p-Phenylenediamine compounds, their preparation methods and applications

Abstract

The present invention provides a p-phenylenediamine compound, a preparation method thereof and an application. The compound has a structure shown in formula I, wherein R 1 is a straight-chain or branched-chain alkyl group having 4 to 16 carbon atoms, and R 2 is a straight-chain or branched-chain alkyl group having 3 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a phenyl group or a phenyl group substituted with an alkyl group having 3 to 10 carbon atoms. The compound can provide better heat-oxygen fatigue aging and long-term protection performance than conventional anti-aging agents, as well as stronger discoloration resistance. The compound can be used as an additive in plastics, elastomers, lubricating oils, etc., and can delay the degradation trend caused by oxygen, ozone, repeated mechanical action, etc. during use.

Description

Technical Field

[0001] The present invention belongs to the field of anti-aging agents, and particularly relates to p-phenylenediamine compounds, their preparation methods and applications. Background Art

[0002] Currently, p-phenylenediamine compounds are commonly used as anti-aging agents in rubber products, especially in tires, including dialkyl p-phenylenediamine, alkylaryl p-phenylenediamine and diaryl p-phenylenediamine. The most widely used anti-aging agent is 6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine), and others include IPPD (N-isopropyl-N'-phenyl-p-phenylenediamine), 77PD (N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine), DTPD (a mixture of diphenyl p-phenylenediamine, bis(tolyl) p-phenylenediamine and phenyltolyl p-phenylenediamine), etc.

[0003] The widely used rubber anti-aging agent 6PPD has a relatively small molecular weight. During the use of rubber products or tires, the anti-aging agent quickly migrates to the surface, resulting in discoloration of the tire surface. The anti-aging agent DTPD is a diaryl p-phenylenediamine. As a recognized long-acting and after-effect anti-aging agent, its anti-aging performance is relatively persistent, but its compatibility with rubber is poor, and a large amount of use leads to blooming. In recent years, users have paid increasing attention to the anti-aging persistence and surface discoloration of tires. Therefore, there is an urgent need in this field for a compound with more long-lasting anti-aging protection efficacy and better color fastness than existing products. Summary of the Invention

[0004] The present invention designs and synthesizes a compound with the structure of formula I. This compound contains both a p-phenylenediamine structure that is good at scavenging free radicals and two long-chain alkyl groups to enhance its compatibility with rubber, and has a physical shielding effect, which can delay the oxidation and flex fatigue degradation of unsaturated rubber. The present invention finds that this compound can provide better heat-oxygen fatigue aging and long-term protection performance than conventional anti-aging agents, as well as stronger color fastness. This compound can be used as an additive in plastics, elastomers, lubricating oils, etc., and can delay the degradation trend caused by oxygen, ozone, repeated mechanical action, etc. during use.

[0005] Specifically, the present invention provides a compound of formula I:

[0006]

[0007] Wherein, R 1 is a straight-chain or branched-chain alkyl group with 4 to 16 carbon atoms, and R 2 is a straight-chain or branched-chain alkyl group with 3 to 10 carbon atoms, a cycloalkyl group with 3 to 10 carbon atoms, a phenyl group or a phenyl group substituted with an alkyl group with 3 to 10 carbon atoms.

[0008] In one or more embodiments, in the compound of formula I, R1 is n-butyl, tert-butyl, n-hexyl, iso-hexyl, tert-octyl, n-dodecyl, n-tetradecyl or n-hexadecyl.

[0009] In one or more embodiments, in the compound of formula I, R 1 is a straight-chain or branched-chain alkyl group having 4 to 12 carbon atoms.

[0010] In one or more embodiments, in the compound of formula I, R 1 is tert-butyl, tert-octyl or n-dodecyl.

[0011] In one or more embodiments, in the compound of formula I, R 2 is a branched-chain alkyl group having 3 to 10 carbon atoms.

[0012] In one or more embodiments, in the compound of formula I, R 2 is isopropyl, 1,3-dimethylbutyl, 1,4-dimethylpentyl, cyclohexyl or phenyl.

[0013] In one or more embodiments, in the compound of formula I, R 2 is a branched-chain alkyl group having 3 to 7 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms or phenyl.

[0014] In one or more embodiments, in the compound of formula I, R 2 is isopropyl, 1,3-dimethylbutyl, 1,4-dimethylpentyl or phenyl.

[0015] In one or more embodiments, the compound of formula I is selected from:

[0016]

[0017]

[0018] The present invention also provides a method for preparing the compound of formula I according to any one of the embodiments of the present invention, comprising:

[0019] (1) Reacting cyanuric chloride with a compound A represented by the following formula to obtain an intermediate M represented by the following formula:

[0020]

[0021] (2) Reacting the intermediate M with R 1 NH 2 to obtain the compound of formula I:

[0022]

[0023] wherein, R 1 and R 2As defined in any embodiment of the present invention.

[0024] In one or more embodiments, the method has one or more of the following features:

[0025] The amount of compound A added in step (1) is 100% - 120% of the amount of cyanuric chloride added in step (1);

[0026] Step (1) is carried out in the presence of an alkali solution; and

[0027] The reaction temperature of step (1) is -5 to 10 °C.

[0028] In one or more embodiments, the alkali solution is selected from one or more of sodium carbonate solution, sodium hydroxide solution, potassium carbonate solution, potassium hydroxide solution, triethylamine, triisopropylamine, N - isopropyldiethylamine, and N,N - diisopropylethylamine, etc., preferably selected from one or more of sodium carbonate solution, sodium hydroxide solution, potassium carbonate solution, and potassium hydroxide solution.

[0029] In one or more embodiments, compound A is selected from N - phenyl - p - phenylenediamine, N - isopropyl - p - phenylenediamine, N - cyclohexyl - p - phenylenediamine, N - (1,3 - dimethyl)butyl - p - phenylenediamine, and N - (1,4 - dimethyl)pentyl - p - phenylenediamine.

[0030] In one or more embodiments, the method has one or more of the following features:

[0031] The amount of R 1 NH 2 added in step (2) is 400% - 480% of the amount of intermediate M added in step (2); and

[0032] The reaction temperature of step (2) is 60 - 150 °C.

[0033] In one or more embodiments, R 1 NH 2 is n - butylamine, tert - butylamine, n - hexylamine, iso - hexylamine, tert - octylamine, dodecylamine, tetradecylamine, or hexadecylamine.

[0034] The present invention also provides a rubber composition, which contains the compound of formula I according to any embodiment of the present invention.

[0035] The present invention also provides a rubber product, which contains the rubber composition according to any embodiment of the present invention; preferably, the rubber product is a tire.

[0036] The present invention also provides the use of the compound of formula I according to any embodiment of the present invention in improving the antioxidant performance and / or discoloration resistance of rubber or rubber products; preferably, the rubber product is a tire. Description of the Drawings

[0037] Figure 1 For the tensile product retention rate of the vulcanized rubber sheets in Test Examples 1-4 before and after aging.

