阅读说明：本技术 大分子受阻酚类抗氧剂及其制备方法与应用 (Macromolecular hindered phenol antioxidant and preparation method and application thereof ) 是由 王玉如 任鹤 何书艳 闫义彬 王登飞 赵增辉 吴双 牛娜 张明强 张瑞 王斯晗 于 2020-04-10 设计创作，主要内容包括：本发明公开一种大分子受阻酚类抗氧剂及其制备方法与应用,该大分子受阻酚类抗氧剂具有如下结构：其中,R-(1)、R-(2)、R-(3)、R-(4)和R-(5)独立为具有1-20个碳的烃基。制备方法包括如下步骤：步骤1,2,6-二烷基苯酚和多聚甲醛在催化剂和醇的存在下进行反应,生成3,5-二烷基-4-羟基苄基烷基醚；步骤2,3,5-二烷基-4-羟基苄基烷基醚和1,3,5-三烷基苯在酸存在下进行反应,生成1,3,5-三烷基-2,4,6-三(3,5-二烷基-4-羟基苯甲基)苯。本发明大分子受阻酚类抗氧剂分子量大,抗迁移性好,同时具有优异的耐热氧老化性能,可广泛应用于橡胶、塑料等高分子材料材料的防老化。(The invention discloses a macromolecular hindered phenol antioxidant and a preparation method and application thereof, wherein the macromolecular hindered phenol antioxidant has the following structure: wherein R is 1 、R 2 、R 3 、R 4 And R 5 Independently a hydrocarbyl group having 1 to 20 carbons. The preparation method comprises the following steps: reacting 1, 2, 6-dialkyl phenol with paraformaldehyde in the presence of a catalyst and alcohol to generate 3, 5-dialkyl-4-hydroxybenzyl alkyl ether; and (3) reacting the 2, 3, 5-dialkyl-4-hydroxybenzyl alkyl ether with 1,3, 5-trialkylbenzene in the presence of acid to generate 1,3, 5-trialkyl-2, 4, 6-tri (3, 5-dialkyl-4-hydroxybenzyl) benzene. The macromolecular hindered phenol antioxidant has the advantages of large molecular weight, good migration resistance and excellent thermo-oxidative aging resistance, and can be widely applied to the anti-aging of macromolecular material materials such as rubber, plastic and the like.)

1. A macromolecular hindered phenol antioxidant characterized by having the structure:

wherein R is₁、R₂、R₃、R₄And R₅Independently a hydrocarbyl group having 1 to 20 carbons.

2. The macromolecular hindered phenolic antioxidant of claim 1, wherein R is₁And R₂Is one of methyl, ethyl, propyl, butyl, amyl and hexyl, and the R is₁And R₂The same or different.

3. The macromolecular hindered phenolic antioxidant of claim 1, wherein R is₃、R₄And R₅Is one of methyl, ethyl, propyl, butyl, amyl and hexyl, and the R is₃、R₄And R₅The same or different.

4. A preparation method of a macromolecular hindered phenol antioxidant is characterized by comprising the following steps:

reacting 1, 2, 6-dialkyl phenol with paraformaldehyde in the presence of a catalyst and alcohol to generate 3, 5-dialkyl-4-hydroxybenzyl alkyl ether;

and (3) reacting the 2, 3, 5-dialkyl-4-hydroxybenzyl alkyl ether with 1,3, 5-trialkylbenzene in the presence of acid to generate 1,3, 5-trialkyl-2, 4, 6-tri (3, 5-dialkyl-4-hydroxybenzyl) benzene.

5. The method for preparing a macromolecular hindered phenol antioxidant according to claim 4, wherein the 2, 6-dialkylphenol is one of 2, 6-dimethylphenol, 2, 6-di-tert-butylphenol, 2, 6-diisopropylphenol, 2-methyl-6-tert-butylphenol, 2-methyl-6-isopropylphenol, 2-isopropyl-6-tert-butylphenol; the catalyst is an amine catalyst; the alcohol is one or more of methanol, ethanol, propanol and butanol.

6. The method for preparing a macromolecular hindered phenol antioxidant according to claim 5, wherein the catalyst is one or more of N, N, N ', N' -tetramethylethylenediamine, dipropylamine and diethylamine; the molar ratio of the 2, 6-dialkyl phenol to the paraformaldehyde is 1:1-1:3, the amount of the alcohol is 2-5 times of the total mass of the 2, 6-dialkyl phenol and the paraformaldehyde, and the molar ratio of the catalyst to the 2, 6-dialkyl phenol is 1:8-1: 12; the reaction temperature of the step 1 is 80-120 ℃, and the reaction time is 4-10 h.

