslinking agent and accelerator, then adding crosslinking agent and accelerator, mixing and vulcanizing to obtain the rubber composition.

[0066] Preferably, the method for preparing the rubber composition includes the following steps: S1. The rubber is mixed with the components other than the crosslinking agent and accelerator in an internal mixer, and the rubber is discharged to obtain a first-stage compound; S2. The first-stage compound is re-mixed in a two-roll mill, crosslinking agent and accelerator are added, mixed, and sheeted to obtain the second-stage compound; S3. The two-stage compound is vulcanized to obtain the rubber composition.

[0067] More preferably, in step S1, the timing of the glue discharge is when the temperature of the glue material rises to the set glue discharge temperature.

[0068] More preferably, the glue discharge temperature is 110~170℃.

[0069] More preferably, in step S2, the temperature of the sheet being extruded is 35~110℃.

[0070] More preferably, in step S3, the vulcanization temperature is 135~200℃ and the time is 6~60min.

[0071] A rubber article comprising the above-described rubber composition.

[0072] In this invention, the rubber product can be any type of rubber product, especially those requiring long-term ozone aging resistance, such as tires, rubber shoes, sealing strips, sound insulation panels, or vibration damping pads. It is particularly suitable for tire products, specifically as sidewall rubber or tread rubber.

[0073] Compared with the prior art, the beneficial effects of the present invention are: This invention incorporates a specific first compound (imidazolium-type compound) and a specific second compound (imidazolium compound) in a specific mass ratio into a rubber composition. The resulting rubber composition exhibits excellent static and dynamic ozone aging resistance. The overall static and dynamic ozone aging resistance levels are superior to those achieved by adding only the specific first compound or only the specific second compound. The hypothesized mechanism is that the imidazolium heterocycle of the specific first compound can act as a preferential site for ozone or ozone oxidation intermediates, competitively consuming ozone and reducing the direct attack of ozone on the double bonds of the main molecular chain on the surface of the rubber composition. Meanwhile, the specific second compound can improve the dispersibility of the specific first compound in the rubber composition, thereby further enhancing the competitive consumption of ozone or ozone oxidation intermediates by the specific first compound. The synergistic effect of the two compounds can significantly delay the initiation and propagation of ozone cracks, improving the static and dynamic ozone aging resistance of the rubber composition.

[0074] Compared with the traditional antioxidant 6PPD, the total addition amount of the first and second compounds of the present invention can make the rubber composition exhibit better crack resistance under the same ozone aging conditions with a lower amount, thereby effectively extending the service life of rubber products. Detailed Implementation

[0075] To more clearly and completely describe the technical solution of the present invention, the present invention will be further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Various changes can be made within the scope of the claims of the present invention.

[0076] The following describes some of the raw materials or reagents used in the embodiments and comparative examples of this invention: I. Compound 1 and Compound 2 In this invention, the first compound and the second compound are pre-mixed evenly according to the required ratio, and the resulting mixture is referred to as a complex, as follows: Complex A: is obtained by mixing 99.95 parts by weight of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 0.05 parts by weight of 1-methylimidazolium; Complex B: is obtained by mixing 99.9 parts by weight of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 0.1 parts by weight of 1-methylimidazolium; Complex C: is obtained by mixing 99.5 parts by weight of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 0.5 parts by weight of 1-methylimidazolium; Complex D: is obtained by mixing 98 parts by mass of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 2 parts by mass of 1-methylimidazolium; Complex E: is obtained by mixing 95 parts by mass of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 5 parts by mass of 1-methylimidazolium; Complex F: is obtained by mixing 90 parts by mass of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 10 parts by mass of 1-methylimidazolium; Complex G: is obtained by mixing 80 parts by mass of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 20 parts by mass of 1-methylimidazolium; Complex H: is obtained by mixing 70 parts by mass of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 30 parts by mass of 1-methylimidazolium; Complex I: is obtained by mixing 60 parts by mass of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 40 parts by mass of 1-methylimidazolium; Complex J: is obtained by mixing 50 parts by mass of 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate and 50 parts by mass of 1-methylimidazolium; Complex K: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazolium acetate and 2 parts by mass of 1-methylimidazolium; Complex L: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazolium methanesulfonate and 2 parts by mass of 1-ethylimidazolium; Complex M: is obtained by mixing 98 parts by mass of 1-hexadecyl-3-methylimidazolium bromide and 2 parts by mass of 1-propylimidazolium; Complex N: is obtained by mixing 98 parts by mass of 1-sulfobutyl-3-methylimidazolium salt and 2 parts by mass of 1-butylimidazolium; Complex O: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazolium chloride and 2 parts by mass of 1-methylimidazolium; Complex P: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazolium dibutyl phosphate salt and 2 parts by mass of 1-methyl-2-ethylimidazolium; Complex Q: is obtained by mixing 98 parts by mass of 1-vinyl-3-butylimidazolium chloride and 2 parts by mass of 1-butyl-2-methylimidazolium; Complex R: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazolium dihydrogen phosphate and 2 parts by mass of 1-vinylimidazolium; Complex S: is obtained by mixing 98 parts by mass of 1-butyl-2,3-dimethylimidazolium chloride and 2 parts by mass of 1-allylimidazolium; Complex T: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazolium trifluoroacetate and 2 parts by mass of 1-allylimidazolium; Complex U: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazolium bromide and 2 parts by mass of 1,2-dimethylimidazolium; Complex V: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazolium dicyandiamide salt and 2 parts by mass of 1-benzylimidazolium; Complex W: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazole iodide and 2 parts by mass of 1-phenylimidazole; Complex X: is obtained by mixing 98 parts by mass of 1-hexadecyl-3-methylimidazole chloride and 2 parts by mass of 2-methylimidazole; Complex Y: is obtained by mixing 98 parts by mass of 1-butyl-3-methylimidazolium hydroxide and 2 parts by mass of 4-methylimidazolium.