[0038] Figure 2 For the tear strength retention rate of the vulcanized rubber sheets in Test Examples 1-4 before and after aging.

[0039] Figure 3 Schematic diagram of the Lab color model for color difference evaluation. Detailed Description of the Invention

[0040] To enable those skilled in the art to understand the features and effects of the present invention, the following provides only a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art for the present invention. In case of conflict, the definition in this specification shall prevail.

[0041] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not in any way limit the scope of the present invention, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0042] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0043] In this article, for the sake of brevity of description, all possible combinations of all technical features in each embodiment or example are not described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered as the scope described in this specification.

[0044] In this article, alkyl refers to a straight-chain or branched-chain monovalent saturated hydrocarbon group, usually containing 1 to 16 carbon atoms (C1-C16 alkyl), such as containing 3 to 16 carbon atoms (C3-C16 alkyl). Examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, isohexyl, 1,3-dimethylbutyl, 1,4-dimethylpentyl, tert-octyl, n-dodecyl, n-tetradecyl, or n-hexadecyl.

[0045] In this text, a cycloalkyl group refers to a monovalent saturated hydrocarbon ring, usually containing 3 to 10 carbon atoms (C3-C10 cycloalkyl group), such as containing 3 to 8 carbon atoms (C3-C8 cycloalkyl group). Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and adamantyl. In this text, the cycloalkyl group may optionally be substituted by an alkyl group, and the number of alkyl substituents on the cycloalkyl group can be 1 or 2.

[0046] The present invention discovers that the compound with the structure shown in Formula I below contains both a p-phenylenediamine structure that is good at scavenging free radicals and two long-chain alkyl groups that enhance the compatibility with rubber, and has a physical shielding effect mainly brought by the long-chain alkyl groups, which has a delaying effect on the oxidation and flex fatigue deterioration of unsaturated rubber, and can provide better heat-oxygen fatigue aging and long-term protection performance than conventional anti-aging agents, as well as stronger discoloration resistance:

[0047]

[0048] Wherein, R 1 is a straight-chain or branched-chain alkyl group with 4 to 16 carbon atoms, and R 2 is a straight-chain or branched-chain alkyl group with 3 to 10 carbon atoms, a C3-C10 cycloalkyl group, a phenyl group, or a phenyl group substituted by a C3-C10 alkyl group.

[0049] In certain embodiments, in the compound of Formula I, R 1 is n-butyl, tert-butyl, n-hexyl, isohexyl, tert-octyl, n-dodecyl, n-tetradecyl, or n-hexadecyl.

[0050] In certain embodiments, in the compound of Formula I, R 1 is a straight-chain or branched-chain alkyl group with 4 to 12 carbon atoms, such as including but not limited to tert-butyl, tert-octyl, or n-dodecyl. In some embodiments, in the compound of Formula I, R 1 is a branched-chain alkyl group with 4 to 8 carbon atoms, such as tert-butyl or tert-octyl.

[0051] In certain embodiments, in the compound of Formula I, R 2 is a branched-chain alkyl group with 3 to 10 carbon atoms.

[0052] In certain embodiments, in the compound of Formula I, R 2 is isopropyl, 1,3-dimethylbutyl, 1,4-dimethylpentyl, cyclohexyl, or phenyl.

[0053] In certain embodiments, in the compound of Formula I, R 2 is a branched-chain alkyl group with 3 to 7 carbon atoms, a C3-C7 cycloalkyl group, or a phenyl group. In certain embodiments, in the compound of Formula I, R 2is a branched alkyl group having 3 to 7 carbon atoms or a phenyl group, for example, including but not limited to isopropyl, 1,3-dimethylbutyl, 1,4-dimethylpentyl or phenyl group. In some embodiments, in the compound of formula I, R 2 is a branched alkyl group having 3 to 7 carbon atoms, for example isopropyl, 1,3-dimethylbutyl or 1,4-dimethylpentyl. In some embodiments, in the compound of formula I, R 2 is isopropyl. In some embodiments, in the compound of formula I, R 2 is 1,3-dimethylbutyl or 1,4-dimethylpentyl.

[0054] The present invention has found that generally, in the compound of formula I, R 1 , R 2 the longer the chain, the better the flexibility and the higher the retention rate of tear strength. Therefore, in some preferred embodiments, in the compound of formula I, R 1 is a straight-chain or branched alkyl group having 8 to 12 carbon atoms, such as tert-octyl or n-dodecyl; and / or, R 2 is a branched alkyl group having 6 to 7 carbon atoms, such as 1,3-dimethylbutyl or 1,4-dimethylpentyl.

[0055] In certain embodiments, the compound of formula I is selected from:

[0056]

[0057]

[0058] In some embodiments, the compound of formula I is selected from:

[0059]

[0060]

[0061] The method for preparing the compound of formula I according to the present invention includes:

[0062] (1) Reacting cyanuric chloride with a compound A represented by the following formula to obtain an intermediate M represented by the following formula, wherein R 2 is a straight-chain or branched alkyl group having 3 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a phenyl group or a phenyl group substituted with a C3-C10 alkyl group:

[0063]

[0064] (2) Reacting the intermediate M with R 1 NH 2 to obtain the compound of formula I, wherein R 1 is a straight-chain or branched alkyl group having 4 to 16 carbon atoms:

[0065]

[0066] Among them, the preferred R in compound A 2 and R 1 NH 2 The preferred R in 1 may be as described in any embodiment herein.

[0067] In step (1), cyanuric chloride (TCT) and compound A (N-R 2 p-phenylenediamine, such as N-alkyl p-phenylenediamine or N-aryl p-phenylenediamine) are reacted to prepare intermediate M. In step (1), it is preferred to use an excess of compound A. Relative to the added TCT, the added compound A is preferably in an excess of no more than 20%, that is, the amount of substance of the added compound A is preferably 100% to 120% of the amount of substance of the added TCT. In some embodiments, relative to the added TCT, the added compound A is in an excess of 10% to 20%, that is, the amount of substance of the added compound A is 110% to 120% of the amount of substance of the added TCT. It can be understood that herein, a certain raw material X being in an excess of a certain percentage value relative to another raw material Y means the percentage value by which the amount of substance of the added raw material X exceeds the amount of substance of raw material X theoretically required to exactly react with the added raw material Y (or the substance generated by raw material Y in the reaction).

[0068] In some embodiments, the compound A used in step (1) is selected from N-phenyl p-phenylenediamine, N-isopropyl p-phenylenediamine, N-cyclohexyl p-phenylenediamine, N-(1,3-dimethyl)butyl p-phenylenediamine, or N-(1,4-dimethyl)pentyl p-phenylenediamine.