7. The method for preparing a hindered phenolic antioxidant as claimed in claim 4, wherein the 1,3, 5-trialkylbenzene is one of mesitylene, triethylbenzene, 1-methyl-3, 5-diethylbenzene, and 1, 3-dimethyl-5-ethylbenzene; the acid is sulfuric acid; the mass concentration of the sulfuric acid is 70-98%.

8. The method for preparing a macromolecular hindered phenol antioxidant according to claim 7, wherein the molar ratio of 1,3,5, -trialkylbenzene to 3, 5-dialkyl-4-hydroxybenzylalkyl ether is 1:3 to 1:5, and the molar ratio of the acid to 1,3,5, -trialkylbenzene is 1.5:1 to 3: 1; the reaction temperature of the step 2 is-5-5 ℃, and the reaction time is 1-5 h.

9. The method for preparing a macromolecular hindered phenol antioxidant according to claim 4, wherein the steps 1 and 2 are carried out under an inert gas atmosphere.

10. Use of a macromolecular hindered phenolic antioxidant according to any one of claims 1 to 3 in a polyethylene material.

11. The use of a macromolecular hindered phenol type antioxidant in a polyethylene material according to claim 10, wherein the polyethylene material comprises a high density polyethylene resin and a compounding aid; the mass ratio of the composite additive to the high-density polyethylene resin is 1-5%; the composite auxiliary agent comprises the macromolecular hindered phenol antioxidant.

12. The application of the macromolecular hindered phenol antioxidant in the polyethylene material according to claim 11, wherein the composite auxiliary agent further comprises an auxiliary antioxidant, a heat stabilizer and a rheological agent, and the mass ratio of the macromolecular hindered phenol antioxidant to the auxiliary antioxidant to the heat stabilizer to the rheological agent is 1: 0.5-1.5: 0.25-0.75: 0.05-0.15.

Technical Field

The invention relates to a macromolecular hindered phenol antioxidant, a preparation method and application thereof, belonging to the technical field of organic chemical synthesis.

Background

The polymer material is easily affected by oxygen, high temperature or illumination and other conditions in the processing or using process, so that oxidative degradation is generated, the mechanical property and the appearance of the material are poor, the service life is shortened, and the antioxidant can delay or inhibit the aging of the polymer material. Generally, a small amount of antioxidant (0.1-0.5%) is added into the high molecular material to play a role in delaying the aging of the polymer. The antioxidants commonly used are mainly amines, phenols, sulfur and phosphorus antioxidants, which can decompose hydroperoxides and are commonly used as secondary antioxidants, while amines and phenols antioxidants can terminate free radicals and are commonly used as primary antioxidants. Among them, amine antioxidants are generally easy to color and toxic, and generally are not suitable for use in plastic products, while hindered phenol antioxidants are receiving attention due to their excellent antioxidant properties, high thermal stability, and are not easy to color.

The antioxidant is added into the high polymer material, so that the aging of the material can be effectively inhibited, but the traditional antioxidant has low molecular weight, and is very easy to migrate and volatilize in the processing and using processes, so that the aging resistance of the antioxidant is poor, the service life of the high polymer material is reduced, and meanwhile, the antioxidant migrates to the surface of the material and diffuses to the surrounding environment in the using process, so that the surrounding environment is polluted. For example, antioxidants in food packaging materials enter food due to migration, and plastic cups enter water due to extraction due to prolonged contact with water. Therefore, it is an effective method to prepare an antioxidant having a high molecular weight and excellent extraction resistance.

Beer et al synthesized a macromolecular hindered phenol antioxidant poly [ (Z) -2- (non-8-enoyl) tridecane-2, 12-vinyl (35-di-t-butyl-4-hydroxy) cinnamic acid ], which was added to a polypropylene material separately from antioxidant 1010, and found that the antioxidant had excellent thermo-oxidative stability (Beer S, Teascale I, Brueggemann O. Immobilisation of Antioxidants via ADMET Polymerization for Enhanced Long-term Stabilization of Polyolefins [ J ]. European Polymer Journal,2013,49(12): 4257-.

