阅读说明：本技术 一种低酸型柴油抗磨剂及其制备方法和应用 (Low-acid diesel antiwear agent and preparation method and application thereof ) 是由 夏鑫 李宝石 李妍 蔺建民 于 2019-11-11 设计创作，主要内容包括：本发明涉及一种低酸型柴油抗磨剂及其制备方法,所述柴油抗磨剂含有烯基琥珀酸双酯。本发明所述低硫柴油抗磨剂是由以下方法制备的：由含有C8～C24不饱和脂肪酸或含有C8～C24不饱和脂肪酸烷基酯的原料与C4～C6不饱和二羧基酸酐和/或不饱和二羧酸进行加成反应,得到烯基琥珀酸酐和/或烯基琥珀酸反应中间体；所述烯基琥珀酸酐和/或烯基琥珀酸与脂肪醇按照1:2.6～10的摩尔比进行酯化反应,得到烯基琥珀酸双酯。本发明所制备的抗磨剂添加量小,能够显著提高低硫柴油的润滑性,对柴油的酸度影响小。(The invention relates to a low-acid diesel antiwear agent and a preparation method thereof. The low-sulfur diesel antiwear agent is prepared by the following method: carrying out addition reaction on a raw material containing C8-C24 unsaturated fatty acid or C8-C24 unsaturated fatty acid alkyl ester and C4-C6 unsaturated dicarboxylic anhydride and/or unsaturated dicarboxylic acid to obtain alkenyl succinic anhydride and/or an alkenyl succinic acid reaction intermediate; and carrying out esterification reaction on the alkenyl succinic anhydride and/or the alkenyl succinic acid and fatty alcohol according to the molar ratio of 1: 2.6-10 to obtain alkenyl succinic diester. The antiwear agent prepared by the invention has small addition amount, can obviously improve the lubricity of low-sulfur diesel oil, and has small influence on the acidity of the diesel oil.)

1. A diesel antiwear agent comprising an alkenyl succinic diester represented by the following structural formula 1:

wherein R is₁、R₂Is a hydrocarbon radical with or without double bonds, R₁And R₂The total carbon number of (2) is 8-24, the total double bond number is 0, 1 or 2, R₃Is hydrogen or C₁-C₄A hydrocarbon group of R₄Is C₁-C₃A hydrocarbon group of R₅Is C₁-C₈A hydrocarbon group of (1).

2. The antiwear agent of claim 1, wherein R₁、R₂12 to 22, more preferably 16 to 20, R₃Is hydrogen or methyl or ethyl; r₄Is methylene; r₅Is C₁～C₅Alkyl group of (1).

3. A preparation method of a diesel antiwear agent comprises the following steps:

(1) from a composition containing C₈～C₂₄Unsaturated fatty acids or containing C₈～C₂₄Starting materials for unsaturated fatty acid alkyl esters and C₄～C₆Carrying out addition reaction on unsaturated dicarboxylic anhydride and/or unsaturated dicarboxylic acid to obtain alkenyl succinic anhydride and/or alkenyl succinic acid reaction intermediate;

(2) and carrying out esterification reaction on the alkenyl succinic anhydride and/or the alkenyl succinic acid and fatty alcohol according to the molar ratio of 1: 2.6-10 to obtain alkenyl succinic diester.

4. The preparation method according to claim 3, wherein, in the step (1), the reaction temperature is 100-280 ℃, preferably 180-240 ℃.

5. The method according to claim 3, wherein the C-containing compound is₈～C₂₄Unsaturated fatty acids or containing C₈～C₂₄In the unsaturated fatty acid alkyl ester raw material, the unsaturated fatty acid is C₈～C₂₄Long chain alkenoic acids containing one, two or three double bonds, wherein the alkyl ester is C₁～C₄An alkyl ester.

6. The production method according to claim 3, wherein the unsaturated fatty acid is preferably C₁₂～C₂₂Unsaturated fatty acids, more preferably C₁₆～C₂₀Unsaturated fatty acids; and/or, the unsaturated fatty acid alkyl ester is preferably C₁₂～C₂₂Unsaturated fatty acid methyl and ethyl esters, more preferably C₁₆～C₂₀Unsaturated fatty acid methyl ester.

7. The method of claim 3, wherein the unsaturated fatty acid is selected from the group consisting of oleic acid, linoleic acid, and erucic acid, and mixtures thereof; and/or the unsaturated fatty acid alkyl ester is selected from methyl oleate, methyl linoleate and methyl erucate and a mixture thereof.

