A triazine ring-based hindered phenol antioxidant and a method for preparing the same

Abstract

The present application relates to a kind of triazine ring group hindered phenol antioxidant and its preparation method.The method includes: the system including long-chain fatty amine, cyanuric chloride, potassium carbonate and tetrahydrofuran is reacted at 0~5 ℃ for 6~8 h, to obtain intermediate;The system including intermediate, 2,6-di-tert-butyl-4-hydroxymethyl phenol, potassium carbonate and dimethylbenzene is first reacted at 40~60 ℃ for 2~4 h, then reacted at 80~100 ℃ for 5~8 h, to obtain crude product;Crude product is dissolved with methanol aqueous solution, to obtain crude product dissolution system, then make crude product dissolution system crystallize, again by suction filtration and drying, to obtain triazine ring group hindered phenol antioxidant.The preparation condition of the method of the present application is mild, method is simple and easy to operate, the product structure of the triazine ring group hindered phenol antioxidant prepared is reasonable new type, yield is high, can efficiently eliminate DPPH, and the elimination rate when eliminating DPPH balance is as high as 88% or more.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hindered phenolic antioxidants, and relates to a triazine ring-based hindered phenolic antioxidant and a preparation method thereof. BACKGROUND

[0002] Polymeric materials play an indispensable role in modern industry and daily life. However, during the processing, storage and use of the materials, especially under the influence of light, heat or heavy metal ions, the materials will react with oxygen in the air, accelerate the crosslinking and degradation of the polymer chain, and significantly reduce the performance and service life of the materials. This phenomenon is commonly referred to as aging or degradation of the materials.

[0003] In order to effectively delay the aging of the polymeric materials, the use of antioxidants is particularly crucial. An antioxidant is a chemical additive that can significantly inhibit the oxidation process. It can interrupt the oxidation chain reaction by capturing free radicals or decomposing peroxides, thereby delaying the aging process of the polymeric materials. Antioxidants can be divided into primary antioxidants and secondary antioxidants according to their mechanism of action. Primary antioxidants mainly prevent the occurrence of oxidation reactions by capturing free radicals, such as phenolic and amine antioxidants; and secondary antioxidants play a role by decomposing peroxides, commonly including phosphite and sulfide antioxidants.

[0004] At present, hindered phenolic antioxidants are the most widely used type of antioxidants. In recent years, due to their unique structural characteristics, colorless, non-polluting and other advantages, hindered phenolic antioxidants have been widely used in synthetic rubber, polyolefin plastics and textiles. However, the current hindered phenolic antioxidants still have one or more problems such as unreasonable product structure, low yield, low DPPH free radical scavenging rate, and long scavenging time. However, with the continuous increase in demand for polymeric materials and the rapid development of the industry, the demand for antioxidants in society is also increasing, and the development of new high-efficiency antioxidants has become a top priority.

[0005] In view of the above, it is necessary to provide a triazine ring-based hindered phenolic antioxidant and a preparation method thereof. SUMMARY

[0006] In order to solve one or more technical problems in the prior art, the present application provides a triazine ring-based hindered phenolic antioxidant and a preparation method thereof.

[0007] In a first aspect, the present application provides a triazine ring-based hindered phenolic antioxidant, and the structure of the triazine ring-based hindered phenolic antioxidant is shown in the following formula I:

[0008]

[0009] In formula I, 10≤n≤16, and n is a positive integer.

[0010] The present application provides in a second aspect a method for preparing a triazine ring-based hindered phenolic antioxidant, the method comprising the following steps:

[0011] (1) reacting a system comprising a long-chain fatty amine, cyanuric chloride, potassium carbonate and tetrahydrofuran at 0-5°C for 6-8 hours to obtain an intermediate;

[0012] (2) reacting a system comprising the intermediate, 2,6-di-tert-butyl-4-hydroxymethyl phenol, potassium carbonate and xylene first at 40-60°C for 2-4 hours and then at 80-100°C for 5-8 hours to obtain a crude product;

[0013] (3) dissolving the crude product with an aqueous methanol solution to obtain a crude product dissolving system, then crystallizing the crude product dissolving system, and then filtering and drying to obtain the triazine ring-based hindered phenolic antioxidant.

[0014] Preferably, the long-chain fatty amine is one or more of dodecylamine, tetradecylamine, hexadecylamine and octadecylamine.

[0015] Preferably, in step (1), the molar ratio of the long-chain fatty amine, the cyanuric chloride and the potassium carbonate is (1.8-2.2):(1.8-2.2):1, preferably 2:2:1.

[0016] Preferably, in step (2), the molar ratio of the intermediate, the 2,6-di-tert-butyl-4-hydroxymethyl phenol and the potassium carbonate is 1:(1.8-2.2):1, preferably 1:2:1.

[0017] Preferably, the reaction in step (1) and / or step (2) is carried out under a nitrogen atmosphere.

[0018] Preferably, in step (1), the system comprising the long-chain fatty amine, the cyanuric chloride, the potassium carbonate and the tetrahydrofuran is prepared by mixing the cyanuric chloride and the long-chain fatty amine uniformly with the tetrahydrofuran respectively to obtain a cyanuric chloride solution and a long-chain fatty amine solution respectively, and then adding the long-chain fatty amine and a potassium carbonate solution into the cyanuric chloride solution simultaneously to obtain the system comprising the long-chain fatty amine, the cyanuric chloride, the potassium carbonate and the tetrahydrofuran.

[0019] Preferably, in step (2), the system comprising the intermediate, the 2,6-di-tert-butyl-4-hydroxymethyl phenol, the potassium carbonate and the xylene is prepared by mixing the intermediate and the 2,6-di-tert-butyl-4-hydroxymethyl phenol uniformly with the xylene respectively to obtain an intermediate solution and a 2,6-di-tert-butyl-4-hydroxymethyl phenol solution respectively, and then adding the 2,6-di-tert-butyl-4-hydroxymethyl phenol solution and a potassium carbonate solution into the intermediate solution simultaneously to obtain the system comprising the intermediate, the 2,6-di-tert-butyl-4-hydroxymethyl phenol, the potassium carbonate and the xylene.

[0020] Preferably, the triazine ring group hindered phenolic antioxidant has the following structural formula I:

[0021]

[0022] In formula I, 10≤n≤16, and n is a positive integer.

[0023] The present application provides a triazine ring group hindered phenolic antioxidant prepared by the preparation method described in the second aspect of the present application.

[0024] Compared with the prior art, the present application has at least the following beneficial effects:

[0025] The present application takes cyanuric chloride as the core, first substitutes with long-chain fatty amine to synthesize an intermediate, and then substitutes with 2,6-di-tert-butyl-4-hydroxymethyl phenol to synthesize a novel high-efficiency hindered phenolic antioxidant. The preparation method of the present application has mild preparation conditions and simple operation. The triazine ring group hindered phenolic antioxidant prepared by the present application has a reasonable novel product structure, high yield, can efficiently scavenge DPPH, and the scavenging rate of DPPH at equilibrium is as high as 88% or more, the time to reach the equilibrium scavenging rate is short, and the scavenging efficiency is high. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is an infrared spectrum of the intermediate prepared in examples 1-4 of the present application;

[0027] Figure 2 is an infrared spectrum of the triazine ring group hindered phenolic antioxidant prepared in examples 1-4 of the present application;

[0028] Figure 3 is a relationship curve diagram of the scavenging efficiency and scavenging time of the triazine ring group hindered phenolic antioxidant prepared in examples 1-4 of the present application on DPPH free radicals;

[0029] Figure 4 is a result diagram of the scavenging rate of the triazine ring group hindered phenolic antioxidant prepared in examples 1-4 of the present application at DPPH equilibrium. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] The present application provides a triazine ring hindered phenolic antioxidant in a first aspect, and the structural formula of the triazine ring hindered phenolic antioxidant is shown in the following formula I:

[0032]

[0033] In formula I, 10≤n≤16, and n is a positive integer.