Then Beer et al synthesized a macromolecular antioxidant with a 3, 5-di-tert-butyl hydroxyphenol structure by a step-wise addition polymerization of an alcohol olefin, which showed that it also had very high antioxidant properties (Beer S, Teasdale I, Brueggemann O. macromolecular inhibitors via thio-ene polymerization and the ir synthetic Effects [ J ]. Polymer Degradation & Stability,2014,110: 336. sup. 343).

Kasza et al synthesized a series of macromolecular antioxidants with different alkyl side chain lengths, and added them to polypropylene materials to evaluate their photoaging resistance. The results show that the Macromolecular antioxidant can effectively improve the light aging resistance of the polypropylene material, and the stronger the anti-migration of the antioxidant and the better the aging resistance as the molecular weight increases (Kasza G, Katar I A M, Attila N, et al. Synthesis of hybrid Polymer (ethylene) based Macromolecular inhibitors and Investigation of the Efficiency in Stabilization of Polyolefins [ J ]. Europan Polymer Journal,2015,68:609 617.).

Although the anti-migration and anti-extraction performance of the antioxidant can be effectively improved by the macromolecular hindered phenol antioxidant, and the anti-aging performance of the antioxidant is further improved, the process used for researching and developing the current macromolecular antioxidant is complex, the cost is high, large-scale industrial production cannot be realized, and the process is limited to the research stage, so that the development of the macromolecular hindered phenol antioxidant synthesis method which is simple in process, easy to obtain raw materials and low in cost is necessary.

Disclosure of Invention

The invention mainly aims to provide a macromolecular hindered phenol antioxidant, and a preparation method and application thereof, so as to overcome the defects of poor migration resistance and extraction resistance or complex process of hindered phenol antioxidants in the prior art.

In order to achieve the above object, the present invention provides a macromolecular hindered phenol antioxidant having the following structure:

wherein R is₁、R₂、R₃、R₄And R₅Independently a hydrocarbyl group having 1 to 20 carbons.

The macromolecular hindered phenol antioxidant of the invention is characterized in that R₁And R₂Is one of methyl, ethyl, propyl, butyl, amyl and hexyl, and the R is₁And R₂The same or different.

The macromolecular hindered phenol antioxidant of the invention is characterized in that R₃、R₄And R₅Is one of methyl, ethyl, propyl, butyl, amyl and hexyl, and the R is₃、R₄And R₅The same or different.

In order to achieve the above object, the present invention also provides a preparation method of the macromolecular hindered phenol antioxidant, which comprises the following steps:

reacting 1, 2, 6-dialkyl phenol with paraformaldehyde in the presence of a catalyst and alcohol to generate 3, 5-dialkyl-4-hydroxybenzyl alkyl ether;

and (3) reacting the 2, 3, 5-dialkyl-4-hydroxybenzyl alkyl ether with 1,3, 5-trialkylbenzene in the presence of acid to generate 1,3, 5-trialkyl-2, 4, 6-tri (3, 5-dialkyl-4-hydroxybenzyl) benzene.

The preparation method of the macromolecular hindered phenol antioxidant comprises the following steps of (1) preparing 2, 6-dialkyl phenol by using a solvent, wherein the 2, 6-dialkyl phenol is one of 2, 6-dimethyl phenol, 2, 6-di-tert-butyl phenol, 2, 6-diisopropyl phenol, 2-methyl-6-tert-butyl phenol, 2-methyl-6-isopropyl phenol and 2-isopropyl-6-tert-butyl phenol; the catalyst is an amine catalyst; the alcohol is one or more of methanol, ethanol, propanol and butanol.

The preparation method of the macromolecular hindered phenol antioxidant comprises the following steps of (1) preparing a catalyst, wherein the catalyst is one or more of N, N, N ', N' -tetramethyl-methyl-diamine, N, N, N ', N' -tetramethyl-ethylene-diamine, dipropyl-amine and diethylamine, and preferably diethylamine; the molar ratio of the 2, 6-dialkyl phenol to the paraformaldehyde is 1:1-1:3, the amount of the alcohol is 2-5 times of the total mass of the 2, 6-dialkyl phenol and the paraformaldehyde, and the molar ratio of the catalyst to the 2, 6-dialkyl phenol is 1:8-1: 12; the reaction temperature of the step 1 is 80-120 ℃, and the reaction time is 4-10 h.