8. The method according to claim 3, wherein said C is₄～C₆The unsaturated dicarboxylic anhydride is selected from maleic anhydride, itaconic anhydride, citraconic anhydride, and ethylmaleic anhydride.

9. The production process according to claim 3, wherein in the step (1), the molar ratio of the unsaturated fatty acid or unsaturated fatty acid alkyl ester to the unsaturated dicarboxylic anhydride and/or unsaturated dicarboxylic acid is 1:0.5 to 3, preferably 1:1 to 2.

10. The production process according to claim 3, wherein, in the step (2), the esterification reaction temperature is 40 to 180 ℃, preferably 50 to 120 ℃.

11. The preparation method according to claim 3, wherein an antioxidant is further added in step (1) or/and step (2).

12. The method according to claim 3, wherein the fatty alcohol is selected from C₁-C₈Monohydric alcohols, preferably C₁-C₅Monohydric alcohol, more preferably C₁-C₂A monohydric alcohol of (1).

13. The production method according to claim 3, wherein the molar ratio of the alkenylsuccinic anhydride and/or alkenylsuccinic acid to the fatty alcohol is 1:3 to 8.

14. A diesel antiwear agent prepared by the method of any one of claims 3 to 13.

15. A diesel oil composition comprising a low sulfur diesel oil and the diesel oil antiwear agent of claim 1, 2 or 14, wherein the diesel oil antiwear agent is added to the low sulfur diesel oil in an amount of 50 to 500 mg-kg^-1Preferably 100-300 mg-kg^-1。

Technical Field

The present invention belongs to a diesel oil additive, particularly to a diesel oil antiwear agent, which is an additive for improving the lubricity of low-sulfur diesel oil.

Background

Along with environmental protectionIncreasingly strict legal requirements are met, and low vulcanization of diesel oil is a necessary trend. The sulfur content of diesel oil specified by national standards V and VI of diesel oil is 10 mg/kg^-1And the desulfurized diesel oil is implemented in domestic refineries, and sulfur reduction technologies such as hydrotreating and hydrocracking are adopted in China at present.

The strength of the lubricity of the diesel oil depends on the content of an anti-wear substance, the polycyclic aromatic hydrocarbon and the nitrogen-containing compound have good anti-wear effect, sulfide does not resist wear but promotes wear, but sulfide in the diesel oil mostly exists in aromatic hydrocarbon and polycyclic aromatic hydrocarbon in a heterocyclic ring form, and aromatic hydrocarbon and polycyclic aromatic hydrocarbon with lubricating property and other components with lubricating property are removed while the sulfide is greatly promoted to be removed due to serious environmental pollution. In order to avoid the abrasion and damage of the diesel engine along with the reduction of the sulfur content in the diesel, the antiwear agent is added into the low-sulfur diesel in the simplest and most widely adopted method for improving the lubricating property of the low-sulfur diesel at present. The method using the additive has the advantages of low cost, flexible production, low pollution and the like, and is widely regarded in industry.

The existing low-sulfur diesel oil antiwear agent mainly comprises an acid type antiwear agent and an ester type antiwear agent, wherein the acid type antiwear agent mainly comprises long-chain fatty acids such as oleic acid, linoleic acid, linolenic acid and the like, and a typical product is refined tall oil fatty acid. The ester-type antiwear agent is an esterification reaction product of the above fatty acid with a polyhydric alcohol. With the upgrading of diesel oil standards and the improvement of quality requirements, the limitation on the content of impurities and harmful substances in the acid type antiwear agent and the ester type antiwear agent is more and more strict. China petrochemical group company executes the purchasing and admittance and inspection standards of diesel anti-wear agents from 2007, and currently executes Q/SHCG 57-2017, and the purchasing standards are approved by other diesel manufacturers in China and are executed by reference in the use of anti-wear agents. The acid value of the standard antiwear agent is strictly required, wherein the acid value range of the acid type antiwear agent is 185-210 mgKOH/g; the ester type antiwear agent requires an acid value of not more than 1 mgKOH/g.