[0034] The triazine ring hindered phenolic antioxidant provided by the present application has reasonable and novel product structure, high yield, can efficiently remove DPPH, and the removal rate of DPPH at the balance is up to 88% or more, the time to reach the balance removal rate is short, and the removal efficiency is high.

[0035] The present application provides a preparation method of a triazine ring hindered phenolic antioxidant in a second aspect, and the method comprises the following steps:

[0036] (1) reacting a system comprising a long-chain fatty amine, cyanuric chloride, potassium carbonate and tetrahydrofuran at 0-5°C (for example 0°C, 1°C, 2°C, 3°C, 4°C or 5°C) for 6-8 hours (for example 6, 7 or 8 hours) to obtain an intermediate; in the present application, for example, dodecylamine, tetradecylamine, hexadecylamine and octadecylamine are respectively substituted with cyanuric chloride to synthesize C12-CNCl, C14-CNCl, C16-CNCl and C18-CNCl, and the reaction principle is shown in the following formula (1):

[0037]

[0038] In formula (1), 10≤n≤16, and n is a positive integer; in the reaction of step (1) of the present application, a low-temperature reaction environment (0-5°C) needs to be controlled, which helps to improve the selectivity of the reaction, can effectively control the specific single substitution reaction of cyanuric chloride with long-chain fatty amine, helps to preferentially generate the target intermediate instead of generating too many by-products, is beneficial to improve the yield and purity of the target intermediate, and the slow reaction at low temperature 0-5°C is beneficial to the sufficient contact and uniform reaction of the reactants in step (1), ensures the uniformity of the reaction and the uniformity of the product, which is very crucial for the smooth progress of the subsequent reaction and the quality control of the synthesis of the triazine ring hindered phenolic antioxidant with a specific structure, and is beneficial to ensure that the triazine ring hindered phenolic antioxidant with high yield and high DPPH free radical removal rate is obtained; it is found in the present application that if the reaction temperature of step (1) is too high, an undesirable intermediate will be generated, which will change the specific molecular structure of the target product triazine ring hindered phenolic antioxidant, and will obviously cause the antioxidant activity to decrease.

[0039] (2) the system comprising the intermediate, 2,6-di-tert-butyl-4-hydroxymethylphenol, potassium carbonate and dimethylbenzene is first reacted at 40-60 DEG C (for example 40 DEG C, 45 DEG C, 50 DEG C, 55 DEG C or 60 DEG C) for 2-4 h (for example 2, 3 or 4 h), and then reacted at 80-100 DEG C (for example 80 DEG C, 85 DEG C, 90 DEG C, 95 DEG C or 100 DEG C) for 5-8 h (for example 5, 6, 7 or 8 h), to obtain a crude product; the substitution of the chlorine atoms in the cyanuric chloride molecule can be achieved by controlling the temperature, and the present application finds that the substitution of the second chlorine atom is preferably carried out at 40-60 DEG C, and the substitution of the third chlorine atom is preferably carried out at 80-100 DEG C; the stepwise temperature rising reaction strategy adopted in step (2) of the present application effectively combines the selectivity and completeness of the reaction, avoids the situation that the reaction is not complete in a single temperature range, makes the reaction process make full use of the reaction characteristics at different temperatures, maximizes the yield and purity of the target product, the triazine ring-based hindered phenolic antioxidant, and at the same time ensures the high antioxidant performance of the final product; the stepwise temperature rising strategy adopted in the present application not only optimizes the reaction conditions and reduces the generation of by-products, but also ensures the high quality and high performance of the final product, and is of great significance for realizing the industrial production of the high-performance triazine ring-based hindered phenolic antioxidant with cyanuric chloride as the core, substituted with long-chain aliphatic amine and 2,6-di-tert-butyl-4-hydroxymethylphenol;

[0040] (3) dissolving the crude product with a methanol aqueous solution to obtain a crude product dissolving system, then crystallizing the crude product dissolving system, and then performing suction filtration and drying, to obtain the triazine ring-based hindered phenolic antioxidant; in the present application, for example, C12-CNCl, C14-CNCl, C16-CNCl and C18-CNCl are used as the bridging groups, and are respectively substituted with 2,6-di-tert-butyl-4-hydroxymethylphenol to synthesize the triazine ring-based hindered phenolic antioxidant series products C12-hindered phenol, C14-hindered phenol, C16-hindered phenol and C18-hindered phenol, and the reaction principle is shown in the following formula (2):

[0041]

[0042] In formula (2), 10≤n≤16, and n is a positive integer.

[0043] The present application takes cyanuric chloride as the core, first synthesizes an intermediate by substituting with long-chain fatty amine, then substitutes with 2,6-di-tert-butyl-4-hydroxymethyl phenol by taking the intermediate as a bridging group, and synthesizes a novel high-efficiency hindered phenolic antioxidant, the method prepared by the present application has mild preparation conditions and simple and easy-to-operate method, the product structure of the triazine ring-based hindered phenolic antioxidant prepared by the present application is reasonable and novel, the yield is high, DPPH can be efficiently removed, the removal rate of DPPH at the balance is as high as 88% or more, the time to reach the balance removal rate is short, and the removal efficiency is high.

[0044] According to some preferred embodiments, the long-chain fatty amine is one or more of dodecylamine, tetradecylamine, hexadecylamine and octadecylamine.

[0045] According to some preferred embodiments, in step (1), the molar ratio of the long-chain fatty amine, the cyanuric chloride and the potassium carbonate (K2CO3) is (1.8-2.2):(1.8-2.2):1, preferably 2:2:1.

[0046] According to some preferred embodiments, in step (2), the molar ratio of the intermediate, the 2,6-di-tert-butyl-4-hydroxymethyl phenol and the potassium carbonate is 1:(1.8-2.2):1, preferably 1:2:1; in the present application, preferably, the molar ratio of the long-chain fatty amine, the cyanuric chloride and the potassium carbonate is (1.8-2.2):(1.8-2.2):1, and the molar ratio of the intermediate, the 2,6-di-tert-butyl-4-hydroxymethyl phenol and the potassium carbonate is 1:(1.8-2.2):1, a suitable molar ratio can ensure that the reaction proceeds sufficiently and the side reaction is minimized, which is the key to obtaining a triazine ring-based hindered phenolic antioxidant with high yield, high purity and high antioxidant performance; such accurate ratio design not only optimizes the reaction conditions, but also ensures the quality and performance stability of the final product.

[0047] According to some preferred embodiments, the reaction in step (1) and / or step (2) is carried out under a nitrogen atmosphere.

