阅读说明：本技术 胺类抗氧剂及其制备方法与应用 (Amine antioxidant and preparation method and application thereof ) 是由 王玉如 任鹤 王登飞 何书艳 赵增辉 闫义彬 牛娜 吴双 高宇新 宋磊 张瑞 于 2020-04-10 设计创作，主要内容包括：本发明公开一种胺类抗氧剂及其制备方法与应用,该胺类抗氧剂具有以下结构：其中,n为1-20的整数。该制备方法包括如下步骤：步骤1,正烷基胺与丙烯酸甲酯反应得到式Ⅰ化合物；步骤2,式Ⅰ化合物与二氯亚砜反应生成式Ⅱ化合物；步骤3,式Ⅱ化合物与对苯二胺反应生成式Ⅲ化合物；步骤4,式Ⅲ化合物与β-萘酚反应生成式Ⅳ胺类抗氧剂。本发明得到的胺类抗氧剂为浅黄色粉末,无味,通过红外光谱和核磁碳谱的表征结果证明该抗氧剂的分子结构与理论结构一致。该方法中未使用价格昂贵的催化剂,反应条件温和,且原料便宜易得,具有很好的经济性。(The invention discloses an amine antioxidant and a preparation method and application thereof, wherein the amine antioxidant has the following structure: wherein n is an integer of 1 to 20. The preparation method comprises the following steps: step 1, reaction of n-alkylamine with methyl acrylateTo obtain a compound of formula I; step 2, reacting the compound shown in the formula I with thionyl chloride to generate a compound shown in the formula II; step 3, reacting the compound of the formula II with p-phenylenediamine to generate a compound of a formula III; and 4, reacting the compound shown in the formula III with beta-naphthol to generate the amine antioxidant shown in the formula IV. The amine antioxidant obtained by the invention is light yellow powder, is tasteless, and has a molecular structure consistent with a theoretical structure as proved by characterization results of infrared spectroscopy and nuclear magnetic carbon spectrum. The method does not use expensive catalyst, has mild reaction conditions, cheap and easily obtained raw materials and good economical efficiency.)

1. An amine antioxidant, characterized in that the amine antioxidant has the following structure:

wherein n is an integer of 1 to 20.

2. The amine antioxidant as defined in claim 1, wherein the amine antioxidant has a melting point of 106-110 ℃.

3. The preparation method of the amine antioxidant is characterized by comprising the following steps:

step 1, reacting n-alkylamine with methyl acrylate to obtain a compound shown in a formula I;

step 2, reacting the compound shown in the formula I with thionyl chloride to generate a compound shown in the formula II;

step 3, reacting the compound of the formula II with p-phenylenediamine to generate a compound of a formula III;

step 4, reacting the compound shown in the formula III with beta-naphthol to generate an amine antioxidant shown in the formula IV;

wherein n is an integer of 1 to 20.

4. The method for preparing the amine antioxidant according to claim 3, wherein the molar ratio of the n-alkylamine to the methyl acrylate in the step 1 is 1:2 to 1:10, the reaction temperature is 25 ℃ to 60 ℃, and the reaction time is 12 to 24 hours; after the reaction is finished, carrying out reduced pressure distillation to obtain the compound shown in the formula I.

5. The preparation method of the amine antioxidant as claimed in claim 3, wherein the molar ratio of the compound of formula I in the step 2 to thionyl chloride is 1: 1.5-1: 5, the reaction temperature is 25-50 ℃, and the reaction time is 3-6 h; and 2, carrying out the reaction under the protection of nitrogen, and after the reaction is finished, carrying out reduced pressure distillation to obtain a compound shown in the formula II.

6. The preparation method of the amine antioxidant as claimed in claim 3, wherein the molar ratio of p-phenylenediamine to the compound of formula II in the step 3 is 3.5: 1-2: 1, the reaction temperature is-5 ℃ to 30 ℃, and the reaction time is 18-24 h; and 3, carrying out the reaction under the protection of nitrogen, and carrying out vacuum filtration after the reaction is finished to obtain the compound shown in the formula III.

7. The preparation method of the amine antioxidant according to claim 3, wherein the molar ratio of the compound of formula III to the beta-naphthol in step 4 is 1: 2-1: 5, the catalyst is iodine, and the molar ratio of the amount of the catalyst to the compound of formula III is 1: 10-1: 15; the reaction temperature is 150-220 ℃, and the reaction time is 12-18 h; and after the reaction is finished, carrying out vacuum filtration to obtain a compound shown in the formula IV.

8. The method for preparing amine antioxidant as claimed in claim 5, wherein thionyl chloride in step 2 is added dropwise to the compound of formula I in batches for reaction.