[0077] All components in each complex are commercially available products; It should be noted that the premixing operation of the first compound and the second compound does not limit the technical solution; in actual application, the premixing step can also be omitted, and the first compound and the second compound can be added independently. Neither implementation method affects the realization of the technical effect of this solution.

[0078] II. Other Anti-aging agent 6PPD, commercially available; Natural rubber: Xishuangbanna Sinochem Rubber Co., Ltd., SCR5; Butadiene rubber: PetroChina Daqing, BR9000; SSBR: Jilin Chemical Co., Ltd., 2466; NBR: Zeon Corporation, Japan, DN003; EPDM: Jilin Chemical Co., Ltd., 3080; Carbon black N660, carbon black N330, carbon black N550 and carbon black N234 were all purchased from Cabot Corporation; Silica: TSRC Corporation, GR9000; Silane coupling agent: bis-[γ-(triethoxysilyl)propyl]tetrasulfide, Aladdin Reagents Ltd., AR; Zinc oxide, stearic acid, accelerator NS, accelerator D, accelerator TMTD, accelerator CZ, accelerator DM, accelerator MBT and sulfur were all purchased from Aladdin Reagent Co., Ltd. Aromatic oil: Shanghai Titan, AR.

[0079] The performance test requirements for the embodiments and comparative examples of the present invention are as follows: I. Physical and Mechanical Performance Testing The test was conducted in accordance with GB / T528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0080] II. Ozone Aging Test The rubber composition was subjected to ozone aging test in an ozone aging test chamber according to the following standards: Static ozone aging: GB / T 7762-2014 "Static tensile test for ozone cracking resistance of vulcanized rubber or thermoplastic rubber"; Dynamic ozone aging: GB / T 13642-2015 "Dynamic tensile test for ozone cracking resistance of vulcanized rubber or thermoplastic rubber"; Crack grade evaluation: GB / T 11206-2009 "Rubber Aging Test - Surface Cracking Method", the grades from best to worst are 0, 1a, 1b, 1c, 2a, 2b, 2c, 3a, 3b, 3c, 4a, 4b, 4c; The specific test parameters are as follows: ozone volume concentration 50 pphm, temperature (40±2)℃, humidity (60±5)%. During static testing, the sample was pre-stretched by 20%, and cracking was observed periodically. During dynamic testing, the sample was pre-stretched by 20%, dynamically stretched by 20%, at a frequency of 0.5Hz, and cracking was observed.

[0081] Examples 1-25 and Comparative Examples 1-3 Examples 1-25 and Comparative Examples 1-3 provide a series of rubber compositions, the preparation methods of which include the following steps: (1) Add all components except accelerator and sulfur to the internal mixer and knead until the rubber temperature rises to 130°C and then discharge the rubber to obtain a first-stage compound. (2) After the first stage of compound is cooled, the first stage of compound is rolled on a rolling mill, accelerator NS and sulfur are added, and kneaded until the temperature of the rubber compound reaches 70°C and then sheeted out to obtain the second stage of compound. (3) The two-stage compound was vulcanized (at a temperature of 145°C for 35 minutes) to obtain a rubber composition; The dosage of each component and the performance test results of Examples 1-25 and Comparative Examples 1-3 are shown in Tables 1-3.

[0082] Table 1

[0083] Table 2

[0084] Table 3

[0085] Example 26 and Comparative Examples 4-6 Examples 26 and Comparative Examples 4-6 provide a series of rubber compositions, prepared by the following steps: (1) Add all components except accelerator and sulfur to the internal mixer and knead until the rubber temperature rises to 150°C and then discharge the rubber to obtain a first-stage compound. (2) After the first stage of compound rubber cools down, the first stage of compound rubber is rolled on a rolling mill, and accelerator D, accelerator NS and sulfur are added. When the rubber temperature reaches 70°C, the mixture is sheeted out to obtain the second stage of compound rubber. (3) The two-stage compound was vulcanized (at a temperature of 150°C for 35 minutes) to obtain a rubber composition; The dosage of each component and the performance test results of Examples 26 and Comparative Examples 4-6 are shown in Table 4.