[0048] According to some preferred embodiments, in step (1), the system comprising long-chain fatty amine, cyanuric chloride, potassium carbonate and tetrahydrofuran is prepared as follows: cyanuric chloride and long-chain fatty amine are mixed uniformly with tetrahydrofuran respectively to obtain cyanuric chloride solution and long-chain fatty amine solution respectively, then long-chain fatty amine and potassium carbonate solution are added into the cyanuric chloride solution simultaneously to obtain the system comprising long-chain fatty amine, cyanuric chloride, potassium carbonate and tetrahydrofuran; the amount of tetrahydrofuran used in the present application is not specifically limited, and can be routinely selected by those skilled in the art, for example, the mass of tetrahydrofuran used for mixing cyanuric chloride is 5-20 times the mass of cyanuric chloride, and the mass of tetrahydrofuran used for mixing long-chain fatty amine is 5-20 times the mass of long-chain fatty amine; in the present application, the potassium carbonate solution is for example a potassium carbonate aqueous solution (K2CO3 aqueous solution) with a concentration of 3-5 mol / L.

[0049] According to some specific embodiments, step (1) is as follows: the required raw materials are accurately weighed according to the molar ratio n(dodecylamine):n(cyanuric chloride):n(potassium carbonate) = 2:2:1; the weighed cyanuric chloride is dissolved in an appropriate amount of tetrahydrofuran to obtain a cyanuric chloride solution, and the cyanuric chloride solution is transferred to a three-necked flask and stirred at 0-5°C under N2 for 30 min; the weighed dodecylamine is dissolved in an appropriate amount of tetrahydrofuran to obtain a dodecylamine solution (long-chain fatty amine solution), and the dodecylamine solution is slowly added to the cyanuric chloride solution using a constant-pressure dropping funnel, while a K2CO3 aqueous solution with a concentration of 5 mol / L is added in proportion; after all the dodecylamine solution and K2CO3 aqueous solution are added, the temperature is maintained at 0-5°C, and the reaction is continued under nitrogen atmosphere for 7 h; during the reaction, thin layer chromatography is used to track the progress of the reaction and to detect the product; after the reaction is completed, solid inorganic salt KCl is removed by negative pressure filtration; the organic solvent tetrahydrofuran is removed by rotary evaporation, and the obtained substance is vacuum dried in a vacuum drying oven at 45°C for 12 h to obtain a dodecylamine intermediate (denoted as C12-CNCl).

[0050] According to some preferred embodiments, in step (2), the system comprising the intermediate, 2,6-di-tert-butyl-4-hydroxymethylphenol, potassium carbonate and xylene is prepared as follows: the intermediate and 2,6-di-tert-butyl-4-hydroxymethylphenol are mixed uniformly with xylene respectively to obtain an intermediate solution and a 2,6-di-tert-butyl-4-hydroxymethylphenol solution respectively, and then the 2,6-di-tert-butyl-4-hydroxymethylphenol solution and a potassium carbonate solution are added dropwise into the intermediate solution simultaneously to obtain the system comprising the intermediate, 2,6-di-tert-butyl-4-hydroxymethylphenol, potassium carbonate and xylene; the amount of xylene used in the present application is not specifically limited, and can be selected conventionally by those skilled in the art, for example, the mass of xylene used for mixing the intermediate is 40-80 times the mass of the intermediate, and the mass of xylene used for 2,6-di-tert-butyl-4-hydroxymethylphenol is 20-40 times the mass of 2,6-di-tert-butyl-4-hydroxymethylphenol; in the present application, the potassium carbonate solution is for example a potassium carbonate aqueous solution (K2CO3 aqueous solution) with a concentration of 3-5 mol / L.

[0051] According to some specific embodiments, step (2) is as follows: the required raw materials are weighed according to the molar ratio n(C12-CNCl):n(2,6-di-tert-butyl-4-hydroxymethylphenol):n(potassium carbonate) = 1:2:1; the weighed intermediate C12-CNCl is dissolved in an appropriate amount of xylene under ultrasonic conditions to obtain an intermediate solution, and the intermediate solution is transferred to a three-necked flask and stirred at 50°C under N2 for 30 min; the weighed 2,6-di-tert-butyl-4-hydroxymethylphenol is dissolved in an appropriate amount of xylene to obtain a 2,6-di-tert-butyl-4-hydroxymethylphenol solution, and the 2,6-di-tert-butyl-4-hydroxymethylphenol solution is slowly added to the intermediate solution using a constant-pressure dropping funnel, while a K2CO3 aqueous solution with a concentration of 3 mol / L is added dropwise in proportion; after all the 2,6-di-tert-butyl-4-hydroxymethylphenol solution and K2CO3 aqueous solution are added dropwise, the temperature is maintained at 50°C, and the reaction is continued under a nitrogen atmosphere for 3 h, and then the temperature is increased to 90°C, and the reaction is continued under a nitrogen atmosphere for 6 h; after the reaction is completed, solid inorganic salt KCl is removed by negative pressure filtration; the organic solvent xylene is removed by reduced pressure distillation, and the obtained substance is vacuum dried in a vacuum drying box at 65°C for 12 h to obtain the crude product.

[0052] According to some specific embodiments, step (3) is: in order to purify the product, the crude product is added into a three-necked flask, and an aqueous methanol solution (the aqueous methanol solution is composed of methanol and water, the volume ratio of methanol to water is (6-8):(2-4), and the mass of the aqueous methanol solution is 5-10 times the mass of the crude product) is added into the three-necked flask; while slowly stirring, the system is heated to 85°C and condensed to reflux until the final crude product is completely dissolved and the system is clear (condensed to reflux at 85°C for 10-15 min); then, the temperature of the system is lowered, and the system is slowly crystallized (gradually lowered from 85°C to room temperature); the present application does not make a specific limitation on the operation of lowering the temperature of the system, for example, the system can be lowered in temperature by using natural cooling; after the system is cooled to room temperature (or placed in a refrigerator for further crystallization), the final refined product, the triazine ring-based hindered phenolic antioxidant, is obtained by reduced pressure filtration and vacuum drying; in the present application, room temperature refers to room temperature of 20-30°C; the present application does not make a specific limitation on the stirring rate, which can be 200-800 r / min.

[0053] According to some preferred embodiments, the triazine ring-based hindered phenolic antioxidant has the following structural formula I:

[0054]

[0055] In formula I, 10≤n≤16, and n is a positive integer.

[0056] In a third aspect, the present application provides a triazine ring-based hindered phenolic antioxidant prepared by the preparation method described in the second aspect of the present application.

[0057] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application. In the absence of specific description, the reaction raw materials used in the embodiments and comparative examples of the present application can be commercially purchased or synthesized by existing methods.

[0058] Embodiment 1

[0059] The present embodiment provides a preparation method of a triazine ring-based hindered phenolic antioxidant, and the specific steps are as follows:

[0060] ① The required raw materials are accurately weighed according to the molar ratio n (dodecylamine) : n (cyanuric chloride) : n (potassium carbonate) = 2:2:1; the weighed cyanuric chloride is dissolved in an appropriate amount of tetrahydrofuran (the mass of tetrahydrofuran is 5 times the mass of cyanuric chloride) to obtain a cyanuric chloride solution, and the cyanuric chloride solution is transferred to a three-necked flask and stirred at 3°C under N2 for 30 min; the weighed dodecylamine is dissolved in an appropriate amount of tetrahydrofuran (the mass of tetrahydrofuran is 12.5 times the mass of dodecylamine) to obtain a dodecylamine solution (long-chain fatty amine solution), and the dodecylamine solution is slowly added to the cyanuric chloride solution using a constant-pressure dropping funnel, while a K2CO3 aqueous solution with a concentration of 5 mol / L is added in proportion; after the addition of all the dodecylamine solution and K2CO3 aqueous solution is completed, the temperature is maintained at 3°C, and the reaction is continued under a nitrogen atmosphere for 7 h; after the reaction is completed, the solid inorganic salt KCl is removed by negative pressure filtration; the organic solvent tetrahydrofuran is removed by rotary evaporation, and the obtained substance is vacuum dried in a vacuum drying box at 45°C for 12 h to obtain a dodecylamine intermediate (denoted as C12-CNCl).