[0069] In step (1), an alkali solution is used as an acid-binding agent to neutralize the HCl generated in the reaction, that is, the reaction in step (1) is carried out in the presence of an alkali solution. The alkali solution applicable to the present invention is not particularly limited. For example, it may be one or more of a sodium carbonate solution, a sodium hydroxide solution, a potassium carbonate solution, a potassium hydroxide solution, triethylamine, triisopropylamine, N-isopropyldiethylamine, and N,N-diisopropylethylamine, etc. It can be understood that herein, the sodium carbonate solution, the sodium hydroxide solution, the potassium carbonate solution, and the potassium hydroxide solution respectively refer to the aqueous solutions of sodium carbonate, sodium hydroxide, potassium carbonate, and potassium hydroxide. In some embodiments, the alkali solution is one or more selected from a sodium carbonate solution, a sodium hydroxide solution, a potassium carbonate solution, and a potassium hydroxide solution. An excess of the alkali solution can be added in step (1). For example, the alkali in the alkali solution can be in an excess of less than 20% or less than 10% relative to TCT. In the present invention, when an aqueous solution of an inorganic alkali (such as a sodium carbonate solution, a sodium hydroxide solution, a potassium carbonate solution, and a potassium hydroxide solution) is used as the alkali solution, the concentration of the alkali solution is usually 20 wt% to 50 wt%.

[0070] In the present invention, the reactions of steps (1) and (2) are carried out in a non-polar solvent. It should be understood that herein, non-polar solvents include non-polar solvents and solvents with relatively weak polarity. The non-polar solvents applicable to the present invention can be selected from one or more of toluene, xylene, trimethylbenzene, chlorobenzene, methylcyclohexane, dichlorobenzene, trichlorobenzene, dimethylcyclohexane, and trimethylcyclohexane. In some embodiments, toluene, xylene, or a mixture thereof is used as the solvent in the present invention.

[0071] The reaction temperature of step (1) is controlled at -5 to 10 °C. Preferably, in step (1), compound A is added first, and then the alkali solution is added. Preferably, compound A is added at -5 to 0 °C. Preferably, the alkali solution is added and the reaction is continued at 0 to 10 °C. Preferably, compound A and the alkali solution are added slowly. Preferably, based on the amount of substance of the base in compound A or the alkali solution, the addition rate of compound A and the alkali solution does not exceed 0.015 mol / minute, for example, between 0.01 mol / minute and 0.015 mol / minute. For example, when 0.3 to 0.4 mol of compound A and the alkali solution are used, compound A and the alkali solution can be added separately over about 30 minutes. In a preferred embodiment, in step (1), compound A is slowly added to the mixture of TCT and the solvent at -5 to 0 °C. After addition, the reaction system is heated to 0 to 10 °C, and then the alkali solution is slowly added and the reaction is continued. If necessary, compound A can be dissolved in the solvent and then added to the mixture of TCT and the solvent. In step (1), after adding the alkali solution, it is preferably continued to react for 2 to 3 hours. After the reaction is completed, conventional purification can be carried out, for example, phase separation, washing with water, and drying can be carried out to obtain a solution of intermediate M.

[0072] In step (2), intermediate M reacts with primary alkylamine (R 1 NH 2 ) to prepare compound I. In step (2), an excess of R 1 NH 2 is used as an acid-binding agent. Relative to the added intermediate M, the added R 1 NH 2 is preferably not more than 120% in excess, that is, the amount of substance of the added R 1 NH 2 is preferably not more than 480% of the amount of substance of the added intermediate M. In some embodiments, relative to the added intermediate M, the added R 1 NH 2 is in excess by 100 to 120%, that is, the amount of substance of the added R 1 NH 2 is 400 to 480% of the amount of substance of the added intermediate M.

[0073] In some embodiments, the R used in step (2)1 NH 2 Selected from n-butylamine, tert-butylamine, n-hexylamine, isohexylamine, tert-octylamine, dodecylamine (n-dodecyl primary amine), tetradecylamine (n-tetradecyl primary amine), or hexadecylamine (n-hexadecyl primary amine).

[0074] The reaction temperature in step (2) is preferably 60 - 150 °C. Whether the reaction is complete can be judged by sampling to detect whether intermediate M still exists. The reaction time in step (2) is usually 3 - 6 hours. The reaction in step (2) is preferably carried out in a closed container, for example, it can be carried out in an autoclave. After the reaction in step (2) is completed, conventional purification can be carried out, such as neutralizing with an alkali solution, washing with water, and distilling the organic phase to recover the solvent and the excess R 1 NH 2 , to obtain the target compound (Compound of Formula I).

[0075] The Compound of Formula I of the present invention can provide better heat-oxygen fatigue aging and long-term protection performance, as well as stronger discoloration resistance for the rubber composition than conventional anti-aging agents. Therefore, the present invention also provides a rubber composition, which contains one or more of the Compounds of Formula I described herein.

[0076] The raw materials of the rubber composition generally include diene elastomers, reinforcing fillers, anti-aging agents, and crosslinking agents. In the rubber composition of the present invention, the amounts of the diene elastomer, reinforcing filler, anti-aging agent, and crosslinking agent can be conventional amounts in the art. Based on 100 parts by mass of the diene elastomer, the amount of the Compound of Formula I in the rubber composition can be 0.1 - 5 parts by mass, for example, 0.5 - 5 parts by mass, 2 - 3 parts by mass, or about 2.5 parts by mass. Herein, the rubber composition includes unvulcanized rubber and vulcanized rubber. The unvulcanized rubber can be made into vulcanized rubber through vulcanization (curing).

[0077] Diene elastomers refer to elastomers whose monomers contain dienes (such as butadiene, isoprene). The diene elastomers suitable for the present invention can be various diene elastomers known in the art, including but not limited to one or more selected from natural rubber (NR), cis-butadiene rubber (BR), isoprene rubber, styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), isoprene / butadiene copolymer, isoprene / styrene copolymer, and isoprene / butadiene / styrene copolymer. In certain embodiments, in the rubber composition of the present invention, the diene elastomer consists of natural rubber (such as SCR5) and cis-butadiene rubber (such as BR9000); the mass ratio of natural rubber to cis-butadiene rubber is not particularly limited, for example, it is 1:9 to 9:1, 2:8 to 8:2, 3:7 to 7:3, 4:6 to 6:4, or about 1:1.

[0078] The reinforcing filler can be a reinforcing filler conventionally used in rubber, including but not limited to one or more selected from carbon black, titanium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, clay, and talc. In some embodiments, the reinforcing filler in the rubber composition of the present invention is carbon black. The amount of the reinforcing filler can be 40 - 60 parts by mass of the reinforcing filler per 100 parts by mass of the diene elastomer.

[0079] The crosslinking agent can be sulfur. The amount of the crosslinking agent can be 1 - 3 parts by mass of the crosslinking agent per 100 parts by mass of the diene elastomer.

[0080] In addition to containing the compound of formula I of the present invention, the rubber composition of the present invention can also optionally contain other antioxidants known in the art (such as 6PPD, IPPD, 77PD, DTPD, etc.). When the rubber composition of the present invention contains the compound of formula I of the present invention and other antioxidants, based on 100 parts by mass of the diene elastomer, in the rubber composition, the total amount of the compound of formula I and other antioxidants is usually 0.1 - 5 parts by mass, such as 0.5 - 5 parts by mass, 2 - 3 parts by mass, etc.; the dosage ratio between the compound of formula I and other antioxidants can be determined according to performance requirements.