9. Use of the amine antioxidant according to claim 1 or 2 in polyethylene.

10. The use of amine antioxidants in polyethylene according to claim 9, wherein said amine antioxidants are added in a mass ratio of 0.05 to 0.15 wt% to polyethylene, 0.05 to 0.15 wt% of auxiliary antioxidants, and 0.025 to 0.075 wt% of heat stabilizers in the granulation section of polyethylene production.

11. The use of amine antioxidants according to claim 10 in polyethylene, wherein said secondary antioxidants are selected from the group consisting of bis (2, 4-di-t-butylphenyl) pentaerythritol diphosphite, tris (2, 4-di-t-butylphenyl) phosphite, dilauryl thiodipropionate and distearyl thiodipropionate, or a mixture of any of them.

12. The use of the amine antioxidant as claimed in claim 10, wherein the heat stabilizer is one or a mixture of any of calcium stearate, magnesium stearate, zinc stearate and aluminum stearate.

Technical Field

The invention relates to an antioxidant, in particular to an amine antioxidant for polyethylene, a preparation method and application thereof, belonging to the technical field of organic chemical synthesis.

Background

Polyethylene materials are widely applied to various fields of production and life, but are aged and degraded under the action of light, oxygen, heavy metal ions and the like in the using process, so that the using performance is lost. At present, the addition of antioxidants to polyethylene materials is the most effective approach. The common antioxidants mainly comprise phenolic antioxidants and amine antioxidants, wherein the phenolic antioxidants are widely applied to polyethylene materials due to light color and excellent oxidation resistance.

In recent years, with the increase of the demand of polyethylene, the market of polyethylene is continuously increased, and the production of high-end polyethylene is the mainstream, however, the phenolic antioxidant has a large molecular weight, and has poor compatibility with polyethylene materials in the processing process, so that the antioxidant performance is reduced, and the production requirement cannot be met. Therefore, hindered amine antioxidants with excellent performance and good compatibility with polyethylene materials are developed.

Patent CN108164432A reports that the hindered amine antioxidant is prepared by first performing substitution reaction on halogenated aniline compound and acyl halide compound to generate intermediate, and then performing addition reaction on the intermediate (I) and chain fatty amine to generate intermediate (II); and finally, carrying out substitution reaction on the intermediate (II) and the 2-naphthylamine compound to generate the hindered amine antioxidant. The use of expensive XPhos and Pd in the synthesis₂(dba)₃The catalyst and the substances are purified and separated by adopting a column chromatography method and a solution extraction method, so that the production efficiency is low and the production cost is high.

Disclosure of Invention

The invention mainly aims to provide an amine antioxidant, and a preparation method and application thereof, so as to overcome the defects of complex preparation process, high production cost and the like of the amine antioxidant in the prior art.

In order to achieve the above object, the present invention provides an amine antioxidant having the following structure:

wherein n is an integer of 1 to 20.

The amine antioxidant has a melting point of 106-110 ℃.

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

step 1, reacting n-alkylamine with methyl acrylate to obtain a compound shown in a formula I;

step 2, reacting the compound shown in the formula I with thionyl chloride to generate a compound shown in the formula II;

step 3, reacting the compound of the formula II with p-phenylenediamine to generate a compound of a formula III;

step 4, reacting the compound shown in the formula III with beta-naphthol to generate an amine antioxidant shown in the formula IV;

wherein n is an integer of 1 to 20.

The preparation method of the amine antioxidant comprises the following steps of 1: 2-1: 10 of molar ratio of n-alkylamine to methyl acrylate in the step 1, 25-60 ℃ of reaction temperature and 12-24 hours of reaction time; after the reaction is finished, carrying out reduced pressure distillation to obtain the compound shown in the formula I.

The preparation method of the amine antioxidant comprises the following steps of (1) preparing a compound of formula I in the step 2, wherein the molar ratio of the compound of formula I to thionyl chloride is 1: 1.5-1: 5, the reaction temperature is 25-50 ℃, and the reaction time is 3-6 hours; and 2, carrying out the reaction under the protection of nitrogen, and after the reaction is finished, carrying out reduced pressure distillation to obtain a compound shown in the formula II.

The preparation method of the amine antioxidant comprises the following steps of (1) enabling the molar ratio of p-phenylenediamine to a compound of a formula II in the step (3) to be 3.5: 1-2: 1, enabling the reaction temperature to be-5-30 ℃ and the reaction time to be 18-24 hours; and 3, carrying out the reaction under the protection of nitrogen, and carrying out vacuum filtration after the reaction is finished to obtain the compound shown in the formula III.