[0061] ② The required raw materials are accurately weighed according to the molar ratio n (C12-CNCl) : n (2,6-di-tert-butyl-4-hydroxymethylphenol) : n (potassium carbonate) = 1:2:1; the weighed intermediate C12-CNCl is dissolved in an appropriate amount of dimethylbenzene (the mass of dimethylbenzene is 60 times the mass of the intermediate C12-CNCl) to obtain an intermediate solution, and the intermediate solution is transferred to a three-necked flask and stirred at 50°C under N2 for 30 min; the weighed 2,6-di-tert-butyl-4-hydroxymethylphenol is dissolved in an appropriate amount of dimethylbenzene (the mass of dimethylbenzene is 25 times the mass of 2,6-di-tert-butyl-4-hydroxymethylphenol) to obtain a 2,6-di-tert-butyl-4-hydroxymethylphenol solution, and the 2,6-di-tert-butyl-4-hydroxymethylphenol solution is slowly added to the intermediate solution using a constant-pressure dropping funnel, while a K2CO3 aqueous solution with a concentration of 3 mol / L is added in proportion; after the addition of all the 2,6-di-tert-butyl-4-hydroxymethylphenol solution and K2CO3 aqueous solution is completed, the temperature is maintained at 50°C, and the reaction is continued under a nitrogen atmosphere for 3 h, and then the temperature is increased to 90°C, and the reaction is continued under a nitrogen atmosphere for 6 h; after the reaction is completed, the solid inorganic salt KCl is removed by negative pressure filtration; the organic solvent dimethylbenzene is removed by reduced-pressure distillation, and the obtained substance is vacuum dried in a vacuum drying box at 65°C for 12 h to obtain a crude product.

[0062] ③The crude product is added to a three-necked flask, and methanol aqueous solution (consisting of methanol and water, the volume ratio of methanol to water being 8:2) is added thereto, the mass of the methanol aqueous solution being 8 times the mass of the crude product; while stirring slowly, the system is warmed to 85°C and condensed to reflux until the final crude product is completely dissolved and the system is clear, and the condensation to reflux at 85°C is continued for 15 min; then, the temperature of the system is lowered, and the system is slowly crystallized; after the system is cooled to room temperature 25°C, the final refined product, triazine ring-based hindered phenolic antioxidant (denoted as C12-hindered phenol), is obtained by reduced-pressure suction filtration and vacuum drying at 55°C for 12 h.

[0063] Example 2

[0064] The present example provides a preparation method of a triazine ring-based hindered phenolic antioxidant, and the specific steps are as follows:

[0065] ①The required raw materials are accurately weighed according to the molar ratio n(tetradecylamine):n(tricyanochloride):n(potassium carbonate) = 2:2:1; the weighed tricyanochloride is dissolved in an appropriate amount of tetrahydrofuran (the mass of the tetrahydrofuran being 5 times the mass of the tricyanochloride) to obtain a tricyanochloride solution, and the tricyanochloride solution is transferred to a three-necked flask and stirred at 3°C under N2for 30 min; the weighed tetradecylamine is dissolved in an appropriate amount of tetrahydrofuran (the mass of the tetrahydrofuran being 12 times the mass of the tetradecylamine) to obtain a tetradecylamine solution (long-chain aliphatic amine solution), and the tetradecylamine solution is slowly added to the tricyanochloride solution using a constant-pressure dropping funnel, and a K2CO3aqueous solution with a concentration of 5 mol / L is added in proportion; after the addition of all the tetradecylamine solution and the K2CO3aqueous solution is completed, the temperature is maintained at 3°C, and the reaction is continued under a nitrogen atmosphere for 7 h; after the reaction is completed, the solid inorganic salt KCl is removed by negative pressure filtration; the organic solvent tetrahydrofuran is removed by rotary evaporation, and the obtained substance is vacuum dried in a vacuum drying oven at 45°C for 12 h to obtain a tetradecylamine intermediate (denoted as C14-CNCl).

[0066] (2) The intermediate C14-CNCl was dissolved in a certain amount of xylene (the mass of xylene was 65 times the mass of the intermediate C14-CNCl), and the intermediate solution was obtained and transferred to a three-necked flask, and stirred at 50°C under N2for 30 min. The 2,6-di-tert-butyl-4-hydroxymethylphenol was dissolved in a certain amount of xylene (the mass of xylene was 25 times the mass of the 2,6-di-tert-butyl-4-hydroxymethylphenol), and the 2,6-di-tert-butyl-4-hydroxymethylphenol solution was obtained. The 2,6-di-tert-butyl-4-hydroxymethylphenol solution was slowly added to the intermediate solution by using a constant pressure dropping funnel, and a K2CO3aqueous solution with a concentration of 3 mol / L was added at the same time. After the addition of all the 2,6-di-tert-butyl-4-hydroxymethylphenol solution and the K2CO3aqueous solution was completed, the temperature was maintained at 50°C, and the reaction was continued under a nitrogen atmosphere for 3 h, and then the temperature was increased to 90°C, and the reaction was continued under a nitrogen atmosphere for 6 h. After the reaction was completed, the solid inorganic salt KCl was removed by negative pressure filtration. The organic solvent xylene was removed by vacuum distillation, and the obtained substance was vacuum dried at 65°C in a vacuum drying box for 12 h, to obtain the crude product.

[0067] (3) The crude product was added to a three-necked flask, and methanol aqueous solution (the methanol aqueous solution was composed of methanol and water, and the volume ratio of methanol to water was 8:2) was added to the three-necked flask, and the mass of the methanol aqueous solution was 8 times the mass of the crude product. While slowly stirring, the system was heated to 85°C and condensed to reflux, until the final crude product was completely dissolved and the system was clear, and the system was continuously condensed to reflux at 85°C for 15 min. Then, the temperature of the system was decreased, and the system was slowly crystallized. After the system was cooled to room temperature 25°C, the final refined product triazine ring-based hindered phenolic antioxidant (denoted as C14-hindered phenol) was obtained by vacuum filtration under reduced pressure and vacuum drying at 55°C for 12 h.

[0068] Example 3

[0069] The present embodiment provides a preparation method of a triazine ring-based hindered phenolic antioxidant, and the specific steps are as follows:

[0070] ① The required raw materials are accurately weighed according to the molar ratio n (hexadecylamine) : n (cyanuric chloride) : n (potassium carbonate) = 2:2:1; the weighed cyanuric chloride is dissolved in an appropriate amount of tetrahydrofuran (the mass of tetrahydrofuran is 5 times the mass of cyanuric chloride) to obtain a cyanuric chloride solution, and the cyanuric chloride solution is transferred to a three-necked flask and stirred at 3°C under N2 for 30 min; the weighed hexadecylamine is dissolved in an appropriate amount of tetrahydrofuran (the mass of tetrahydrofuran is 9.2 times the mass of hexadecylamine) to obtain a hexadecylamine solution (long-chain aliphatic amine solution), and the hexadecylamine solution is slowly added to the cyanuric chloride solution using a constant-pressure dropping funnel, while a K2CO3 aqueous solution with a concentration of 5 mol / L is added in proportion; after the addition of all the hexadecylamine solution and K2CO3 aqueous solution is completed, the temperature is maintained at 3°C, and the reaction is continued under a nitrogen atmosphere for 7 h; after the reaction is completed, the solid inorganic salt KCl is removed by negative pressure filtration; the organic solvent tetrahydrofuran is removed by rotary evaporation, and the obtained substance is vacuum dried in a vacuum drying box at 45°C for 12 h to obtain a hexadecylamine intermediate (denoted as C16-CNCl).