[0081] The raw materials of the rubber composition can also include other components commonly used in rubber, including but not limited to auxiliaries and accelerators, etc. The dosages of the auxiliaries and accelerators can be conventional dosages in the art.

[0082] The auxiliaries can include softeners used to improve processability. The softeners can be petroleum softeners such as aromatic oil, processing oil, lubricating oil, paraffin wax, liquid paraffin, petroleum pitch, and petrolatum, etc., or can be fatty oil softeners such as castor oil, linseed oil, rapeseed oil, coconut oil, waxes (such as beeswax, carnauba wax, and lanolin), tall oil, linoleic acid, palmitic acid, stearic acid, and lauric acid, etc. The auxiliaries can also include activators, such as zinc oxide, which can play roles in accelerating the vulcanization rate, improving the thermal conductivity, abrasion resistance, tear resistance, etc. of the rubber. Usually, a total of 5 - 20 parts by mass of auxiliaries are used per 100 parts by mass of the diene elastomer. For example, 2 - 8 parts by mass of aromatic oil, 2 - 8 parts by mass of zinc oxide, and 1 - 4 parts by mass of stearic acid can be used.

[0083] The accelerator is usually a vulcanization accelerator and can be at least one of sulfonamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamate, aldehyde - amine, aldehyde - ammonia, imidazoline, and xanthate vulcanization accelerators. For example, the accelerator can be accelerator NS (N - tert - butyl - 2 - benzothiazole sulfenamide). Usually, 0.5 - 1.5 parts by mass of the accelerator are used per 100 parts by mass of the diene elastomer.

[0084] In addition, when needed, plasticizers such as 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), and DCHP (dicyclohexyl phthalate) can also be used in the rubber composition. The amount of the plasticizer is a conventional amount in the art.

[0085] The unvulcanized rubber of the present invention can be prepared by a conventional rubber mixing method, for example, by a two-stage mixing method: mixing in a one-stage internal mixer, mixing a diene elastomer, a reinforcing filler, an additive, and an antioxidant, with a discharge temperature above 110°C; mixing in a two-stage open mill, mixing the rubber obtained in the one-stage with a crosslinking agent and an accelerator. Generally, first add the diene elastomer to a thermo-mechanical mixer (such as an internal mixer), knead for a certain time, then add the reinforcing filler, additive, and antioxidant, and continue kneading until evenly mixed. The reinforcing filler, additive, and antioxidant can be added in batches, and the temperature during kneading is controlled between 110°C and 190°C, preferably between 150°C and 160°C; then, cool the mixture to below 100°C, add the crosslinking agent and the accelerator, and knead again. The temperature during kneading is controlled below 110°C, such as about 70°C, to obtain the unvulcanized rubber.

[0086] The unvulcanized rubber of the present invention can be vulcanized by a conventional vulcanization method to obtain a vulcanized rubber; the vulcanization temperature is usually 130°C - 200°C, such as about 145°C; the vulcanization time depends on the vulcanization temperature, vulcanization system, and vulcanization kinetics, and is usually 15 - 60 minutes, such as about 30 minutes. Before vulcanization, the unvulcanized rubber obtained by kneading can be conventionally sheeted.

[0087] The compound I and the rubber composition of the present invention are used in rubber products, especially rubber tires. Compared with conventional antioxidants, they can endow rubber products or rubber tires with better heat-oxygen fatigue aging and long-term protection performance, as well as stronger discoloration resistance. Therefore, the present invention also provides a rubber product containing the rubber composition described herein. The rubber product can be a tire, rubber shoes, a sealing strip, a sound insulation board, a vibration damping pad, etc. In certain embodiments, the rubber product is a tire, such as the tread, belt layer, and sidewall of a tire. The belt layer of the tire, in addition to the rubber composition of the present invention, can also contain reinforcing materials conventionally used in the art. The present invention also provides the use of the compound of formula I of the present invention in improving the antioxidant performance and / or discoloration resistance of rubber.

[0088] The present invention will be described below by way of specific embodiments. It should be understood that these embodiments are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents, and materials used in the embodiments are conventional methods, reagents, and materials in the art unless otherwise specified. The starting compounds in the preparation examples can be obtained through commercial channels.

[0089] Example 1: 2-(4-Isopropylamino)aniline-4,6-di-tert-butylamine-1,3,5-triazine (Compound I-1)

[0090]

[0091] (1) 60 g of cyanuric chloride (TCT) (0.32 mol) and 400 ml of xylene were added to a 1 L three-necked flask. A toluene solution of 43 g of 4-isopropylaminoaniline (0.32 mol of 4-isopropylaminoaniline dissolved in 100 mL of toluene, added dropwise over about 30 min) was slowly added dropwise under a cooling environment of -5°C. After the addition, the reaction system was heated to 10°C, and an aqueous NaOH solution (13 g dissolved in 40 ml of water, added dropwise over 30 min) was slowly added dropwise. The reaction was continued with stirring for 2 hours. After completion, the reaction system was separated into layers, the aqueous phase was separated, the organic phase was washed three times with water, and then dried over 6 g of anhydrous sodium sulfate and filtered to obtain an intermediate solution;

[0092] (2) The intermediate solution was added to a 1 L autoclave, 92.2 g (1.28 mol) of tert-butylamine was added, and the mixture was heated to 70°C with stirring for 4 h. The reaction mixture was sampled for liquid phase detection. When no intermediate was detected, the temperature was lowered; an NaOH solution (26 g dissolved in 80 g of water) was added, and the mixture was stirred until the solid dissolved. After standing for separation, the aqueous phase was separated, the organic phase was washed three times with water, and then the light components were distilled off under reduced pressure. The residual liquid was cooled and solidified to obtain the target product (Compound I-1).

[0093] 1 H-NMR (300 MHz, CDCl 3 ) δ 7.19 - 7.17 (m, 2H), 6.57 (s, 1H), 6.47 (d, J = 6 Hz, 2H), 4.93 (s, 2H), 3.58 - 3.46 (m, 1H), 1.34 (s, 18H), 1.12 (d, J = 6 Hz, 6H).

[0094] Example 2: 2-(4-Anilino)aniline-4,6-di-tert-butylamine-1,3,5-triazine (Compound I-2)

[0095]

[0096] (1) Add 60 g of TCT (0.32 mol) and 400 ml of xylene to a 1 L three-necked flask. Slowly drip a toluene solution of 64.4 g of 4-anilinophenylamine (0.35 mol of 4-anilinophenylamine dissolved in 120 mL of toluene, completed in about 30 min) under a cooling environment of -5 °C. After the addition, raise the temperature of the reaction system to 10 °C, and slowly drip an aqueous NaOH solution (13 g dissolved in 40 ml of water, completed in 30 min). Continue to stir the reaction for 3 hours. After completion, let it stand for liquid separation, separate the aqueous phase, wash the organic phase three times with water, then add 6 g of anhydrous sodium sulfate for drying and filter to obtain an intermediate solution;

[0097] (2) Add the intermediate solution to a 1 L autoclave, add 92.2 g (1.28 mol) of tert-butylamine, close it and raise the temperature to 70 °C for reaction for 4 h. Take a sample for liquid-phase detection. When no intermediate can be detected, lower the temperature; add an NaOH solution (26 g dissolved in 80 g of water), stir until the solid dissolves, let it stand for liquid separation, separate the aqueous phase, wash the organic phase three times with water, then distill off the light components under reduced pressure, and the residual liquid is cooled and solidified to obtain the target product (Compound I-2).