The preparation method of the amine antioxidant comprises the following steps of (1) enabling the molar ratio of the compound of the formula III to the beta-naphthol to be 1: 2-1: 5 in the step 4, enabling the catalyst to be iodine, and enabling the molar ratio of the dosage of the catalyst to the compound of the formula III to be 1: 10-1: 15; the reaction temperature is 150-220 ℃, and the reaction time is 12-18 h; and after the reaction is finished, carrying out vacuum filtration to obtain a compound shown in the formula IV.

The preparation method of the amine antioxidant comprises the step 2 of dropwise adding thionyl chloride into a compound shown in the formula I in batches for reaction.

In order to achieve the purpose, the invention further provides the application of the amine antioxidant in polyethylene.

In the granulation section of polyethylene production, 0.05-0.15 wt% of the amine antioxidant, 0.05-0.15 wt% of the auxiliary antioxidant and 0.025-0.075 wt% of the heat stabilizer are added.

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 is one or a mixture of any more of calcium stearate, magnesium stearate, zinc stearate and aluminum stearate.

The invention has the beneficial effects that:

the amine antioxidant has the advantages of cheap and easily-obtained raw materials, simple purification process and high production efficiency, can effectively solve the problems of high product cost and difficult product purification caused by the raw materials and the catalyst in the prior art, has mild reaction conditions, and can realize the separation of products only by reduced pressure distillation and vacuum filtration.

Drawings

FIG. 1 is a nuclear magnetic carbon spectrum of 3,3' -dodecaamino-bis- (N- (4-naphthylamino) phenyl) propionamide;

FIG. 2 is a mass spectrum of 3,3' -dodecaamino-bis- (N- (4-naphthylamino) phenyl) propionamide;

FIG. 3 is an IR spectrum of 3,3' -dodecamino-bis- (N- (4-naphthylamino) phenyl) propionamide.

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 discloses a preparation method of an amine antioxidant, which comprises the following steps:

step 1, reacting n-alkylamine with methyl acrylate to obtain a compound shown in a formula I;

step 2, reacting the compound shown in the formula I with thionyl chloride to generate a compound shown in the formula II;

step 3, reacting the compound of the formula II with p-phenylenediamine to generate a compound of a formula III;

step 4, reacting the compound shown in the formula III with beta-naphthol to generate an amine antioxidant shown in the formula IV;

wherein the n-alkylamine is a linear alkylamine having a molecular formula of C_nH_2n+1NH₂And n is an integer of 1 to 20. Firstly, dissolving n-alkylamine in an organic solvent, dropwise adding methyl acrylate at room temperature, and carrying out Michael addition reaction at the reaction temperature of 25-60 ℃ for 12-24 hours; after the reaction is finished, carrying out reduced pressure distillation to obtain the compound shown in the formula I. Wherein the molar ratio of the n-alkylamine to the methyl acrylate is 1: 2-1: 10, the organic solvent is methanol, for example, and the amount of the organic solvent is 2-5 times of the total mass of the reaction raw materials (the total mass of the n-alkylamine and the methyl acrylate).

And then, dissolving the compound shown in the formula I in an organic solvent, and dropwise adding thionyl chloride at room temperature in batches to perform acylation reaction, wherein the reaction temperature is 25-50 ℃, and the reaction time is 3-6 h. After the reaction is finished, carrying out reduced pressure distillation to obtain the compound shown in the formula II. Wherein the molar ratio of the compound of formula I to thionyl chloride is 1: 1.5-1: 5, the organic solvent is not particularly limited in the invention, and chloroform is preferred. The dosage of the organic solvent is 3-10 times of the total mass of the reaction raw materials (the total mass of the compound shown in the formula I and the thionyl chloride).

And then, dissolving p-phenylenediamine in an organic solvent, dropwise adding the compound of the formula II under the protection of inert gas, carrying out dropwise adding operation at a low temperature, preferably at a temperature of-5 ℃, then carrying out amidation reaction, preferably at room temperature for 18-24 h, and carrying out vacuum filtration after the reaction is finished to obtain the compound of the formula III. Wherein, the molar ratio of the p-phenylenediamine to the compound of the formula II is 3.5: 1-2: 1, the organic solvent is not particularly limited in the invention, and benzene is preferred. The dosage of the organic solvent is 2-5 times of the total mass of the reaction raw materials (the total mass of the p-phenylenediamine and the compound of the formula II).