[0071] ② The required raw materials are accurately weighed according to the molar ratio n (C16-CNCl) : n (2,6-di-tert-butyl-4-hydroxymethylphenol) : n (potassium carbonate) = 1:2:1; the weighed intermediate C16-CNCl is dissolved in an appropriate amount of dimethylbenzene (the mass of dimethylbenzene is 45 times the mass of the intermediate C16-CNCl) to obtain an intermediate solution, and the intermediate solution is transferred to a three-necked flask and stirred at 50°C under N2 for 30 min; the weighed 2,6-di-tert-butyl-4-hydroxymethylphenol is dissolved in an appropriate amount of dimethylbenzene (the mass of dimethylbenzene is 25 times the mass of 2,6-di-tert-butyl-4-hydroxymethylphenol) to obtain a 2,6-di-tert-butyl-4-hydroxymethylphenol solution, and the 2,6-di-tert-butyl-4-hydroxymethylphenol solution is slowly added to the intermediate solution using a constant-pressure dropping funnel, while a K2CO3 aqueous solution with a concentration of 3 mol / L is added in proportion; after the addition of all the 2,6-di-tert-butyl-4-hydroxymethylphenol solution and K2CO3 aqueous solution is completed, the temperature is maintained at 50°C, and the reaction is continued under a nitrogen atmosphere for 3 h, and then the temperature is increased to 90°C, and the reaction is continued under a nitrogen atmosphere for 6 h; after the reaction is completed, the solid inorganic salt KCl is removed by negative pressure filtration; the organic solvent dimethylbenzene is removed by reduced-pressure distillation, and the obtained substance is vacuum dried in a vacuum drying box at 65°C for 12 h to obtain a crude product.

[0072] ③The crude product is added to a three-necked flask, and methanol aqueous solution (consisting of methanol and water, the volume ratio of methanol to water being 8:2) is added thereto, the mass of the methanol aqueous solution being 8 times the mass of the crude product; while stirring slowly, the system is warmed to 85°C and condensed to reflux until the final crude product is completely dissolved and the system is clear, and the condensation to reflux at 85°C is continued for 15 min; then, the temperature of the system is lowered, and the system is slowly crystallized; after the system is cooled to room temperature 25°C, the final refined product, triazine ring-based hindered phenol antioxidant (denoted as C16-hindered phenol), is obtained by reduced-pressure suction filtration and vacuum drying at 55°C for 12 h.

[0073] Example 4

[0074] The present example provides a preparation method of a triazine ring-based hindered phenol antioxidant, and the specific steps are as follows:

[0075] ①The required raw materials are accurately weighed according to the molar ratio n(octadecylamine):n(tricyanochloride):n(potassium carbonate) = 2:2:1; the weighed tricyanochloride is dissolved in an appropriate amount of tetrahydrofuran (the mass of the tetrahydrofuran being 5 times the mass of the tricyanochloride) to obtain a tricyanochloride solution, and the tricyanochloride solution is transferred to a three-necked flask and stirred at 3°C under N2for 30 min; the weighed octadecylamine is dissolved in an appropriate amount of tetrahydrofuran (the mass of the tetrahydrofuran being 12 times the mass of the octadecylamine) to obtain an octadecylamine solution (long-chain aliphatic amine solution), and the octadecylamine solution is slowly added to the tricyanochloride solution through a constant-pressure dropping funnel, and a K2CO3aqueous solution with a concentration of 5 mol / L is added in proportion; after the addition of all the octadecylamine solution and the K2CO3aqueous solution is completed, the temperature is maintained at 3°C, and the reaction is continued under a nitrogen atmosphere for 7 h; after the reaction is completed, the solid inorganic salt KCl is removed by negative pressure filtration; the organic solvent tetrahydrofuran is removed by rotary evaporation, and the obtained substance is vacuum dried in a vacuum drying box at 45°C for 12 h to obtain an octadecylamine intermediate (denoted as C18-CNCl).

[0076] ②Accurately weigh the required raw materials according to the molar ratio n(C18-CNCl):n(2,6-di-tert-butyl-4-hydroxymethylphenol):n(potassium carbonate) = 1:2:1; dissolve the weighed intermediate C18-CNCl in an appropriate amount of xylene (the mass of xylene is 56.5 times the mass of intermediate C18-CNCl) to obtain an intermediate solution, and transfer the intermediate solution to a three-necked flask, stirring for 30 min at 50℃ and N2; dissolve the weighed 2,6-di-tert-butyl-4-hydroxymethylphenol in an appropriate amount of xylene (the mass of xylene is 25 times the mass of 2,6-di-tert-butyl-4-hydroxymethylphenol) to obtain 2,6-di-tert-butyl- A 4-hydroxymethylphenol solution was slowly added dropwise to the intermediate solution using a constant-pressure dropping funnel, along with a 3 mol / L K₂CO₃ aqueous solution. After all the 2,6-di-tert-butyl-4-hydroxymethylphenol and K₂CO₃ aqueous solutions had been added, the reaction was continued at 50°C under a nitrogen atmosphere for 3 hours. Then, the temperature was increased to 90°C, and the reaction was continued under a nitrogen atmosphere for 6 hours. After the reaction was completed, the solid inorganic salt KCl was removed by negative pressure filtration. The organic solvent xylene was removed by vacuum distillation. The resulting substance was then vacuum dried at 65°C for 12 hours in a vacuum drying oven to obtain the crude product.

[0077] ③ Add the crude product to a three-necked flask and add a methanol-water solution (composed of methanol and water in a volume ratio of 8:2). The mass of the methanol-water solution is 8 times the mass of the crude product. While stirring slowly, heat the system to 85°C and reflux until the crude product is completely dissolved and the system is clear. Continue to reflux at 85°C for 15 minutes. Then, lower the system temperature to allow the system to crystallize slowly. After the system cools to room temperature (25°C), filter under reduced pressure and dry under vacuum at 55°C for 12 hours to obtain the final purified product, triazine cyclic hindered phenolic antioxidant (denoted as C18-hinderedphenol).