The fatty acid antiwear agents currently disclosed, such as patent US2008098642 disclose 50-95% C₁₂-C₂₄The fatty acid and the ester derivative compound prepared by taking the nutshell liquid as the raw material are used as the diesel antiwear agent. Although the antiwear effect is better, the acid value is higher. The acid additive and the high-base number dispersant have neutralization reaction to destroy the center of colloid and generate calcium salt or magnesium salt of carboxylic acid, thereby causing the problem of fuel filter screen blockage. In addition, the fatty acid type antiwear agent is used for solving the problems of diesel oil lubricity, namely the cost is relatively low, but the problems of excessive diesel oil acidity, increased corrosivity risk and the like are caused by large dosage along with the upgrading of diesel oil emission standards and the deterioration of lubricity. Patent CN108219874A discloses a formula of a compound antiwear agent for ultra-low sulfur diesel, tall oil fatty acid and hydroxyquinoline nitrogen-containing compounds are compounded, the compound antiwear agent can greatly reduce the addition amount of the tall oil fatty acid antiwear agent and improve the lubricating property of the diesel, but the tall oil fatty acid is easy to chemically react with metal.

At present, most of the fatty acid ester type low-sulfur diesel antiwear agents researched are fatty acid polyol esters, which have good antiwear performance and good compatibility with other diesel additives such as low-temperature flow improvers or amide ashless dispersants. There are many patents published at home and abroad relating to, for example, patent EP 0739970 which discloses a mixture of glycerides as a low sulfur diesel antiwear agent, the mixture comprising glycerides having different degrees of esterification. Patent US6511520 discloses a low sulfur diesel antiwear agent, the main components of which are fatty acid monoglyceride and fatty acid diglyceride. Patent CN 101787318A discloses a low-sulfur diesel antiwear agent prepared by mixing fatty acid monoglyceride and fatty acid diglyceride and compounding the mixture with dimer acid. However, the fatty acid polyol ester is generally synthesized by partially esterifying an unsaturated fatty acid and a polyol, or by partially transesterifying an animal or vegetable fat and a polyol. In the synthesis process, a large amount of inorganic acid and alkali such as sulfuric acid and caustic soda are needed to be used as catalysts, which have strong corrosion to equipment, and a large amount of wastewater is generated in the production process.

Disclosure of Invention

The invention provides a low-acid diesel antiwear agent based on the prior art.

The invention also provides a preparation method of the diesel antiwear agent.

The invention also provides a diesel oil composition containing the antiwear agent.

In a first aspect, the diesel antiwear agent of the present invention comprises an alkenyl succinic diester represented by structural formula 1:

wherein R is₁、R₂Is a hydrocarbon radical with or without double bonds, R₁And R₂Has a total carbon number of 8 to 24, preferably 12 to 22, more preferably 16 to 20, and a total degree of unsaturation (total number of double bonds) of 0, 1 or 2, for example R₁And R₂May be alkyl, alkenyl, dienyl, and the like; r₃Is hydrogen or C₁-C₄Preferably hydrogen or methyl or ethyl; r₄Is C₁-C₄Preferably a methylene group; r₅Is C₁-C₈Is preferably C₁～C₅Among them, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl and the like are preferable, and methyl and ethyl are preferable.

In a second aspect, the invention provides a preparation method of a low-acid diesel antiwear agent, which comprises the following steps:

(1) from a composition containing C₈～C₂₄Unsaturated fatty acids or containing C₈～C₂₄Starting materials for unsaturated fatty acid alkyl esters and C₄～C₆Carrying out addition reaction on unsaturated dicarboxylic anhydride and/or unsaturated dicarboxylic acid to obtain alkenyl succinic anhydride and/or alkenyl succinic acid reaction intermediate;

(2) and carrying out esterification reaction on the alkenyl succinic anhydride and/or the alkenyl succinic acid and fatty alcohol according to the molar ratio of 1: 2.6-10 to obtain alkenyl succinic diester.

In the step (1), the reaction can be carried out at the reaction temperature of 100-280 ℃, preferably at the reaction temperature of 180-240 ℃. The reaction time is generally 1 to 20 hours, preferably 6 to 12 hours. The reaction may be catalyzed by acids such as sulfuric acid, p-toluenesulfonic acid, aluminum chloride, and the like, and may be carried out without a catalyst, preferably without a catalyst.