The preparation method of the macromolecular hindered phenol antioxidant comprises the following steps of (1), 3, 5-trialkyl benzene is one of mesitylene, triethylbenzene, 1-methyl-3, 5-diethylbenzene and 1, 3-dimethyl-5-ethyl benzene; the acid is sulfuric acid; the mass concentration of the sulfuric acid is 70-98%.

The preparation method of the macromolecular hindered phenol antioxidant comprises the following steps of (1) preparing 1,3, 5-trialkyl benzene and 3, 5-dialkyl-4-hydroxybenzyl alkyl ether in a molar ratio of 1:3-1:5, and (1.5: 1-3: 1) preparing acid and 1,3, 5-trialkyl benzene in a molar ratio; the reaction temperature of the step 2 is-5-5 ℃, and the reaction time is 1-5 h.

The preparation method of the macromolecular hindered phenol antioxidant comprises the step 1 and the step 2 under the protection of inert gas.

In order to achieve the purpose, the invention further provides the application of the macromolecular hindered phenol antioxidant in the polyethylene material.

The invention relates to an application of a macromolecular hindered phenol antioxidant in a polyethylene material, wherein the polyethylene material comprises high-density polyethylene resin and a composite auxiliary agent; the mass ratio of the composite additive to the high-density polyethylene resin is 1-5%; the composite auxiliary agent comprises the macromolecular hindered phenol antioxidant.

The application of the macromolecular hindered phenol antioxidant in the polyethylene material is characterized in that the composite auxiliary agent further comprises an auxiliary antioxidant, a heat stabilizer and a rheological agent, wherein the mass ratio of the macromolecular hindered phenol antioxidant to the auxiliary antioxidant to the heat stabilizer to the rheological agent is 1: 0.5-1.5: 0.25-0.75: 0.05-0.15.

The invention has the beneficial effects that:

the macromolecular hindered phenol antioxidant is synthesized by simple electrophilic substitution reaction, and has the advantages of simple process, mild conditions, easily obtained raw materials and lower cost.

The hindered phenol antioxidant has higher molecular weight, is not easy to generate migration loss, has good migration resistance and solvent extraction resistance with high polymer materials, can be applied to the anti-aging of various high polymer materials, and has excellent antioxidation.

Drawings

FIG. 1 is an IR spectrum of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene obtained in example 1;

FIG. 2 is a nuclear magnetic hydrogen spectrum of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene obtained in example 1.

Detailed Description

The present invention is described in detail below with reference to specific examples, but the use and purpose of these exemplary embodiments are merely to exemplify the present invention, and do not set forth any limitation on the actual scope of the present invention in any form, and the scope of the present invention is not limited thereto.

The invention provides a macromolecular hindered phenol antioxidant, and a preparation method of the macromolecular hindered phenol antioxidant comprises the following steps:

reacting 1, 2, 6-dialkyl phenol with paraformaldehyde in the presence of a catalyst and alcohol to generate 3, 5-dialkyl-4-hydroxybenzyl alkyl ether;

and (3) reacting the 2, 3, 5-dialkyl-4-hydroxybenzyl alkyl ether with 1,3, 5-trialkylbenzene in the presence of acid to generate 1,3, 5-trialkyl-2, 4, 6-tri (3, 5-dialkyl-4-hydroxybenzyl) benzene.

The specific process of the preparation method of the invention can be seen in the following formula I:

wherein two alkyl groups in the 2, 6-dialkyl phenol are respectively R₁And R₂，R₁、R₂Independently a hydrocarbon group having 1 to 20 carbons, preferably methyl, ethyl, propylOne of the radicals, butyl, pentyl and hexyl, R₁And R₂May be the same or different. More preferably, the 2, 6-dialkylphenol is one of 2, 6-dimethylphenol, 2, 6-di-tert-butylphenol, 2, 6-diisopropylphenol, 2-methyl-6-tert-butylphenol, 2-methyl-6-isopropylphenol, 2-isopropyl-6-tert-butylphenol.

The paraformaldehyde in the present invention is not particularly limited, and may be a commercially available product. The molecular formula of paraformaldehyde is HO- (CH)₂O)_n-H, wherein n-10-100.

The catalyst used in the step 1 is an amine catalyst, preferably one or more of N, N, N ', N' -tetramethylethylenediamine, dipropylamine and diethylamine, and more preferably diethylamine; wherein the alcohol as solvent can be one or more of methanol, ethanol, propanol and butanol.