[0098] 1 H-NMR (300 MHz, CDCl 3 ) δ7.45 - 7.38 (m, 2H), 7.33 - 7.23 (m, 2H), 7.14 - 6.99 (m, 6H), 6.97 - 6.86 (m, 1H), 5.70 - 5.64 (m, 2H), 1.46 (s, 18H).

[0099] Example 3: 2-(4-(1,3-Dimethyl)butylamino)aniline-4,6-ditert-butylamine-1,3,5-triazine (Compound I-3)

[0100]

[0101] (1) Add 60 g of TCT (0.32 mol) and 400 ml of xylene to a 1 L three-necked flask. Slowly drip a toluene solution of 67.2 g of 4-(1,3-dimethyl)butylamino-aniline (0.35 mol of 4-(1,3-dimethyl)butylamino-aniline dissolved in 80 mL of toluene, completed in about 30 min) under a cooling environment of -5 °C. After the addition, raise the temperature of the reaction system to 10 °C, and slowly drip an aqueous NaOH solution (13 g dissolved in 40 ml of water, completed in 30 min). Continue to stir the reaction for 2 hours. After completion, let it stand for liquid separation, separate the aqueous phase, wash the organic phase three times with water, then add 4 g of anhydrous sodium sulfate for drying and filter to obtain an intermediate solution;

[0102] (2) Add the intermediate solution to a 1L autoclave, add 92.2 g (1.28 mol) of tert-butylamine, close it and heat up to 70 °C for reaction for 4 h. Take a sample for liquid-phase detection. When the intermediate cannot be detected, cool down the temperature; add NaOH solution (26 g dissolved in 80 g of water), stir until the solid dissolves, let it stand for layering, separate the aqueous phase, wash the organic phase three times with water, and then distill off the light components under reduced pressure. The residual liquid is cooled and solidified to obtain the target product (Compound I-3).

[0103] 1 H-NMR(300MHz,CDCl 3 )δ7.19-7.15(m,2H),6.77(s,1H),6.46(d,J=6Hz,2H),4.82(s,2H),3.42-3.36(m,1H),1.71-1.63(m,1H),1.32(s,18H),1.18-1.12(m,2H),1.06(d,J=6Hz,3H),0.87-0.82(m,6H).

[0104] Example 4: 2-(4-(1,4-Dimethyl)pentylamino)aniline-4,6-di-tert-butylamine-1,3,5-triazine (Compound I-4)

[0105]

[0106] (1) Add 60 g of TCT (0.32 mol) and 400 ml of xylene to a 1L three-necked flask. Slowly dropwise add a toluene solution of 72.1 g of 4-(1,4-dimethyl)pentylamino-aniline (0.35 mol of 4-(1,4-dimethyl)pentylamino-aniline dissolved in 80 mL of toluene, about 30 min to finish dropping)

[0107] in a cooling environment at -5 °C. After dropping, raise the temperature of the reaction system to 10 °C, slowly dropwise add an aqueous NaOH solution (13 g dissolved in 40 ml of water, added dropwise in 30 min), continue to stir the reaction for 2 hours, let it stand for layering after completion, separate the aqueous phase, wash the organic phase three times with water, then add 8 g of anhydrous sodium sulfate for drying and filter to obtain the intermediate solution;

[0108] (2) Add the intermediate solution to a 1L autoclave, add 92.2 g (1.28 mol) of tert-butylamine, close it and heat up to 70 °C for reaction for 4 h. Take a sample for liquid-phase detection. When the intermediate cannot be detected, cool down the temperature; add NaOH solution (26 g dissolved in 80 g of water), stir until the solid dissolves, let it stand for layering, separate the aqueous phase, wash the organic phase three times with water, and then distill off the light components under reduced pressure. The residual liquid is cooled and solidified to obtain the target product (Compound I-4).

[0109] 1 H-NMR(300MHz,CDCl3 )δ7.19-7.16(m,2H),6.55(s,1H),6.45(d,J=6Hz,2H),4.88(s,2H),3.33-3.29(m,1H),1. 54-1.42(m,3H),1.35(s,18H),1.23-1.14(m,2H),1.08(d,J=6Hz,3H),0.83-0.80(m,6H).

[0110] Example 5: 2-(4-isopropylamino)aniline-4,6-di-tert-octylamine-1,3,5-triazine (Compound I-5)

[0111]

[0112] (1) 60 g of TCT (0.32 mol) and 400 ml of xylene were added to a 1 L three-necked flask, and a toluene solution of 43 g of 4-isopropylaminoaniline (0.32 mol of 4-isopropylaminoaniline was dissolved in 100 mL of toluene, and the addition was completed over about 30 minutes) was slowly added dropwise under a cooling environment of -5°C. After the addition was completed, the reaction system was heated to 10°C, and an aqueous solution of NaOH (13 g was dissolved in 40 ml of water, and the addition was completed over 30 minutes) was slowly added dropwise. The reaction was stirred for 2 hours. After the reaction was completed, the reaction system was separated into layers, the aqueous phase was separated, the organic phase was washed with water three times, and then 6 g of anhydrous sodium sulfate was added, dried, and filtered to obtain an intermediate solution;

[0113] (2) The intermediate solution was added to a 1L four-necked bottle, and 192g (1.28mol) of tert-octylamine was added. The temperature was raised to 90-100°C for reaction for 4h. The liquid phase was sampled for detection. When no intermediate could be detected, the temperature was lowered. NaOH solution (26g dissolved in 80g water) was added and stirred until the solid was dissolved. The mixture was allowed to stand for stratification. The aqueous phase was separated. The organic phase was washed with water three times and then distilled under reduced pressure to remove the light component. The residual liquid was cooled and solidified to obtain the target product (Compound I-5).

[0114] 1 H-NMR (300MHz, CDCl 3 )δ7.30-7.27(m,2H),6.56(d,J=6Hz,2H),4.98(s,2H),3.77-3.71(m,2H), 2.20(s,1H),1.90(s,4H),1.49(s,12H),1.28-1.21(m,6H),1.04(s,18H).