[0078] The infrared spectra of the intermediates obtained in Examples 1-4 of this invention are as follows: Figure 1 As shown; from Figure 1 It can be seen that the infrared spectra of these four long-chain aliphatic amine intermediates show a high degree of consistency, with the absorption peak positions of the characteristic functional groups being roughly the same, while the peak intensities show slight differences; taking the intermediate C18-CNCl as an example, at 796 cm⁻¹... -1 The peak corresponds to the stretching vibration of the C-Cl bond, and is 1559 cm⁻¹. -1 and 1438cm -1 The absorption peak at 2924 cm⁻¹ confirms the presence of the triazine ring; -1 and 2848cm -1The absorption peaks at 725 cm⁻¹ correspond to the stretching vibrations of -CH₃ and -CH₂, respectively, while those at 725 cm⁻¹... -1 The peak at 3324 cm⁻¹ is related to the in-plane rocking motion of the CH₂ group; -1 The presence of a -NH- stretching vibration absorption peak at the left and right positions, and the fact that this peak is singular, proves that cyanuric chloride and octadecylamine have reacted. The infrared spectra of the triazine cyclohexane hindered phenolic antioxidants prepared in Examples 1-4 of this invention are shown below. Figure 2 As shown; from Figure 2 It can be seen that the infrared spectra of these triazine-cyclic hindered phenolic antioxidants show high consistency, with the absorption peak positions of each characteristic functional group being roughly the same, but with slight differences in peak intensity; taking C18-hindered phenol as an example, at 1155 cm⁻¹... -1 A -COC- stretching vibration peak appeared at 796 cm⁻¹, while at 796 cm⁻¹... -1 The C-Cl bond stretching vibration peak in the octadecylamine intermediate disappears, and the peak at 3600 cm⁻¹ disappears. -1 The presence of a stretching vibration peak of -OH indicates that the octadecylamine intermediate reacted with 2,6-di-tert-butyl-4-hydroxymethylphenol.

[0079] The relationship between the scavenging efficiency and scavenging time of the triazine cyclohexyl hindered phenolic antioxidants prepared in Examples 1-4 of this invention on DPPH free radicals is shown in the graphs. Figure 3 As shown in the figure; the scavenging rate of the triazine cyclo-hindered phenolic antioxidants prepared in Examples 1-4 of this invention at DPPH equilibrium is shown in the figure. Figure 4 As shown; according to Figure 3 and Figure 4 The results, including the DPPH scavenging efficiency and the time to reach scavenging equilibrium of the triazine cyclohedral hindered phenolic antioxidants, are shown in Table 1. The results indicate that the DPPH scavenging efficiency of the triazine cyclohedral hindered phenolic antioxidants in Examples 1-4 decreased with increasing bridging group carbon chain length. This may be because these four hindered phenolic antioxidants terminate free radicals not only by providing hydrogen protons but also by generating phenoxy radicals. However, with increasing bridging group carbon chain length, steric hindrance also increases, reducing the probability of phenoxy radical reactions and leading to a decrease in the overall scavenging efficiency.

[0080] Comparative Example 1

[0081] Comparative Example 1 is basically the same as Example 1, except that:

[0082]

[0083] Comparative Example 2

[0084] Comparative Example 2 is basically the same as Example 1, except that:

[0085] 2. According to the molar ratio n(C12-CNCl):n(2,6-di-tert-butyl-4-hydroxymethylphenol):n(potassium carbonate) = 1:2:1, the required raw materials were accurately weighed; the weighed intermediate C12-CNCl was dissolved in an appropriate amount of xylene (the mass of xylene was 60 times the mass of the intermediate C12-CNCl), to obtain an intermediate solution, and the intermediate solution was transferred to a three-necked flask and stirred at 50°C under N2for 30 min; the weighed 2,6-di-tert-butyl-4-hydroxymethylphenol was dissolved in an appropriate amount of xylene (the mass of xylene was 25 times the mass of 2,6-di-tert-butyl-4-hydroxymethylphenol), to obtain a 2,6-di-tert-butyl-4-hydroxymethylphenol solution, and the 2,6-di-tert-butyl-4-hydroxymethylphenol solution was slowly added to the intermediate solution using a constant-pressure dropping funnel, while a 3 mol / L K2CO3aqueous solution was added in proportion; after all the 2,6-di-tert-butyl-4-hydroxymethylphenol solution and the K2CO3aqueous solution were added, the temperature was maintained at 50°C, and the reaction was continued under a nitrogen atmosphere for 9 h; after the reaction was completed, the solid inorganic salt KCl was removed by negative pressure filtration; the organic solvent xylene was removed by vacuum distillation, and the obtained substance was vacuum dried at 65°C in a vacuum drying box for 12 h, to obtain a crude product; the crude product obtained in this step 2 was used to replace the crude product obtained in step 2 of Example 1 to perform the subsequent step 3. ​

[0086] Comparative Example 3

[0087] Comparative Example 3 is substantially identical to Example 1, except that:

[0088] 2. The required raw materials were accurately weighed according to the mass ratio n(C12-CNCl):n(2,6-di-tert-butyl-4-hydroxymethylphenol):n(potassium carbonate) = 1:2:1; the weighed intermediate C12-CNCl was dissolved in an appropriate amount of xylene (the mass of xylene was 60 times the mass of intermediate C12-CNCl) to obtain an intermediate solution, and the intermediate solution was transferred to a three-necked flask and stirred at 50°C under N2for 30 min; the weighed 2,6-di-tert-butyl-4-hydroxymethylphenol was dissolved in an appropriate amount of xylene (the mass of xylene was 25 times the mass of 2,6-di-tert-butyl-4-hydroxymethylphenol) to obtain a 2,6-di-tert-butyl-4-hydroxymethylphenol solution, and the 2,6-di-tert-butyl-4-hydroxymethylphenol solution was slowly added to the intermediate solution using a constant-pressure dropping funnel, while a K2CO3aqueous solution with a concentration of 3 mol / L was added in proportion; after all the 2,6-di-tert-butyl-4-hydroxymethylphenol solution and the K2CO3aqueous solution were added, the temperature was increased to 90°C, and the reaction was continued under a nitrogen atmosphere for 9 h; after the reaction was completed, solid inorganic salt KCl was removed by negative pressure filtration; the organic solvent xylene was removed by reduced-pressure distillation, and the obtained substance was vacuum dried at 65°C in a vacuum drying box for 12 h to obtain the crude product; the crude product obtained in this step 2 was used to replace the crude product obtained in step 2 of Example 1 to perform the subsequent step 3.

[0089] Comparative Example 4

[0090] Comparative Example 4 is substantially identical to Example 1, except that:

[0091] ① The required raw materials were accurately weighed according to the molar ratio n (dodecylamine) :n (cyanuric chloride) :n (potassium carbonate) = 2:1.5:1; the weighed cyanuric chloride was dissolved in an appropriate amount of tetrahydrofuran (the mass of tetrahydrofuran was 5 times the mass of cyanuric chloride) to obtain a cyanuric chloride solution, and the cyanuric chloride solution was transferred to a three-necked flask and stirred at 3°C under N2for 30 min; the weighed dodecylamine was dissolved in an appropriate amount of tetrahydrofuran (the mass of tetrahydrofuran was 12.5 times the mass of dodecylamine) to obtain a dodecylamine solution (long-chain aliphatic amine solution), and the dodecylamine solution was slowly added to the cyanuric chloride solution using a constant-pressure dropping funnel, while a K2CO3aqueous solution with a concentration of 5 mol / L was added in proportion; after the addition of all the dodecylamine solution and K2CO3aqueous solution was completed, the temperature was maintained at 3°C, and the reaction was continued under a nitrogen atmosphere for 7 h; after the reaction was completed, the solid inorganic salt KCl was removed by negative pressure filtration; the organic solvent tetrahydrofuran was removed by rotary evaporation, and the obtained substance was vacuum dried at 45°C in a vacuum drying box for 12 h to obtain the intermediate.