And finally, dissolving the compound shown in the formula III and beta-naphthol in an organic solvent, taking iodine as a catalyst, carrying out high-temperature reflux reaction at the preferable reaction temperature of 150-220 ℃ for 12-18 h, and carrying out vacuum filtration after the reaction is finished to obtain the amine antioxidant shown in the formula IV. Wherein, the molar ratio of the compound of the formula III and the beta-naphthol is 1: 2-1: 5, the molar ratio of the used amount of the catalyst to the compound of the formula III is 1: 10-1: 15, the organic solvent is not particularly limited, and benzene is preferred. The dosage of the organic solvent is 5-10 times of the total mass of the reaction raw materials (the total mass of the compound shown in the formula III and the beta-naphthol).

The amine antioxidant of formula IV obtained by the method has the following structure:

wherein n is an integer of 1 to 20.

The amine antioxidant obtained by the invention is light yellow powder, has no smell, has a melting point of 106-.

The amine antioxidant has the advantages of cheap and easily-obtained raw materials, mild reaction conditions, simple purification process, high production efficiency and easy industrial production, and can realize effective separation of products only by reduced pressure distillation and vacuum filtration.

The technical solution of the present invention is described in detail by the following specific examples.

Example 1

(1) Synthesis of dimethyl-3, 3'- (dodecylamino) dipropionate dimethyl 3,3' - (dodecylamino) dipropionate (formula I): 9.25g of dodecylamine is accurately weighed and dissolved in 78.3g of methanol, 43g of methyl acrylate is slowly dripped under stirring at the temperature of 25 ℃, and the reaction is carried out for 24 hours at the constant temperature of 40 ℃. After the reaction, the unreacted methyl acrylate and the solvent methanol are distilled out by reduced pressure distillation, and the dimethyl-3, 3' - (dodecylamino) dipropionate is obtained.

(2) Synthesis of 3,3' - (dodecamino) dipropionyl chloride (formula ii): accurately weighing 3.29g of dimethyl 3,3' - (dodecylamino) dipropionate, dissolving in 30.6g of trichloromethane, and carrying out N reaction at 25 DEG C₂Under the condition, 6ml of thionyl chloride is added in batches, and after the addition is finished, the reaction is heated to 40 ℃ and reacts for 1 hour at constant temperature. After the reaction, thionyl chloride and chloroform are removed by reduced pressure distillation, and 3,3' - (dodecyl) dipropyl chloride is obtained.

(3) Synthesis of 3,3' - (dodecamino) -bis- (N- (4-aminophenyl) propionamide) (formula iii): firstly, the device is pumped and discharged by double-row pipes, the reaction system is a nitrogen environment, the temperature of the system is controlled to be 0-5 ℃, 3.24g of p-phenylenediamine is accurately weighed and dissolved in 16g of benzene, the temperature is 0 ℃, and N is added₂Slowly dripping 3.7g of 3,3' - (dodecaamino) dipropyl chloride under the condition, heating the reaction system to 25 ℃ after complete dripping, and reacting for 24 hours at constant temperature. And (3) carrying out vacuum filtration on the mixture after reaction to obtain the 3,3' - (dodecaamino) -bis- (N- (4-aminophenyl) propionamide).

(4) Synthesis of 3,3' -dodecaamino-bis- (N- (4-naphthylamino) phenyl) propionamide (formula iv): accurately weighed were 4.32g of beta-naphthol, 5.09g of 3,3' - (dodecamino) -bis- (N- (4-aminophenyl) propionamide) and 0.25g I₂Dissolved in 100g of benzene and reacted at 180 ℃ under reflux for 4 hours. Vacuum filtering after reaction to obtain 3,3' -dodecaamino-di- (N- (4-naphthylamino) phenyl) propionamide. Obtained by the above methodThe yield of the amine antioxidant reaches 89.4 percent, the product purity reaches 98.4 percent, and the melting point of the antioxidant is 108.4 ℃. Process for preparing 3,3' -dodecaamino-di- (N- (4-naphthylamino) phenyl) propanamide¹³Analysis of C NMR (FIG. 1) was: 13.07, 22.35, 29.17 and 53.65 are-CH in the dodecylamine chain₂-absorption peak of carbon atom on amide bond, 34.27 for carbon atom attached to amide bond, 171.88 for amide bond; the carbon atoms on the benzene ring show three absorption peaks at 119.35, 122.49 and 140.06, while the carbon atoms on the naphthalene ring show a plurality of characteristic peaks at chemical shifts 125.88-127.25. The analysis of the mass spectrum (fig. 2) was: at 762.5 is the segregant peak for the amine antioxidant. FT-IR (FIG. 3) analysis was: 3340cm^-1Stretching vibration of a tertiary amine (2950 cm)^-1Stretching vibration of the methylene group at 2922cm^-1Stretching vibration of the joint with a methyl group, 1812cm^-1The position is a characteristic absorption peak generated by 1, 4 position substitution of a benzene ring, 1652cm^-1Characteristic absorption peak of amido bond. 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 compound of formula IV can be synthesized by the method of the present invention.