[0115] Example 6: 2-(4-anilino)aniline-4,6-di-tert-octylamine-1,3,5-triazine (Compound I-6)

[0116]

[0117] (1) Add 60 g of TCT (0.32 mol) and 400 ml of xylene into a 1 L three-necked flask. Slowly dropwise add a toluene solution of 64.4 g of 4-anilinophenylamine (0.35 mol of 4-anilinophenylamine dissolved in 120 mL of toluene, and the addition is completed in about 30 min) under a cooling environment of -5°C. After the addition, raise the temperature of the reaction system to 10°C, and slowly dropwise add an aqueous NaOH solution (13 g dissolved in 40 ml of water, and the addition is completed in 30 min). Continue to stir the reaction for 2 hours. After completion, let it stand for liquid separation, separate the aqueous phase, wash the organic phase three times with water, then add 6 g of anhydrous sodium sulfate for drying and filter to obtain an intermediate solution;

[0118] (2) Add the intermediate solution into a 1 L four-necked flask, add 192 g (1.28 mol) of tert-octylamine, raise the temperature to 110 - 120°C and react for 4 h. Take a sample for liquid-phase detection. When no intermediate can be detected, lower the temperature; add an NaOH solution (26 g dissolved in 80 g of water), stir until the solid dissolves, let it stand for liquid separation, separate the aqueous phase, wash the organic phase three times with water, then distill off the light components under reduced pressure. The residual liquid is cooled and solidified to obtain the target product (Compound I-6).

[0119] 1 H-HMR(300MHz, CDCl 3 ) δ 7.44 - 7.36(m, 2H), 7.34 - 7.21(m, 3H), 7.12 - 6.99(m, 4H), 6.97 - 6.88(m, 1H), 5.68 - 5.66(m, 2H) 1.51(s, 12H), 1.07 - 1.05(m, 4H), 1.03(s, 18H).

[0120] Example 7: 2-(4-(1,3-dimethyl)butylamino)aniline-4,6-di-tert-octylamine-1,3,5-triazine (Compound I-7)

[0121]

[0122] (1) Add 60 g of TCT (0.32 mol) and 400 ml of xylene into a 1 L three-necked flask. Slowly dropwise add a toluene solution of 67.2 g of 4-(1,3-dimethyl)butylamino-aniline (0.35 mol of 4-(1,3-dimethyl)butylamino-aniline dissolved in 80 mL of toluene, and the addition is completed in about 30 min) under a cooling environment of -5°C. After the addition, raise the temperature of the reaction system to 10°C, and slowly dropwise add an aqueous NaOH solution (13 g dissolved in 40 ml of water, and the addition is completed in 30 min). Continue to stir the reaction for 2 hours. After completion, let it stand for liquid separation, separate the aqueous phase, wash the organic phase three times with water, then add 6 g of anhydrous sodium sulfate for drying and filter to obtain an intermediate solution;

[0123] (2) Add the intermediate solution into a 1L four-necked flask, add 192 g (1.28 mol) of tert-octylamine, heat up to 100 - 110 °C and react for 4 h. Take a sample for liquid-phase detection. When no intermediate can be detected, cool down the temperature; add NaOH solution (26 g dissolved in 80 g of water), stir until the solid dissolves, let it stand for layering, separate the aqueous phase, wash the organic phase three times with water, then distill off the light components under reduced pressure. The residual liquid is cooled and solidified to obtain the target product (Compound I-7).

[0124] 1 H-NMR(300MHz,CDCl 3 )δ7.20 - 7.15(m,2H),6.45(d,J=6Hz,2H),4.84(s,2H),3.34 - 3.26(m,1H),1.80(s,3H),1.51 - 1.43(m,1H),1.38(s,12H),1.23 - 1.15(m,2H),1.09(d,J=6Hz,4H),0.92(s,18H)0.82 - 0.81(m,6H).

[0125] Example 8: 2-(4-(1,4-dimethyl)pentylamino)aniline-4,6-di-tert-octylamine-1,3,5-triazine (Compound I-8)

[0126]

[0127] (1) Add 60 g of TCT (0.32 mol) and 400 ml of xylene into a 1L three-necked flask. Slowly dropwise add a toluene solution of 72.1 g of 4-(1,4-dimethyl)pentylamino-aniline (0.35 mol of 4-(1,4-dimethyl)pentylamine is dissolved in 80 mL of toluene, and the addition is completed in about 30 min) under a cooling environment of -5 °C. After the addition, heat up the reaction system to 10 °C, slowly dropwise add an aqueous NaOH solution (13 g dissolved in 40 ml of water, and the addition is completed in 30 min). Continue to stir the reaction for 2 hours. After completion, let it stand for layering, separate the aqueous phase, wash the organic phase three times with water, then add 6 g of anhydrous sodium sulfate for drying and filter to obtain the intermediate solution;

[0128] (2) Add the intermediate solution into a 1L four-necked flask, add 192 g (1.28 mol) of tert-octylamine, heat up to 100 - 110 °C and react for 4 h. Take a sample for liquid-phase detection. When no intermediate can be detected, cool down the temperature; add NaOH solution (26 g dissolved in 80 g of water), stir until the solid dissolves, let it stand for layering, separate the aqueous phase, wash the organic phase three times with water, then distill off the light components under reduced pressure. The residual liquid is cooled and solidified to obtain the target product (Compound I-8).

[0129] 1 H-NMR(300MHz,CDCl 3) δ 7.20 (s, 2H), 7.15 (s, 1H), 6.46 (d, J = 6 Hz, 2H), 4.90 (s, 2H), 3.45 - 3.40 (m, 1H), 1.80 (s, 4H), 1.73 - 1.63 (m, 2H), 1.38 (s, 12H), 1.20 - 1.14 (m, 2H), 1.07 (d, J = 6 Hz, 4H), 0.92 (s, 18H) 0.88 - 0.84 (m, 6H).

[0130] Example 9: 2-(4-Isopropylamino)aniline-4,6-bis(dodecylamine)-1,3,5-triazine (Compound I-9)

[0131]

[0132] (1) 60 g of TCT (0.32 mol) and 400 ml of xylene were added to a 1 L three-necked flask. A toluene solution of 43 g of 4-isopropylaminoaniline (0.32 mol of 4-isopropylaminoaniline dissolved in 100 mL of toluene, added dropwise over about 30 min) was slowly added dropwise under a cooling environment of -5°C. After the addition, the reaction system was heated to 10°C, and an aqueous NaOH solution (13 g dissolved in 40 ml of water, added dropwise over 30 min) was slowly added dropwise. The reaction was continued with stirring for 2 hours. After completion, the reaction system was separated into layers, the aqueous phase was separated, the organic phase was washed three times with water, and then dried over 6 g of anhydrous sodium sulfate and filtered to obtain an intermediate solution;

[0133] (2) The intermediate solution was added to a 1 L reaction kettle, 235.5 g (1.28 mol) of dodecylamine was added, and the temperature was raised to 120 - 130°C for reaction for 4 h. The liquid phase was sampled for detection. When no intermediate could be detected, the temperature was lowered; an NaOH solution (26 g dissolved in 80 g of water) was added, stirred until the solid dissolved, allowed to stand and separate into layers, the aqueous phase was separated, the organic phase was washed three times with water, and then the light components were distilled off under reduced pressure. The residual liquid was cooled and solidified to obtain the target product (Compound I-9).