[0092] ② The required raw materials were accurately weighed according to the molar ratio n (intermediate) :n (2,6-di-tert-butyl-4-hydroxymethylphenol) :n (potassium carbonate) = 1:3:1; the weighed intermediate was dissolved in an appropriate amount of xylene (the mass of xylene was 60 times the mass of the intermediate) to obtain an intermediate solution, and the intermediate solution was transferred to a three-necked flask and stirred at 50°C under N2for 30 min; the weighed 2,6-di-tert-butyl-4-hydroxymethylphenol was dissolved in an appropriate amount of xylene (the mass of xylene was 25 times the mass of 2,6-di-tert-butyl-4-hydroxymethylphenol) to obtain a 2,6-di-tert-butyl-4-hydroxymethylphenol solution, and the 2,6-di-tert-butyl-4-hydroxymethylphenol solution was slowly added to the intermediate solution using a constant-pressure dropping funnel, while a K2CO3aqueous solution with a concentration of 3 mol / L was added in proportion; after the addition of all the 2,6-di-tert-butyl-4-hydroxymethylphenol solution and K2CO3aqueous solution was completed, the temperature was maintained at 50°C, and the reaction was continued under a nitrogen atmosphere for 3 h, and then the temperature was increased to 90°C, and the reaction was continued under a nitrogen atmosphere for 6 h; after the reaction was completed, the solid inorganic salt KCl was removed by negative pressure filtration; the organic solvent xylene was removed by reduced-pressure distillation, and the obtained substance was vacuum dried at 65°C in a vacuum drying box for 12 h to obtain a crude product; the crude product obtained in step ② was used in the subsequent step ③ instead of the crude product obtained in step ② of Example 1.

[0093] Comparative Example 5

[0094] Comparative Example 5 is basically the same as Example 1, except that:

[0095] ① The required raw materials were accurately weighed according to the molar ratio n (dodecylamine) :n (tricyanochloroethylene) :n (potassium carbonate) =2:2.5:1; the weighed tricyanochloroethylene was dissolved in an appropriate amount of tetrahydrofuran (the mass of tetrahydrofuran was 5 times the mass of tricyanochloroethylene) to obtain a tricyanochloroethylene solution, and the tricyanochloroethylene solution was transferred to a three-necked flask and stirred at 3°C under N2for 30 min; the weighed dodecylamine was dissolved in an appropriate amount of tetrahydrofuran (the mass of tetrahydrofuran was 12.5 times the mass of dodecylamine) to obtain a dodecylamine solution (long-chain aliphatic amine solution), and the dodecylamine solution was slowly added to the tricyanochloroethylene solution using a constant-pressure dropping funnel, while a K2CO3aqueous solution with a concentration of 5 mol / L was added in proportion; after the addition of all the dodecylamine solution and K2CO3aqueous solution was completed, the temperature was maintained at 3°C, and the reaction was continued under a nitrogen atmosphere for 7 h; after the reaction was completed, the solid inorganic salt KCl was removed by negative pressure filtration; the organic solvent tetrahydrofuran was removed by rotary evaporation, and the obtained substance was vacuum dried at 45°C in a vacuum drying box for 12 h to obtain the intermediate.

[0096] ② The required raw materials were accurately weighed according to the molar ratio n (intermediate) :n (2,6-di-tert-butyl-4-hydroxymethylphenol) :n (potassium carbonate) =1:1.5:1; the weighed intermediate was dissolved in an appropriate amount of dimethylbenzene (the mass of dimethylbenzene was 60 times the mass of the intermediate) to obtain an intermediate solution, and the intermediate solution was transferred to a three-necked flask and stirred at 50°C under N2for 30 min; the weighed 2,6-di-tert-butyl-4-hydroxymethylphenol was dissolved in an appropriate amount of dimethylbenzene (the mass of dimethylbenzene was 25 times the mass of 2,6-di-tert-butyl-4-hydroxymethylphenol) to obtain a 2,6-di-tert-butyl-4-hydroxymethylphenol solution, and the 2,6-di-tert-butyl-4-hydroxymethylphenol solution was slowly added to the intermediate solution using a constant-pressure dropping funnel, while a K2CO3aqueous solution with a concentration of 3 mol / L was added in proportion; after the addition of all the 2,6-di-tert-butyl-4-hydroxymethylphenol solution and K2CO3aqueous solution was completed, the temperature was maintained at 50°C, and the reaction was continued under a nitrogen atmosphere for 3 h, and then the temperature was increased to 90°C, and the reaction was continued under a nitrogen atmosphere for 6 h; after the reaction was completed, the solid inorganic salt KCl was removed by negative pressure filtration; the organic solvent dimethylbenzene was removed by reduced-pressure distillation, and the obtained substance was vacuum dried at 65°C in a vacuum drying box for 12 h to obtain a crude product; the crude product obtained in step ② was used in the subsequent step ③ to replace the crude product obtained in step ② of Example 1.

[0097] Comparative Example 6

[0098] ① The required raw materials were accurately weighed according to the mass ratio n (cyanuric chloride) : n (2, 6-di-tert-butyl-4-hydroxymethyl phenol) : n (potassium carbonate) = 1:3:1; cyanuric chloride was dissolved in a proper amount of dimethylbenzene (the mass of dimethylbenzene was 5 times the mass of cyanuric chloride) to obtain a cyanuric chloride solution, and the cyanuric chloride solution was transferred to a three-necked flask and stirred at 50°C under N2for 30 min; 2, 6-di-tert-butyl-4-hydroxymethyl phenol was dissolved in a proper amount of dimethylbenzene (the mass of dimethylbenzene was 25 times the mass of 2, 6-di-tert-butyl-4-hydroxymethyl phenol) to obtain a 2, 6-di-tert-butyl-4-hydroxymethyl phenol solution, and the 2, 6-di-tert-butyl-4-hydroxymethyl phenol solution was slowly added to the cyanuric chloride solution by using a constant-pressure dropping funnel, while a K2CO3aqueous solution with a concentration of 3 mol / L was added in proportion; after the addition of all the 2, 6-di-tert-butyl-4-hydroxymethyl phenol solution and the K2CO3aqueous solution was completed, the temperature was maintained at 50°C, and the reaction was continued under a nitrogen atmosphere for 3 h, and then the temperature was increased to 90°C, and the reaction was continued under a nitrogen atmosphere for 6 h; after the reaction was completed, KCl was removed by negative pressure filtration; the organic solvent dimethylbenzene was removed by reduced pressure distillation, and the obtained substance was vacuum dried in a vacuum drying oven at 65°C for 12 h to obtain a crude product.

[0099] ② The crude product was added to a three-necked flask, and methanol aqueous solution (the methanol aqueous solution was composed of methanol and water, and the volume ratio of methanol to water was 8:2) was added to the flask, and the mass of the methanol aqueous solution was 8 times the mass of the crude product; while slowly stirring, the system was heated to 85°C and condensed to reflux until the final crude product was completely dissolved and the system was clear, and the system was continuously condensed to reflux at 85°C for 15 min; then, the temperature of the system was decreased, and the system was slowly crystallized; after the system was cooled to room temperature 25°C, a triazine ring-based hindered phenolic antioxidant was obtained by reduced pressure suction filtration and vacuum drying at 55°C for 12 h.