In the polyethylene granulation section, based on the mass of polyethylene, 0.1% of the amine antioxidant, 0.1% of bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, and 0.05% of calcium stearate are added, and the mixture is melt-extruded by an extruder, drawn into a wire, and granulated. 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

(1) Synthesis of dimethyl-3, 3' - (dodecylamino) dipropionate: 9.25g of dodecylamine is accurately weighed and dissolved in 78.3g of methanol, 21g of methyl acrylate is slowly dripped under stirring at the temperature of 25 ℃, and the reaction is carried out for 24 hours at the constant temperature of 25 ℃. After the reaction, unreacted methyl acrylate and solvent methanol are distilled out by reduced pressure distillation, and dimethyl 3,3' - (dodecylamino) dipropionate is obtained.

(2) Synthesis of 3,3' - (dodecaamino) dipropionyl chloride: accurately weighing 3.29g of dimethyl-3, 3' - (dodecylamino) dipropionate and dissolving in 30.6gIn chloroform, 25 ℃ and N₂Under the condition, 10ml of thionyl chloride is added dropwise in batches, and after the dropwise addition is finished, the reaction is heated to 40 ℃ and is carried out for 1 hour at constant temperature. After the reaction, thionyl chloride and chloroform are removed by reduced pressure distillation, and 3,3' - (dodecyl) dipropyl chloride is obtained.

(3)3,3' - (dodecylamino) -bis- (N- (4-aminophenyl) propionamide): accurately weighing 3.24g of p-phenylenediamine and dissolving the p-phenylenediamine in 16g of benzene at the temperature of 0 ℃ and N₂Slowly dripping 3.7g of 3,3' - (dodecaamino) dipropyl chloride under the condition, heating the reaction system to 25 ℃ after complete dripping, and reacting for 24 hours at constant temperature. And (3) carrying out vacuum filtration on the mixture after reaction to obtain the 3,3' - (dodecaamino) -bis- (N- (4-aminophenyl) propionamide).

(4) Synthesis of 3,3' -dodecaamino-bis- (N- (4-naphthylamino) phenyl) propionamide: accurately weighed were 4.32g of beta-naphthol, 5.09g of 3,3' - (dodecamino) -bis- (N- (4-aminophenyl) propionamide) and 0.5g I₂Dissolved in 100g of benzene and reacted at 120 ℃ under reflux for 4 hours. Vacuum filtering after reaction to obtain 3,3' -dodecaamino-di- (N- (4-naphthylamino) phenyl) propionamide.

The yield of the amine antioxidant obtained by the method reaches 91.6 percent, the product purity reaches 98.0 percent, and the melting point of the antioxidant is 108.1 ℃.

In the polyethylene granulation section, based on the mass of the polyethylene, 0.1% of the amine antioxidant, 0.1% of tris (2, 4-di-tert-butylphenyl) phosphite and 0.05% of zinc stearate are 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 3

(1) Synthesis of dimethyl-3, 3' - (dodecylamino) dipropionate: 9.25g of dodecylamine is accurately weighed and dissolved in 78.3g of methanol, 21g of methyl acrylate is slowly dripped under stirring at the temperature of 25 ℃, and the reaction is carried out for 24 hours at the constant temperature of 40 ℃. After the reaction, the unreacted methyl acrylate and the solvent methanol are distilled out by reduced pressure distillation, and the dimethyl-3, 3' - (dodecylamino) dipropionate is obtained.

(2) Synthesis of 3,3' - (dodecaamino) dipropionyl chloride: accurately weighing dimethyl 3,3' - (dodecylamine)Yl) dipropionate 3.29g was dissolved in chloroform 30.6g at 25 ℃ and N₂Under the condition, 6ml of thionyl chloride is added dropwise in batches, and the reaction is carried out for 3 hours at the constant temperature of 25 ℃. After the reaction, thionyl chloride and chloroform are removed by reduced pressure distillation, and 3,3' - (dodecyl) dipropyl chloride is obtained.

(3)3,3' - (dodecylamino) -bis- (N- (4-aminophenyl) propionamide): accurately weighing 3.24g of p-phenylenediamine and dissolving the p-phenylenediamine in 20g of benzene at the temperature of 0 ℃ and N₂Slowly dripping 5g of 3,3' - (dodecaamino) dipropyl chloride under the condition, heating the reaction system to 25 ℃ after complete dripping, and reacting for 24 hours at constant temperature. And (3) carrying out vacuum filtration on the mixture after reaction to obtain the 3,3' - (dodecaamino) -bis- (N- (4-aminophenyl) propionamide).