[0134] 1 H-NMR (300 MHz, DMSO-d 6 ) δ 8.43 - 8.17 (m, 1H), 7.39 (d, J = 18 Hz, 2H), 6.53 (d, J = 18 Hz, 2H), 4.90 (s, 1H), 3.46 (s, 1H), 3.19 (s, 4H), 1.51 (s, 4H), 1.25 (s, 40H), 1.11 (d, J = 6 Hz, 6H), 0.87 - 0.84 (m, 6H).

[0135] Example 10: 2-(4-Anilino)aniline-4,6-bis(dodecylamine)-1,3,5-triazine (Compound I-10)

[0136]

[0137] (1) Add 60 g of TCT (0.32 mol) and 400 ml of xylene into a 1 L three-necked flask. Slowly dropwise add a toluene solution of 64.4 g of 4-aminophenylamine (0.35 mol of 4-aminophenylamine dissolved in 120 mL of toluene, and the dropping is completed in about 30 min) under a cooling environment of -5 °C. After the dropping is completed, raise the temperature of the reaction system to 10 °C, and slowly dropwise add an aqueous NaOH solution (13 g dissolved in 40 ml of water, and the dropping is completed in 30 min). Continue to stir the reaction for 2 hours. After the reaction is completed, the reaction system is layered. Separate the aqueous phase. Wash the organic phase three times with water, then add 6 g of anhydrous sodium sulfate for drying and filter to obtain an intermediate solution;

[0138] (2) Add the intermediate solution into a 1 L reaction kettle, add 235.5 g (1.28 mol) of dodecylamine, raise the temperature to 130 - 140 °C and react for 4 h. Take a sample for liquid phase detection. When the intermediate cannot be detected, lower the temperature; add an NaOH solution (26 g dissolved in 80 g of water), stir until the solid is dissolved, let it stand for layering, separate the aqueous phase. Wash the organic phase three times with water and then distill off the light components under reduced pressure. The residual liquid is cooled and solidified to obtain the target product (Compound I-10).

[0139] 1 H-HMR(300MHz, CDCl 3 ) δ 7.52 - 7.50 (m, 2H), 7.32 - 7.22 (m, 2H), 7.1 - 6.97 (m, 4H), 6.92 - 6.85 (m, 1H), 5.67 - 5.67 (m, 2H), 5.04 - 5.08 (m, 2H), 3.39 (s, 4H), 1.28 (s, 36H), 0.95 - 0.86 (m, 10H).

[0140] Example 11: 2-(4-(1,3-dimethyl)butylamino)aniline-4,6-bis(dodecylamine)-1,3,5-triazine (Compound I-11)

[0141]

[0142] (1) Add 60 g of TCT (0.32 mol) and 400 ml of xylene to a 1 L three-necked flask. Slowly dropwise add a toluene solution of 67.2 g of 4-(1,3-dimethyl)butylamino-aniline (0.35 mol of 4-(1,3-dimethyl)butylamino-aniline dissolved in 80 mL of toluene, completed dropwise addition in about 30 min) under a cooling environment of -5 °C. After the dropwise addition, raise the temperature of the reaction system to 10 °C, slowly dropwise add an aqueous NaOH solution (13 g dissolved in 40 ml of water, completed dropwise addition in 30 min). Continue to stir the reaction for 2 hours. After completion, the reaction system is layered. Separate the aqueous phase. Wash the organic phase three times with water, then add 6 g of anhydrous sodium sulfate for drying and filter to obtain an intermediate solution;

[0143] (2) Add the intermediate solution to a 1 L reactor, add 235.5 g (1.28 mol) of dodecylamine, raise the temperature to 130 - 140 °C and react for 4 h. Take a sample for liquid phase detection. When no intermediate can be detected, lower the temperature; add an NaOH solution (26 g dissolved in 80 g of water), stir until the solid dissolves, let it stand and layer. Separate the aqueous phase. Wash the organic phase three times with water and then distill off the light components under reduced pressure. The residual liquid is cooled and solidified to obtain the target product (Compound I-11).

[0144] 1 H-NMR(300MHz,DMSO-d 6 )δ8.44 - 8.12(m,1H),7.38(d,J=18Hz,2H),6.50(d,J=18Hz,2H),4.86(s,1H),3.38(s,1H),3.19(s,4H),1.75 - 1.72(m,1H),1.49(s,6H),1.25(s,40H),1.05(d,J=6Hz,3H),0.90(d,J=6Hz,3H)0.87 - 0.84(m,10H).

[0145] Example 12: 2-(4-(1,4-dimethyl)pentylamino)aniline-4,6-bis(dodecylamine)-1,3,5-triazine (Compound I-12)

[0146]

[0147] (1) Add 60 g of TCT (0.32 mol) and 400 ml of xylene to a 1 L three-necked flask. Slowly drip a toluene solution of 72.1 g of 4-(1,4-dimethyl)pentylamino-aniline (0.35 mol of 4-(1,4-dimethyl)pentylamino-aniline dissolved in 80 mL of toluene, and the dripping is completed in about 30 min) into the flask under a cooling environment of -5 °C. After the dripping is completed, raise the temperature of the reaction system to 10 °C, and slowly drip an aqueous NaOH solution (13 g dissolved in 40 ml of water, and the dripping is completed in 30 min). Continue to stir the reaction for 2 hours. After the reaction is completed, the reaction system is separated into layers. Separate the aqueous phase, wash the organic phase three times with water, then add 6 g of anhydrous sodium sulfate for drying, and filter to obtain an intermediate solution;

[0148] (2) Add the intermediate solution to a 1 L reaction kettle, add 235.5 g (1.28 mol) of dodecylamine, raise the temperature to 140 - 150 °C and react for 4 h. Take a sample for liquid phase detection. When the intermediate cannot be detected, lower the temperature; add an NaOH solution (26 g dissolved in 80 g of water), stir until the solid dissolves, let it stand for separation into layers, separate the aqueous phase, wash the organic phase three times with water, and then distill off the light components under reduced pressure. The residual liquid is cooled and solidified to obtain the target product (Compound I-12).

[0149] 1 H-NMR (300 MHz, DMSO-d 6 ) δ8.43 - 8.10 (m, 1H), 7.40 (d, J = 18 Hz, 2H), 6.56 (s, 2H), 6.43 (d, J = 18 Hz, 2H), 4.88 (s, 1H), 3.46 (s, 1H), 3.19 (s, 4H), 1.48 (s, 6H), 1.27 - 1.23 (m, 44H), 1.07 (d, J = 6 Hz, 3H), 0.93 (d, J = 6 Hz, 1H), 0.87 - 0.84 (m, 10H).