In one embodiment, the molar ratio of 2, 6-dialkylphenol to paraformaldehyde is from 1:1 to 1:3, the amount of alcohol is from 2 to 5 times the total mass of 2, 6-dialkylphenol and paraformaldehyde, and the molar ratio of catalyst to 2, 6-dialkylphenol is from 1:8 to 1: 12.

Dissolving 2, 6-dialkyl phenol and paraformaldehyde in alcohol, adding catalyst diethylamine, and reacting under the protection of inert gas. The reaction temperature is, for example, 80 to 120 ℃, the reaction time is, for example, 4 to 10 hours, the reaction system is cooled to room temperature after the reaction is finished, the mixed system is filtered under negative pressure to obtain yellow solid, and the yellow solid is dried to constant weight under the vacuum condition of room temperature to 60 ℃ to obtain 3, 5-dialkyl-4-hydroxybenzyl alkyl ether, and as an embodiment, 3, 5-dialkyl-4-hydroxybenzyl methyl ether is obtained.

Then, dissolving 1,3, 5-trialkyl benzene in an organic solvent, dropping the solution of the obtained 3, 5-dialkyl-4-hydroxybenzyl alkyl ether in the organic solvent and a sulfuric acid solution with a certain concentration at a low temperature under the protection of inert gas, and keeping the reaction system to react for a certain time at a low temperature, wherein the reaction temperature can be-5-5 ℃ and the reaction time can be 1-5 hours. And after the reaction is finished, pouring the mixed solution after the reaction into a separating funnel, collecting upper-layer liquid, neutralizing the upper-layer liquid by using a saturated sodium bicarbonate aqueous solution, washing the upper-layer liquid to be neutral, carrying out reduced pressure distillation, collecting a solid sample, and drying the solid sample to constant weight under the vacuum condition at room temperature of 60 ℃ below zero to obtain the macromolecular hindered phenol antioxidant. Wherein the organic solvent can be dichloromethane, and the amount of the organic solvent is 5-10 times of the total mass of the reactants (namely the sum of the mass of the 1,3, 5-trialkyl benzene and the mass of the 3, 5-dialkyl-4-hydroxybenzyl alkyl ether).

Wherein three substituents of the 1,3, 5-trialkyl benzene are respectively R₃、R₄And R₅，R₃、R₄And R₅Independently a hydrocarbyl group having 1 to 20 carbons; as a preferred embodiment, R₃、R₄And R₅Is one of methyl, ethyl, propyl, butyl, amyl and hexyl, R₃、R₄And R₅The groups may be the same or different, and the present invention is not particularly limited. More preferably, the 1,3, 5-trialkylbenzene of the present invention is one of mesitylene, triethylbenzene, 1-methyl-3, 5-diethylbenzene and 1, 3-dimethyl-5-ethylbenzene.

The sulfuric acid used in the step is high-concentration sulfuric acid, and the mass concentration is generally 70-98%. In one embodiment, the molar ratio of 1,3,5, -trialkylbenzene to 3, 5-dialkyl-4-hydroxybenzylalkyl ether is from 1:3 to 1:5 and the molar ratio of sulfuric acid to 1,3,5, -trialkylbenzene is from 1.5:1 to 3: 1.

The inert gas in the present invention is not particularly limited, and may be nitrogen gas, argon gas, or the like.

In one embodiment, the amount of the saturated aqueous solution of sodium bicarbonate is 0.8 to 1.5 times of the total volume of the organic solvent

The macromolecular hindered phenol antioxidant obtained by the method has higher molecular weight, is not easy to generate migration loss, has good migration resistance and solvent extraction resistance with a macromolecular material, can be applied to the anti-aging of various macromolecular materials, and has excellent antioxidation.

The macromolecular hindered phenol antioxidant can be used for high-density polyethylene resin to improve the oxidation resistance of the resin.

In the granulation section of the high-density polyethylene production, a composite auxiliary agent with the mass ratio of 1-5% to the high-density polyethylene resin is added, wherein the composite auxiliary agent is preferably prepared by mixing a main antioxidant, an auxiliary antioxidant, a heat stabilizer and a rheological agent according to the weight ratio of 1: 0.5-1.5: 0.25-0.75: 0.05-0.15 percent by mass.

The main antioxidant is the macromolecular hindered phenol antioxidant obtained by the invention. The auxiliary antioxidant is one or a mixture of any more of bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, tris (2, 4-di-tert-butylphenyl) phosphite, dilauryl thiodipropionate and distearyl thiodipropionate. The heat stabilizer can be a metal soap heat stabilizer, and is preferably one or a mixture of any two of calcium stearate, magnesium stearate, zinc stearate and aluminum stearate. The rheological agent may be a fluorine rheological body.