(4) Synthesis of 3,3' -dodecaamino-bis- (N- (4-naphthylamino) phenyl) propionamide: accurately weighed were 4.32g of beta-naphthol, 5.09g of 3,3' - (dodecamino) -bis- (N- (4-aminophenyl) propionamide) and 0.3g I₂Dissolved in 100g of benzene and reacted at 150 ℃ under reflux for 4 hours. Vacuum filtering after reaction to obtain 3,3' -dodecaamino-di- (N- (4-naphthylamino) phenyl) propionamide.

The yield of the amine antioxidant obtained by the method reaches 90.2 percent, the product purity reaches 98.2 percent, and the melting point of the antioxidant is 108.3 ℃.

In the granulating section of polyethylene, based on the mass of polyethylene, 0.1% of the amine antioxidant, 0.1 wt% of dilauryl thiodipropionate and 0.05% of zinc stearate are added, and the mixture is subjected to melt extrusion, wire drawing and granulation 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 4

(1) Synthesis of dimethyl-3, 3' - (dodecylamino) dipropionate: 9.25g of dodecylamine is accurately weighed and dissolved in 50g of methanol, 32g of methyl acrylate is slowly dripped under stirring at the temperature of 25 ℃, and the reaction is carried out for 18 hours at the constant temperature of 30 ℃. After the reaction, the unreacted methyl acrylate and the solvent methanol are distilled out by reduced pressure distillation, and the dimethyl-3, 3' - (dodecylamino) dipropionate is obtained.

(2) Synthesis of 3,3' - (dodecaamino) dipropionyl chloride: accurately weighing dimethyl 3,3' - (dodecylamino) dipropyl3.29g of the acid ester was dissolved in 20.5g of chloroform at 25 ℃ N₂4ml of thionyl chloride is added dropwise under the condition, and the reaction is carried out for 2 hours at the constant temperature of 40 ℃. After the reaction, thionyl chloride and chloroform are removed by reduced pressure distillation, and 3,3' - (dodecyl) dipropyl chloride is obtained.

(3)3,3' - (dodecylamino) -bis- (N- (4-aminophenyl) propionamide): accurately weighing 3.24g of p-phenylenediamine and dissolving the p-phenylenediamine in 30g of benzene at the temperature of 0 ℃ and N₂Slowly dripping 5g of 3,3' - (dodecaamino) dipropyl chloride under the condition, heating the reaction system to 25 ℃ after complete dripping, and reacting for 18 hours at constant temperature. And (3) carrying out vacuum filtration on the mixture after reaction to obtain the 3,3' - (dodecaamino) -bis- (N- (4-aminophenyl) propionamide).

(4) Synthesis of 3,3' -dodecaamino-bis- (N- (4-naphthylamino) phenyl) propionamide: 4.32g of beta-naphthol, 5.09g of 3,3' - (dodecylamino) -bis- (N- (4-aminophenyl) propionamide) and 0.3g I2 were dissolved in 100g of benzene and reacted at 150 ℃ under reflux for 4 hours. Vacuum filtering after reaction to obtain 3,3' -dodecaamino-di- (N- (4-naphthylamino) phenyl) propionamide.

The yield of the amine antioxidant obtained by the method reaches 87.8 percent, the product purity reaches 98.1 percent, and the melting point of the antioxidant is 108.1 ℃.

In the polyethylene granulation section, based on the mass of polyethylene, 0.05% of the amine antioxidant, 0.05% of bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, and 0.025% of calcium stearate are added, and the mixture is melt-extruded by an extruder, drawn into a wire, and granulated. 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 5

(1) Synthesis of dimethyl-3, 3' - (dodecylamino) dipropionate: 9.25g of dodecylamine is accurately weighed and dissolved in 78.3g of methanol, 43g of methyl acrylate is slowly dripped under stirring at the temperature of 25 ℃, and the reaction is carried out for 14 hours at the constant temperature of 30 ℃. After the reaction, the unreacted methyl acrylate and the solvent methanol are distilled out by reduced pressure distillation, and the dimethyl-3, 3' - (dodecylamino) dipropionate is obtained.

(2) Synthesis of 3,3' - (dodecaamino) dipropionyl chloride: accurately weighing dimethyl-3, 3' - (dodecylamine)) 3.29g of dipropionate dissolved in 30.6g of chloroform at 25 ℃ and N₂Under the condition, 8ml of thionyl chloride is added dropwise in batches, and the reaction is carried out for 6 hours at the constant temperature of 25 ℃. After the reaction, thionyl chloride and chloroform are removed by reduced pressure distillation, and 3,3' - (dodecyl) dipropyl chloride is obtained.