[0150] Test Example:

[0151] Prepare the mixed rubber compounds of Test Examples 1 - 4 according to the formula shown in Table 1, and conduct application performance tests, which specifically include the following steps:

[0152] 1. Add natural rubber SCR5 and synthetic rubber BR to a mixer. After kneading for a period of time, add carbon black N550, aromatic oil, zinc oxide, stearic acid, and anti-aging agents (6PPD, Compound I-1, Compound I-4, or Compound I-7), and continue to knead until evenly mixed; control the temperature between 150 °C and 160 °C during kneading;

[0153] 2. Cool the entire mixture to below 100 °C, then add a cross-linking system (sulfur S and accelerator NS), and knead the entire mixture; control the temperature not to exceed 110 °C during kneading;

[0154] 3. Calender the obtained rubber composition into a sheet (thickness: 2 - 3 mm), and perform vulcanization at a vulcanization temperature of 145°C for 30 minutes.

[0155] The sources of the components in Table 1 are as follows:

[0156] SCR5: Natural rubber SCR5 from Sinochem Rubber Co., Ltd., Xishuangbanna;

[0157] BR: Synthetic rubber BR9000 from Nanjing Yangzi Petrochemical Rubber Co., Ltd.;

[0158] N550: Carbon black N550 from Cabot Corporation;

[0159] Aromatic oil: General reagent from Shanghai Titan Scientific Co., Ltd.;

[0160] Stearic acid: General reagent stearic acid (AR) from Shanghai Titan Scientific Co., Ltd.;

[0161] Zinc oxide: General reagent zinc oxide (AR) from Shanghai Titan Scientific Co., Ltd.;

[0162] NS: Vulcanization accelerator NS from ShengAo Chemical Technology Co., Ltd.;

[0163] S: Sublimed sulfur (AR) from Sinopharm Chemical Reagent Co., Ltd.;

[0164] 6PPD: Antioxidant SIRANTOX 6PPD from ShengAo Chemical Technology Co., Ltd.;

[0165] Compound I - 1: The compound synthesized in Example 1;

[0166] Compound I - 4: The compound synthesized in Example 4;

[0167] Compound I - 7: The compound synthesized in Example 7.

[0168] Table 1: Formulation of the rubber composition (unit: parts by mass)

[0169]

[0170]

[0171] Evaluate the antioxidant performance and color fastness of the vulcanized rubber sheets in Test Examples 1 - 4 according to the following method.

[0172] (1) Evaluation of antioxidant performance:

[0173] The vulcanized film was aged for 24 h and 48 h in a hot air aging oven at 100 °C. According to GB / T 528-1992 "Rubber, vulcanized or thermoplastic - Determination of tensile stress - strain properties", the tensile strength and elongation at break before and after aging were measured, and the retention rate of the tensile product (the product of the tensile strength and elongation at break) was calculated; according to GB / T 529-1999 "Rubber, vulcanized or thermoplastic - Determination of tear strength", the tear strength before and after aging was measured, and the retention rate of tear strength was calculated. The higher the retention rate, the better the stability and the stronger the antioxidant ability. The test results are as Figure 1 and Figure 2 shown.

[0174] From Figure 1 and Figure 2 the test results, it can be seen that there are slight differences in the retention rate of the tensile product after aging for 24 h. The retention rate of the tensile product of Test Example 2 containing Compound I-1 is the highest, and the other test examples are similar; after aging for 48 h, the retention rate of the tensile product of Test Example 4 containing Compound I-7 is the highest; after aging for 48 h, the retention rate of the tear strength of Test Example 3 containing Compound I-4 is the highest, higher than other test examples. Overall, the antioxidant performance of the anti-aging agent of the present invention is superior to that of the traditional anti-aging agent 6PPD.

[0175] (2) Evaluation of color change performance under weather aging:

[0176] After the vulcanized film was aged in the natural weather environment for three weeks, according to ASTM D1729 (Standard Test Method for Color - Difference Evaluation of Opaque Materials), a color - difference tester CS-10 / 200 / 210 / 220 was used to measure the color difference between the film and the blank sample without anti-aging agent. The evaluation criteria are shown in Table 2 and Figure 3 shown, where L* represents black and white, + represents white - biased, - represents black - biased; a* represents red and green, + represents red - biased, - represents green - biased; b* represents yellow and blue, + represents yellow - biased, - represents blue - biased; ΔE* represents the total color difference. The test results are shown in Table 3.

[0177] According to the measured data and evaluation criteria, it can be seen that the total color difference ΔE* between Test Example 1 containing anti-aging agent 6PPD and the blank sample is the largest, reaching 11.08, the color difference is very large, and the color - resistance ability is poor; while the absolute values of the total color difference ΔE* of the three test examples containing Compound I-1, I-4 and I-7 and the blank sample are all very small, all within the range of 0 - 0.5, belonging to a small and acceptable degree, and the color - resistance ability is strong. The experimental results show that the color - resistance performance of the anti-aging agent of the present invention is superior to that of the traditional anti-aging agent 6PPD.

[0178] Table 2: Color - difference evaluation criteria

[0179] ΔE* range Color difference (tolerance) 0～0.25 Very small or none; ideal match 0.25～0.5 Minute; acceptable match 0.5～1.0 Minute to moderate; acceptable in some applications 1.0～2.0 Moderate; acceptable in specific applications 2.0～4.0 Gap; acceptable in specific applications Above 4.0 Very large; unacceptable in most applications

[0180] Table 3: Color - difference test results

[0181]

Claims

1. Compound of formula I: Wherein, R 1 is a branched alkyl group having 4 to 8 carbon atoms, R 2 is a branched alkyl group having 3 to 7 carbon atoms or a phenyl group.

2. The compound of formula I according to claim 1, characterized in that, In formula I, R 1 is tert-butyl, isohexyl or tert-octyl.

3. The compound of formula I according to claim 1, characterized in that, In formula I, R 2 is isopropyl, 1,3-dimethylbutyl, 1,4-dimethylpentyl or phenyl.

4. The compound of formula I according to claim 1, characterized in that, the compound of formula I is selected from:

5. A method for preparing the compound of formula I according to any one of claims 1-4, characterized in that, the method comprises: (1) In the presence of an alkaline solution, cyanuric chloride is reacted with compound A shown by the following formula to obtain intermediate M shown by the following formula: (2) React intermediate M with R 1 NH 2 to obtain the compound of formula I: wherein, R 1 and R 2 are as defined in any one of claims 1-4.

6. The method according to claim 5, characterized in that, the method has one or more of the following characteristics: In the reaction system of step (1), the amount of substance of compound A is 100% - 120% of the amount of substance of cyanuric chloride; The reaction temperature of step (1) is -5 to 10 °C; In the reaction system of step (2), the amount of substance of R 1 NH 2 is 400% to 480% of the amount of substance of intermediate M; and The reaction temperature of step (2) is 60 to 150 °C.

7. A rubber composition, characterized in that, the rubber composition contains the compound of formula I according to any one of claims 1-4.

8. A rubber product, characterized in that, the rubber product contains the rubber composition according to claim 7.

9. The rubber product according to claim 8, characterized in that, the rubber product is a tire.

10. Use of the compound of formula I according to any one of claims 1-4 in improving the antioxidant performance and / or discoloration resistance performance of rubber or rubber products.

11. The use according to claim 10, characterized in that, the rubber product is a tire.

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