The polyethylene resin mixed with the composite additive has good migration resistance and solvent extraction resistance, and has excellent oxidation resistance.

The technical solution of the present invention will be described in detail by specific examples.

Example 1

Synthesis of 3, 5-dimethyl-4-hydroxybenzyl methyl ether: accurately weighed 12.6g of 2, 6-dimethylphenol, 3.0g of paraformaldehyde, 0.75g of diethylamine were dissolved in 55mL of methanol, N₂Reacting at 100 ℃ for 6h under protection, cooling to room temperature after the reaction is finished, filtering the mixed system under negative pressure, and drying at 50 ℃ under vacuum condition to constant weight to obtain yellow solid.

Synthesis of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene: accurately weighing 0.7g of mesitylene, dissolving the mesitylene in 5mL of dichloromethane, slowly dropwise adding 20mL of dichloromethane solution containing 5g of 3, 5-dimethyl-4-hydroxybenzyl methyl ether at 0 ℃ under ice bath, then slowly dropwise adding 3mL of concentrated sulfuric acid with the mass fraction of 85%, keeping the reaction system at 0-3 ℃ for reacting for 2h, pouring the mixed solution after reaction into a separating funnel, collecting the upper layer liquid, neutralizing with saturated sodium bicarbonate aqueous solution, washing with water to be neutral, taking the lower layer dichloromethane solution for pressure distillation, and drying the obtained solid sample under the vacuum condition of 50 ℃ to constant weight to obtain a light yellow solid. The FT-IR spectrum of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene is shown in FIG. 1, wherein: 3644.54cm^-1Is treated with phenolStretching vibration of hydroxyl group, 2958.03cm^-1And 2872.63cm^-1Stretching vibration of the base at 1433.70cm^-1In-plane bending vibration peak at methyl group, 1152.15cm^-1And 1119.78cm^-1The peak is the in-plane bending vibration peak of the phenolic hydroxyl group. Process for preparing 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene¹The H NMR spectrum is shown in FIG. 2, wherein: at 2.15ppm, -CH adjacent to the phenolic hydroxyl group₃Absorption peak of upper hydrogen atom at 2.18ppm is-CH on mesitylene₃Absorption peak of upper hydrogen atom at 3.96ppm is-CH₂-absorption peak of upper hydrogen atom; the hydrogen atom on the benzene ring showed an absorption peak at 6.74 ppm. From the above characterization results, it can be seen that the molecular structure of the antioxidant obtained by the method of the present invention is consistent with the theoretical structure, and the macromolecular hindered phenol antioxidant of formula I can be synthesized by the method of the present invention.

1,3, 5-trimethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene, tris (2, 4-di-tert-butylphenyl) phosphite, calcium stearate, zinc stearate, fluorine rheological agent were mixed in the following ratio of 1: 1: putting the mixture into a high-speed mixing roll according to the mass ratio of 0.5:0.5:0.5, stirring the mixture at room temperature, mixing the mixture for 5 to 20 minutes, and then sending the mixture into a powder extruder for extrusion to obtain the composite auxiliary agent containing the antioxidant 1,3, 5-trimethyl-2, 4,6- (3, 5-dimethyl-4-hydroxybenzyl) benzene.

In the granulating section of polyethylene, 0.35% of composite auxiliary agent is added, and the mixture is melted, extruded, drawn and granulated by an extruder. The polyethylene resin was then tested for melt flow rate, mechanical properties, and oxidation induction period. The results of the physical property test of the polyethylene resin are shown in Table 1.

Example 2

The difference from example 1 is that the experimental time during the synthesis of 0.7g of mesitylene was changed to 1.0g of mesitylene, 1,3, 5-triethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene was changed to 5h, the amount of sulfuric acid was changed to 4.5ml, and other experimental methods and experimental conditions were the same as in example 1.

Example 3

The difference from example 1 is that the experimental time during the synthesis of 0.7g of mesitylene was changed to 0.9g of 1-methyl-3, 5-diethylbenzene, 1-methyl-3, 5-diethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene was changed to 5 hours, and the other experimental methods and experimental conditions were the same as in example 1.

Example 4

The difference from example 1 is that 0.7g of mesitylene was changed to 0.8g of 1, 3-dimethyl-5-ethylbenzene, and the other experimental methods and experimental conditions were the same as in example 1.