[0100] Comparative Example 7

[0101] Comparative Example 7 is basically the same as Example 1, except that:

[0102]

[0103] Comparative Example 8

[0104] Comparative Example 8 is basically the same as Example 1, except that:

[0105] 2. The intermediate C14-CNCl was dissolved in a suitable amount of xylene (the mass of xylene was 65 times the mass of the intermediate C14-CNCl), to obtain an intermediate solution, and the intermediate solution was transferred to a three-necked flask, which was stirred at 50°C under N2for 30 min. The 2,6-di-tert-butyl-4-aminophenol was dissolved in a suitable amount of xylene (the mass of xylene was 25 times the mass of the 2,6-di-tert-butyl-4-aminophenol), to obtain a 2,6-di-tert-butyl-4-aminophenol solution, which was slowly added to the intermediate solution by using a constant pressure dropping funnel, and a K2CO3aqueous solution with a concentration of 3 mol / L was added at the same time. After all the 2,6-di-tert-butyl-4-aminophenol solution and the K2CO3aqueous solution were added, the temperature was maintained at 50°C, and the reaction was continued under a nitrogen atmosphere for 3 h, and then the temperature was increased to 90°C, and the reaction was continued under a nitrogen atmosphere for 6 h. After the reaction was completed, the solid inorganic salt KCl was removed by negative pressure filtration. The organic solvent xylene was removed by vacuum distillation, and the obtained substance was vacuum dried at 65°C in a vacuum drying box for 12 h, to obtain a crude product. The crude product obtained by this step 2 was used to replace the crude product obtained by step 2 in Example 1 to perform the subsequent step 3.​

[0106] Comparative Example 9

[0107] Comparative Example 9 synthesized an antioxidant 565, i.e. 4-[(4,6-dioctylthio-1,3,5-triazin-2-yl)amino]-2,6-di-tert-butylphenol, according to the synthesis of Example 2 in CN109651280A.

[0108] Comparative Example 10

[0109] Comparative Example 10 synthesized a hindered phenolic antioxidant according to the synthesis of Example 1 in CN115894391A.

[0110] Comparative Example 11

[0111] Comparative Example 11 synthesized a polysubstituted hindered phenolic antioxidant according to the synthesis of Example 1 in CN101805245A.

[0112] Comparative Example 12

[0113] Comparative Example 12 provided a commercially available antioxidant 3114.

[0114] The yield of the hindered phenolic antioxidant finally prepared in Examples 1-4 and Comparative Examples 1-8 of the present application was tested, and the results are shown in Table 1; the clearance rate of the hindered phenolic antioxidant finally prepared in each example and each comparative example when DPPH was cleared and the time when the clearance reached equilibrium were also tested, and the results are shown in Table 1. In the present application, the experiment of clearing DPPH (clearing DPPH free radicals) was carried out as follows: anhydrous ethanol was used as a solvent to prepare a DPPH solution and a hindered phenolic antioxidant solution to be determined, both with a concentration of 1.0 mmol / L; 2 mL of the DPPH solution was taken, and the absorbance thereof at a wavelength of 517 nm was determined using an ultraviolet-visible spectrophotometer, and was recorded as A0; next, 2 mL of the DPPH solution was mixed with 2 mL of the hindered phenolic antioxidant solution to be determined to avoid errors, so that the mixed solution was allowed to react under light shielding conditions for a period of time t, and then the absorbance of the mixed solution at 517 nm was determined again using the ultraviolet-visible spectrophotometer, and was recorded as A t ; finally, the clearance rate E% of the hindered phenolic antioxidant to be determined on DPPH was calculated according to Formula 1-1 below.

[0115]

[0116] Table 1

[0117]

[0118]

[0119] In Table 1, the symbol " / " means that the performance index is not determined or not given.

[0120] The part of the present application not described in detail is the technology known to the person skilled in the art.

[0121] Finally, it should be noted that the above detailed description of the high-efficiency triazine ring-based hindered phenolic antioxidant and the preparation method thereof according to the embodiments of the present application is provided, and specific examples are used in the present text to describe the implementation manner of the present application, and the above description of the embodiments is only used to help understand the method of the present application and its core idea; meanwhile, for the person skilled in the art, the specific implementation manner and application range can be changed according to the idea of the present application, and the above description of the present application should not be understood as a limitation of the present application; although the present application is described in detail with reference to the foregoing embodiments, the person skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A process for the preparation of a triazine ring-based hindered phenolic antioxidant, characterized in that, The method comprises the following steps: (1) reacting a system comprising long-chain fatty amine, cyanuric chloride, potassium carbonate and tetrahydrofuran at 0-5℃ for 6-8h to obtain an intermediate; the molar ratio of the long-chain fatty amine, the cyanuric chloride and the potassium carbonate is (1.8-2.2):(1.8-2.2):1; (2) reacting a system comprising the intermediate, 2,6-di-tert-butyl-4-hydroxymethyl phenol, potassium carbonate and dimethylbenzene at 40-60℃ for 2-4h and then at 80-100℃ for 5-8h to obtain a crude product; the molar ratio of the intermediate, the 2,6-di-tert-butyl-4-hydroxymethyl phenol and the potassium carbonate is 1:(1.8-2.2):1; (3) dissolving the crude product with a methanol aqueous solution to obtain a crude product dissolving system, then crystallizing the crude product dissolving system, and then filtering and drying to obtain a triazine ring-based hindered phenolic antioxidant; the clearance rate of the triazine ring-based hindered phenolic antioxidant when clearing DPPH is as high as 88% or more, and the structural formula of the triazine ring-based hindered phenolic antioxidant is shown in the following formula I: In formula I, 10≤n≤16, and n is a positive integer.

2. The preparation method according to claim 1, characterized in that: The long-chain fatty amine is one or more of dodecylamine, tetradecylamine, hexadecylamine and octadecylamine.

3. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of the long-chain fatty amine, the cyanuric chloride and the potassium carbonate is 2:2:

1.

4. The preparation method according to claim 1, characterized in that: In step (2), the molar ratio of the intermediate, the 2,6-di-tert-butyl-4-hydroxymethyl phenol and the potassium carbonate is 1:2:

1.

5. The preparation method according to claim 1, characterized in that: The reaction in step (1) and / or step (2) is carried out under a nitrogen atmosphere.

6. The preparation method according to claim 1, characterized in that: In step (1), the system comprising long-chain fatty amine, cyanuric chloride, potassium carbonate and tetrahydrofuran is prepared as follows: tetrahydrofuran is used to uniformly mix cyanuric chloride and long-chain fatty amine respectively to obtain cyanuric chloride solution and long-chain fatty amine solution respectively, then long-chain fatty amine and potassium carbonate solution are simultaneously added into the cyanuric chloride solution to obtain the system comprising long-chain fatty amine, cyanuric chloride, potassium carbonate and tetrahydrofuran.

7. The preparation method according to claim 1, characterized in that: In step (2), the system comprising the intermediate, 2,6-di-tert-butyl-4-hydroxymethyl phenol, potassium carbonate and dimethylbenzene is prepared as follows: dimethylbenzene is used to uniformly mix the intermediate and 2,6-di-tert-butyl-4-hydroxymethyl phenol respectively to obtain intermediate solution and 2,6-di-tert-butyl-4-hydroxymethyl phenol solution respectively, then 2,6-di-tert-butyl-4-hydroxymethyl phenol solution and potassium carbonate solution are simultaneously added into the intermediate solution to obtain the system comprising the intermediate, 2,6-di-tert-butyl-4-hydroxymethyl phenol, potassium carbonate and dimethylbenzene. ​

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