(3)3,3' - (dodecylamino) -bis- (N- (4-aminophenyl) propionamide): accurately weighing 3.24g of p-phenylenediamine and dissolving the p-phenylenediamine in 20g of benzene at the temperature of 0 ℃ and N₂Slowly dripping 5g of 3,3' - (dodecaamino) dipropyl chloride under the condition, heating the reaction system to 25 ℃ after complete dripping, and reacting for 24 hours at constant temperature. And (3) carrying out vacuum filtration on the solution after reaction to obtain the 3,3' - (dodecaamino) -bis- (N- (4-aminophenyl) propionamide).

(4) Synthesis of 3,3' -dodecaamino-bis- (N- (4-naphthylamino) phenyl) propionamide: accurately weighed were 4.32g of beta-naphthol, 5.09g of 3,3' - (dodecamino) -bis- (N- (4-aminophenyl) propionamide) and 0.3g I₂Dissolved in 50g of benzene and reacted at 180 ℃ under reflux for 4 hours. Vacuum filtering after reaction to obtain 3,3' -dodecaamino-di- (N- (4-naphthylamino) phenyl) propionamide.

The yield of the amine antioxidant obtained by the method reaches 90.7 percent, the product purity reaches 98.0 percent, and the melting point of the antioxidant is 108.2 ℃.

In the polyethylene granulation section, based on the mass of the polyethylene, 0.15% of the amine antioxidant, 0.15% of bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, and 0.075% of calcium stearate are added, and the mixture is subjected to melt extrusion, wire drawing and granulation 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

(1) Synthesis of dimethyl-3, 3' - (n-octylamino) dipropionate: accurately weighing 7.54g of n-octylamine, dissolving in 56.5g of methanol, slowly dropwise adding 43g of methyl acrylate at 25 ℃ while stirring, and reacting at 30 ℃ for 8 hours. After the reaction, the unreacted methyl acrylate and the solvent methanol are distilled out by reduced pressure distillation, and the dimethyl-3, 3' - (n-amino) dipropionate is obtained.

(2)3,3' - (n-octylamino) dipropyl chloride synthesis: accurately weighing dimethyl-3, 3' - (n-octylamino) di2.95g of propionate was dissolved in 28.4g of chloroform at 25 ℃ under N₂Under the condition, 8ml of thionyl chloride is added dropwise in batches, and the reaction is carried out for 6 hours at the constant temperature of 25 ℃. After the reaction, thionyl chloride and chloroform are removed by reduced pressure distillation, and 3,3' - (n-octylamino) dipropionyl chloride is obtained.

(3)3,3' - (N-octylamino) -bis- (N- (4-aminophenyl) propionamide): accurately weighing 3.24g of p-phenylenediamine and dissolving the p-phenylenediamine in 20g of benzene at the temperature of 0 ℃ and N₂Slowly dripping 3.0g of 3,3' - (n-octylamino) dipropyl chloride under the condition, heating the reaction system to 25 ℃ after complete dripping, and reacting for 24 hours at constant temperature. And (3) carrying out vacuum filtration on the reacted cyclic compound to obtain the 3,3' - (N-octylamino) -bis- (N- (4-aminophenyl) propionamide).

(4) Synthesis of 33,3' -N-octylamino-bis- (N- (4-naphthylamino) phenyl) propionamide: accurately weighed were 4.32g of beta-naphthol, 4.5g of 3,3' - (N-octylamino) -di- (N- (4-aminophenyl) propionamide) and 0.3g I₂Dissolved in 40g of benzene and reacted at 180 ℃ under reflux for 4 hours. After reaction, the 3,3' -N-octylamino-di- (N- (4-naphthylamino) phenyl) propionamide is obtained by vacuum filtration.

The yield of the amine antioxidant obtained by the method reaches 92.7 percent, the product purity reaches 98.7 percent, and the melting point of the antioxidant is 107.0 ℃.

In the polyethylene granulation section, based on the mass of polyethylene, 0.1% of the amine antioxidant, 0.1% of bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, and 0.05% of calcium stearate are added, and the mixture is melt-extruded by an extruder, drawn into a wire, and granulated. 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 7

(1) Synthesis of dimethyl-3, 3' - (n-decylamino) dipropionate: accurately weighing 8.5g of n-decylamine, dissolving the n-decylamine in 60g of methanol, slowly dropwise adding 43g of methyl acrylate under stirring at the temperature of 25 ℃, and reacting for 5 hours at the constant temperature of 40 ℃. After the reaction, unreacted methyl acrylate and solvent methanol are distilled out by reduced pressure distillation, and dimethyl-3, 3' - (n-decylamino) dipropionate is obtained.