Example 5

3, 5-diisopropyl-4-hydroxybenzyl methyl ether synthesis: accurately weighed 14.1g of 2, 6-diisopropylphenol, 4.5g of paraformaldehyde, 0.9g of diethylamine were dissolved in 70mL of methanol, N₂Reacting at 120 ℃ for 4 hours under protection, cooling to room temperature after the reaction is finished, filtering the mixed system under negative pressure, and drying at 50 ℃ under vacuum condition to constant weight to obtain yellow solid.

Synthesis of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-diisopropyl-4-hydroxybenzyl) benzene: accurately weighing 0.7g of mesitylene, dissolving the mesitylene in 5mL of dichloromethane, slowly dropwise adding 25mL of dichloromethane solution containing 8g of 3, 5-diisopropyl-4-hydroxybenzyl methyl ether at 0 ℃ under ice bath, then slowly dropwise adding 5mL of concentrated sulfuric acid with the mass fraction of 85%, keeping the reaction system at 0-3 ℃ for reacting for 6h, pouring the mixed solution after reaction into a separating funnel, collecting the upper layer liquid, neutralizing with saturated sodium bicarbonate aqueous solution, washing with water to be neutral, taking the lower layer dichloromethane solution for pressure distillation, and drying the obtained solid sample under the vacuum condition of 50 ℃ to constant weight to obtain a light yellow solid.

1,3, 5-trimethyl-2, 4, 6-tris (3, 5-diisopropyl-4-hydroxybenzyl) benzene, tris (2, 4-di-tert-butylphenyl) phosphite, calcium stearate, zinc stearate, fluorine rheological agent were mixed in the following ratio of 1: 1: putting the mixture into a high-speed mixing roll according to the mass ratio of 0.5:0.5:0.5, stirring the mixture at room temperature, mixing the mixture for 5 to 20 minutes, and then sending the mixture into a powder extruder for extrusion to obtain the composite additive containing the antioxidant 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene.

In the granulating section of polyethylene, 0.35% of composite auxiliary agent is added, and the mixture is melted, extruded, drawn and granulated by an extruder. The polyethylene resin was then tested for melt flow rate, mechanical properties, and oxidation induction period. The results of the physical property test of the polyethylene resin are shown in Table 1.

Example 6

The difference from example 5 is that 0.7g of mesitylene is changed to 1.0g of mesitylene, the amount of 3, 5-diisopropyl-4-hydroxybenzyl methyl ether used in the synthesis of 1,3, 5-triethyl-2, 4, 6-tris (3, 5-diisopropyl-4-hydroxybenzyl) benzene is changed to 10g, the amount of sulfuric acid used is changed to 6ml, and other experimental methods and experimental conditions are the same as those in example 5.

Example 7

The difference from example 5 is that the amount of 3, 5-diisopropyl-4-hydroxybenzyl methyl ether used in the synthesis of 0.7g of mesitylene was changed to 0.9g of 1-methyl-3, 5-diethylbenzene, 1-methyl-3, 5-diethyl-2, 4, 6-tris (3, 5-diisopropyl-4-hydroxybenzyl) benzene was changed to 10g, the amount of sulfuric acid was changed to 6ml, and the other experimental methods and experimental conditions were the same as in example 5.

Example 8

The difference from example 5 is that 0.7g of mesitylene was changed to 0.8g of 1, 3-dimethyl-5-ethylbenzene, and the amount of 3, 5-diisopropyl-4-hydroxybenzyl methyl ether used in the synthesis of 1-methyl-3, 5-diethyl-2, 4, 6-tris (3, 5-diisopropyl-4-hydroxybenzyl) benzene was changed to 10g, and the other experimental methods and experimental conditions were the same as in example 5.

Example 9

3-methyl-5-isopropyl-4-hydroxybenzyl methyl ether synthesis: accurately weighed 13g of 2-methyl-6-isopropylphenol, 4.5g of paraformaldehyde and 0.9g of diethylamine were dissolved in 70mL of methanol, and N was₂Reacting at 120 ℃ for 4 hours under protection, cooling to room temperature after the reaction is finished, filtering the mixed system under negative pressure, and drying at 50 ℃ under vacuum condition to constant weight to obtain yellow solid.