[0086] Table 4

[0087] Example 27 and Comparative Examples 7-9 Examples 27 and Comparative Examples 7-9 provide a series of rubber compositions, the preparation methods of which include the following steps: (1) Add all components except accelerator and sulfur to the internal mixer and knead until the rubber temperature rises to 110°C and then discharge the rubber to obtain a first-stage compound. (2) After the first stage of compound rubber cools down, the first stage of compound rubber is refining on a two-roll mill, and accelerator D, accelerator TMTD, accelerator CZ and sulfur are added to obtain the second stage of compound rubber. (3) The two-stage compound was vulcanized (at a temperature of 170°C for 30 minutes) to obtain a rubber composition; The dosage of each component and the performance test results of Examples 27 and Comparative Examples 7-9 are shown in Table 5.

[0088] Table 5

[0089] Example 28 and Comparative Examples 10-12 Examples 28 and Comparative Examples 10-12 provide a series of rubber compositions, prepared by the following steps: (1) Add all components except accelerator and sulfur to the internal mixer and knead until the rubber temperature rises to 100°C and then discharge the rubber to obtain a first-stage compound. (2) After the first stage of compound is cooled, the first stage of compound is milled on a two-roll mill, and accelerator DM, accelerator MBT and sulfur are added to obtain the second stage of compound. (3) The two-stage compound was vulcanized (at a temperature of 170°C for 30 minutes) to obtain a rubber composition; The dosage of each component and the performance test results of Examples 28 and Comparative Examples 10-12 are shown in Table 6.

[0090] Table 6

[0091] Example 29 and Comparative Examples 13-15 Examples 29 and Comparative Examples 13-15 provide a series of rubber compositions prepared by the following steps: (1) Add all components except accelerator and sulfur to the internal mixer and knead until the rubber temperature rises to 130°C and then discharge the rubber to obtain a first-stage compound. (2) After the first stage of compound is cooled, the first stage of compound is milled on a two-roll mill, and accelerator NS and sulfur are added to obtain the second stage of compound. (3) The two-stage compound was vulcanized (at a temperature of 143°C for 40 min) to obtain a rubber composition; The dosage of each component and the performance test results of Examples 29 and Comparative Examples 13-15 are shown in Table 7.

[0092] Table 7

[0093] As shown in Tables 1-7, the rubber compositions of each embodiment maintain good physical and mechanical properties, with tensile strength of 8-22 MPa and elongation at break of 260-530%. Comparing Examples 1-25 with Comparative Examples 1-3, Example 26 with Comparative Examples 4-6, Example 27 with Comparative Examples 7-9, Example 28 with Comparative Examples 10-12, and Example 29 with Comparative Examples 13-15, it can be seen that the rubber compositions of the embodiments with the addition of specific first and second compounds have better static and dynamic ozone aging resistance grades than the comparative examples. Specifically, the cracking grade of the embodiments after 144 hours of static ozone aging is 2b or higher, and the cracking grade after 144 hours of dynamic ozone aging is 2b or higher. This indicates that after the addition of specific first and second compounds, the rubber compositions of the present invention retain basic mechanical properties while also exhibiting excellent ozone aging resistance.

[0094] As can be seen from the results of Examples 1 to 10, as the mass ratio of the first compound and the second compound gradually decreases, the static ozone aging performance and dynamic ozone aging performance of the rubber composition first improves and then deteriorates. Further adjustment of the mass ratio of the two compounds (e.g., (70~99.9):(0.1~30), or further (95~99.5):(0.5~5)) can further improve the static ozone aging resistance and dynamic ozone aging resistance of the rubber composition.

[0095] As can be seen from the comparison of Example 4 with Comparative Example 1, Example 26 with Comparative Example 4, Example 27 with Comparative Example 7, Example 28 with Comparative Example 10, and Example 29 with Comparative Example 13, compared with the traditional antioxidant 6PPD, the first compound and the second compound only require a lower total amount, and the rubber composition can exhibit better crack resistance under the same ozone aging conditions, thereby effectively extending the service life of the rubber composition.