(2)3,3' - (N-decylamino) dipropyl chloride synthesis: accurately weighing dimethyl-3, 3' - (n-decylamino) dipropyl3.2g of the acid ester was dissolved in 30g of chloroform at 25 ℃ N₂Under the condition, 6ml of thionyl chloride is added dropwise in batches, and the reaction is carried out for 4 hours at the constant temperature of 30 ℃. After the reaction, thionyl chloride and chloroform are removed by reduced pressure distillation, and 3,3' - (n-decylamino) dipropionyl chloride is obtained.

(3)3,3' - (N-decylamino) -bis- (N- (4-aminophenyl) propionamide): accurately weighing 3.24g of p-phenylenediamine and dissolving the p-phenylenediamine in 20g of benzene at the temperature of 0 ℃ and N₂Slowly dripping 4.5g of 3,3' - (n-decylamino) dipropyl chloride under the condition, heating the reaction system to 40 ℃ after complete dripping, and reacting for 14 hours at constant temperature. And (3) carrying out vacuum filtration on the mixture after reaction to obtain 3,3' - (N-decylamino) -bis- (N- (4-aminophenyl) propionamide).

(4) Synthesis of 3,3' -N-decylamino-bis- (N- (4-naphthylamino) phenyl) propionamide: accurately weighed were 4.32g of beta-naphthol, 4.7g of 3,3' - (N-decylamino) -di- (N- (4-aminophenyl) propionamide) and 0.3g I₂Dissolved in 45g of benzene and reacted at 140 ℃ under reflux for 6 hours. After reaction, the 3,3' -N-decylamine-di- (N- (4-naphthylamine) phenyl) propionamide is obtained by vacuum filtration.

The yield of the amine antioxidant obtained by the method reaches 90.5 percent, the product purity reaches 98.4 percent, and the melting point of the antioxidant is 107.6 ℃.

In the polyethylene granulation section, based on the mass of polyethylene, 0.1% of the amine antioxidant, 0.1% of bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, and 0.05% of calcium stearate are added, and the mixture is melt-extruded by an extruder, drawn into a wire, and granulated. 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 8

(1) Synthesis of dimethyl-3, 3' - (tetradecylamino) dipropionate: 10g of tetradecylamine is accurately weighed and dissolved in 80g of methanol, 40g of methyl acrylate is slowly dripped under stirring at the temperature of 25 ℃, and the reaction is carried out for 6 hours at the constant temperature of 80 ℃. After the reaction, unreacted methyl acrylate and solvent methanol are distilled out by reduced pressure distillation, and dimethyl-3, 3' - (tetradecylamino) dipropionate is obtained.

(2) Synthesis of 3,3' - (tetradecylamino) dipropionyl chloride: accurately weighing dimethyl-3, 3' - (tetradecylamino) dipropionate3.7g of the extract was dissolved in 35g of chloroform at 25 ℃ under N₂Under the condition, 10ml of thionyl chloride is added dropwise in batches, and the reaction is carried out for 6 hours at the constant temperature of 40 ℃. After the reaction, thionyl chloride and chloroform were removed by distillation under reduced pressure to obtain 3,3' - (tetradecylamino) dipropionyl chloride.

(3)3,3' - (tetradecylamino) -bis- (N- (4-aminophenyl) propionamide): accurately weighing 3.6g of p-phenylenediamine and dissolving the p-phenylenediamine in 20g of benzene at the temperature of 0 ℃ and N₂Slowly dripping 5.2g of 3,3' - (tetradecylamino) dipropyl chloride under the condition, heating the reaction system to 60 ℃ after completely dripping, and reacting for 20 hours at constant temperature. And (3, 3' - (tetradecylamino) -bis- (N- (4-aminophenyl) propionamide) is obtained by vacuum filtration of the mixture after reaction.

(4) Synthesis of 3,3' -tetradecylamino-bis- (N- (4-naphthylamino) phenyl) propionamide: accurately weighed were 5.3g of beta-naphthol, 6.4g of 3,3' - (tetradecylamino) -bis- (N- (4-aminophenyl) propionamide) and 0.5g I₂Dissolved in 60g of benzene and reacted at 180 ℃ under reflux for 10 hours. Vacuum filtering after reaction to obtain 3,3' -tetradecylamino-di- (N- (4-naphthylamino) phenyl) propionamide.

The yield of the amine antioxidant obtained by the method reaches 87.8 percent, the product purity reaches 98.1 percent, and the melting point of the antioxidant is 108.9 ℃.

In the polyethylene granulation section, based on the mass of polyethylene, 0.1% of the amine antioxidant, 0.1% of bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, and 0.05% of calcium stearate are added, and the mixture is melt-extruded by an extruder, drawn into a wire, and granulated. 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

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.