Synthesis of 1,3, 5-triethyl-2, 4, 6-tris (3-methyl-5-isopropyl-4-hydroxybenzyl) benzene: accurately weighing 1.0g of sym-triethylbenzene, dissolving in 5mL of dichloromethane, slowly dropwise adding 30mL of dichloromethane solution containing 10g of 3-methyl-5-isopropyl-4-hydroxybenzyl methyl ether at 0 ℃ under ice bath, then slowly dropwise adding 5mL of concentrated sulfuric acid with the mass fraction of 85%, keeping the reaction system at 0-3 ℃ for reacting for 6h, pouring the reacted mixed solution into a separating funnel, collecting the upper layer liquid, neutralizing with saturated sodium bicarbonate aqueous solution, washing with water to be neutral, taking the lower layer dichloromethane solution for pressure distillation, and drying the obtained solid sample under the vacuum condition of 50 ℃ to constant weight to obtain a light yellow solid.

1,3, 5-triethyl-2, 4, 6-tris (3-methyl-5-isopropyl-4-hydroxybenzyl) benzene, tris (2, 4-di-tert-butylphenyl) phosphite, calcium stearate, zinc stearate, fluorine rheology control agent according to the following ratio of 1: 1: putting the mixture into a high-speed mixing roll according to the mass ratio of 0.5:0.5:0.5, stirring the mixture at room temperature, mixing the mixture for 5 to 20 minutes, and then sending the mixture into a powder extruder for extrusion to obtain the composite auxiliary agent containing the antioxidant 1,3, 5-trimethyl-2, 4,6- (3, 5-dimethyl-4-hydroxybenzyl) benzene.

In the granulating section of polyethylene, 0.35% of composite auxiliary agent is added, and the mixture is melted, extruded, drawn and granulated by an extruder. The polyethylene resin was then tested for melt flow rate, mechanical properties, and oxidation induction period. The results of the physical property test of the polyethylene resin are shown in Table 1.

Example 10

The difference from example 9 is that 13g of 2-methyl-6-isopropylphenol was changed to 13.9g of 2-methyl-6-tert-butylphenol, and the other experimental procedures and experimental conditions were the same as in example 9.

Example 11

The difference from example 9 is that 13g of 2-methyl-6-isopropylphenol was changed to 14.5g of 2-isopropyl-6-tert-butylphenol, and the other experimental procedures and experimental conditions were the same as in example 9.

Example 12

The difference from example 9 is that 13g of 2-methyl-6-isopropylphenol was changed to 15g of 2, 6-di-t-butylphenol, and the other experimental methods and experimental conditions were the same as in example 9.

Comparative example 1

Mixing pentaerythritol [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], tris (2, 4-di-tert-butylphenyl) phosphite, calcium stearate, zinc stearate and a fluorine rheological agent according to the weight ratio of 1: 1: putting the mixture into a high-speed mixing roll according to the mass ratio of 0.5:0.5:0.5, stirring at room temperature, mixing for 5-20 minutes, and then sending the mixture into a powder extruder for extrusion to obtain the composite auxiliary agent containing the antioxidant [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester.

In the pelletizing section of polyethylene (which was the same as that used in examples 1-12), 0.35% of compounding agent was added, and melt-extruded by an extruder, drawn into a strand and pelletized. The polyethylene resin was then tested for melt flow rate, mechanical properties, and oxidation induction period. The results of the physical property test of the polyethylene resin are shown in Table 1.

Comparative example 2

In the pelletization section of polyethylene (which was the same as that used in examples 1 to 12), without adding any auxiliary agent, melt-extruded through an extruder, drawn and pelletized. The polyethylene resin was then tested for melt flow rate, mechanical properties, and oxidation induction period. The results of the physical property test of the polyethylene resin are shown in Table 1.

TABLE 1 analytical test results for polyethylene resins

As can be seen from the data in Table 1, the polyethylene resin in comparative example 2 without the compound additive has lower performance indexes, the polyethylene resin in comparative example 1 with the commercial antioxidant [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester has improved performance indexes, but compared with the series of macromolecular hindered phenol antioxidants synthesized by the invention, the series of macromolecular hindered phenol antioxidants has more excellent performance, wherein the oxidation induction period of the polyethylene resin with the antioxidant 1-methyl-3, 5-diethyl-2, 4, 6-tris (3, 5-dimethyl-4-hydroxybenzyl) benzene is longest, is 173.6min, and shows that the polyethylene resin has the best thermal oxidation aging resistance.

The present invention is capable of other embodiments, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.