[0096] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A rubber composition, characterized in that, Based on 100 parts by weight of rubber, it contains 0.1 to 3 parts by weight of crosslinking agent, a first compound, and a second compound, wherein the total amount of the first compound and the second compound added is 0.1 to 10 parts by weight; The rubber refers to an elastomer formed by the polymerization of monomers containing dienes; The mass ratio of the first compound to the second compound is (50~99.95):(0.05~50). The first compound is at least one of the compounds with the structure shown in Formula I, and the second compound is at least one of the compounds with the structure shown in Formula II; Formula I In Formula I: R1 is C1~C 24 Alkyl or vinyl; R3, R4, and R5 are each independently hydrogen or C1-C6 alkyl groups; R2 and A - It is one of the following (a) to (b): (a) A - It pairs with the imidazolium cation via an ionic bond to form an imidazolium exosalt, where R2 is a C1-C6 alkyl group, and A... - For F - NO3 - HSO4 - Cl - RCOO - , RSO3 - ,Br - CF3SO3 - (C4H9O)2PO2 - H2PO4 - CF3COO - N(CN)2 - I - or OH - R is a C1 to C6 alkyl group; (b) A - It is covalently linked to R2 and then bonded to the imidazole ring via R2 to form an imidazole-onium inner salt, where R2 is a C1-C6 alkylene group. - It is a sulfonate group; Formula II In Formula II: R6 and R7 are each independently selected from hydrogen, C1-C6 alkyl, C2-C7 alkenyl, C6 ... 12 Aryl or C7~C 18 Aryl alkyl group, and at least one of R6 and R7 is hydrogen; R8, R9, R 10 Each is independently selected from hydrogen or C1 to C6 alkyl groups.

2. The rubber composition according to claim 1, characterized in that, The mass ratio of the first compound to the second compound is (70~99.9):(0.1~30).

3. The rubber composition according to claim 1, characterized in that, The rubber composition satisfies at least one of the following (1) to (8): (1) Based on 100 parts by weight of rubber, the amount of the crosslinking agent is 0.5 to 1.8 parts by weight; (2) Based on 100 parts by weight of rubber, the rubber composition further comprises 0.1 to 120 parts by weight of filler; (3) Based on 100 parts by weight of rubber, the rubber composition further comprises 0.5 to 15 parts by weight of a softener; (4) Based on 100 parts by weight of rubber, the rubber composition further comprises 1 to 10 parts by weight of activator; (5) Based on 100 parts by weight of rubber, the rubber composition further comprises 0.2 to 5 parts by weight of accelerator; (6) Based on 100 parts by weight of rubber, the rubber composition further comprises 0 to 5 parts by weight of tackifying resin; (7) Based on 100 parts by weight of rubber, the rubber composition further comprises 0 to 10 parts by weight of plasticizer; (8) Based on 100 parts by weight of rubber, the rubber composition further comprises 0 to 10 parts by weight of coupling agent.

4. The rubber composition according to claim 1, characterized in that, The diene includes at least one of butadiene, isoprene, 2-chloro-1,3-butadiene, dicyclopentadiene, or hexadiene.

5. The rubber composition according to claim 1, characterized in that, The rubber includes at least one of natural rubber, butadiene rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, ethylene propylene diene monomer (EPDM) rubber, isoprene / butadiene copolymer, isoprene / styrene copolymer, or isoprene / butadiene / styrene copolymer.

6. The rubber composition according to claim 1, characterized in that, The rubber composition satisfies at least one of the following (1) to (2): (1) The compound having the structure shown in Formula I is at least one of 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium methanesulfonate, 1-hexadecyl-3-methylimidazolium bromide, 1-sulfobutyl-3-methylimidazolium inner salt, 1-n-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium dibutyl phosphate, 1-vinyl-3-butylimidazolium chloride, 1-butyl-3-methylimidazolium dihydrogen phosphate, 1-butyl-2,3-dimethylimidazolium chloride, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium bromide, 1-hexadecyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium dicyandiamide, 1-butyl-3-methylimidazolium iodide or 1-butyl-3-methylimidazolium hydroxide; (2) The compound having the structure shown in Formula II is at least one of 1-methylimidazole, 1-ethylimidazole, 1-propylimidazole, 1-butylimidazole, 1-ethyl-2-methylimidazole, 1-methyl-2-ethylimidazole, 1-butyl-2-methylimidazole, 1-vinylimidazole, 1-allylimidazole, 1,2-dimethylimidazole, 1-benzylimidazole, 1-phenylimidazole, 2-methylimidazole or 4-methylimidazole.

7. A method for preparing the rubber composition according to any one of claims 1 to 6, characterized in that, Includes the following steps: First, the rubber is mixed with components other than the crosslinking agent and accelerator. Then, the crosslinking agent and accelerator are added and mixed again before vulcanization to obtain the rubber composition.

8. A rubber product, characterized in that, The rubber article comprises the rubber composition according to any one of claims 1 to 6.

9. The rubber product according to claim 8, characterized in that, The rubber products are tires, rubber shoes, sealing strips, sound insulation boards, or vibration damping pads.

10. The rubber product according to claim 9, characterized in that, The tire includes sidewall rubber or tread rubber.

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