Said compound containing C₈～C₂₄Unsaturated fatty acids or containing C₈～C₂₄In the unsaturated fatty acid alkyl ester raw material, the unsaturated fatty acid can be C₈～C₂₄Long chain alkenoic acids containing one, two or three double bonds, wherein the alkyl ester may be C₁～C₄An alkyl ester. The unsaturated fatty acid is preferably C₁₂～C₂₂More preferably C₁₆～C₂₀Unsaturated fatty acids, e.g. palmitoleic acid (C)₁₆Olefine acid, oleic acid (C)₁₈Olefine acid, linoleic acid (C)₁₈Dienoic acid), linolenic acid (C)₁₈Trienoic acid), arachidonic acid (C)₂₀Olefine acid, erucic acid (C)₂₂Olefinic acid), etc., and the most preferable examples are oleic acid, linoleic acid and erucic acid, and mixtures thereof; the unsaturated fatty acid alkyl ester is preferably C₁₂～C₂₂Unsaturated fatty acid methyl and ethyl esters, more preferably C₁₆～C₂₀Unsaturated fatty acid methyl esters, e.g. palmitoleic acid (C)₁₆Olefine acid) methyl ester, oleic acid (C)₁₈Olefine acid) methyl ester, linoleic acid (C)₁₈Dienoic acid) methyl ester, linolenic acid (C)₁₈Trienoic acid) methyl ester, arachidic acid (C)₂₀Olefine acid) methyl ester, erucic acid methyl ester (C)₂₂Olefinic acid), etc., and the most preferred examples are methyl oleate, methyl linoleate, and methyl erucate, and mixtures thereof.

Said C is₄～C₆The unsaturated dicarboxylic anhydride being C₄～C₆The anhydride of the unsaturated dicarboxylic acid may be selected from maleic anhydride, itaconic anhydride (2-methylenesuccinic anhydride), citraconic anhydride (methyl maleic anhydride), and ethyl maleic anhydride, with maleic anhydride being preferred.

The above unsaturated fatty acids and unsaturated fatty acid alkyl esters are referred to simply as unsaturated fatty acids (esters), above C₄～C₆Unsaturated dicarboxylic anhydrides and C₄～C₆Unsaturated diCarboxylic acids are referred to as unsaturated acids (anhydrides).

The molar ratio of unsaturated fatty acid (ester) to unsaturated acid (anhydride) may vary from about 1:0.5 to 3, e.g., 1:1.3, and the unsaturated acid (anhydride) may be used in excess to drive the reaction to completion. The unreacted unsaturated acid (anhydride) can be removed by vacuum distillation such as vacuum distillation and molecular distillation.

In step (2), the esterification reaction can be carried out at a temperature of 40 to 180 ℃, preferably 50 to 120 ℃. The reaction time is generally 10 minutes to 8 hours, preferably 1 hour to 5 hours. The reaction can be carried out by using an acid catalyst, such as one or more of aluminum chloride, sulfuric acid, hydrochloric acid, boron trifluoride, solid super acid, cation exchange resin, heteropoly acid and the like; it is also possible to use no catalyst, which can accelerate the reaction rate but can initiate side reactions, and it is therefore preferred not to use a catalyst.

The fatty alcohol is selected from C₁-C₈Monohydric alcohols, preferably C₁-C₅Monohydric alcohols, such as methanol, ethanol, propanol, butanol, pentanol, and the like, most preferably C₁-C₂And monohydric alcohols such as methanol and ethanol. The molar ratio of the alkenyl succinic anhydride or the alkenyl succinic acid to the fatty alcohol may be 1:2.6 to 10, preferably 1:3 to 8.

According to the process of the present invention, in the step (1) and the step (2), a reaction solvent such as toluene, xylene, ethylbenzene or the like may be further added as required.

According to the process of the present invention, in step (1) or/and step (2), an antioxidant may be added. A series of free radical chain reactions can occur in the thermal oxidation process of reactants, and chemical bonds of the reactants are broken under the action of heat, light or oxygen to generate active free radicals and hydroperoxide. The hydroperoxide undergoes decomposition reactions, which also generate hydroxyl radicals and hydroxyl radicals. These radicals can initiate a series of radical chain reactions, leading to radical changes in the structure and properties of the reactants. The antioxidant functions to scavenge the free radicals that have just been generated or to promote the decomposition of the hydroperoxide, preventing the chain reaction from proceeding. The antioxidant can be a phenolic antioxidant, such as monophenol, diphenol, bisphenol or polyphenol, or a mixture thereof in any proportion, and specifically can be: one or more of 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) isooctyl acrylate, antioxidant 1010, antioxidant 2246, antioxidant 1076, antioxidant 300 and the like; can be amine type antioxidant, such as arylamine antioxidant, for example one or more of naphthylamine derivative, diphenylamine derivative, p-phenylenediamine derivative and quinoline derivative, and specifically can be: one or more of N ', N-diphenyl-p-phenylenediamine, N' -hexamethylene-bis-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionamide, phenothiazine (vulcanized diphenylamine), antioxidant DNP, antioxidant H, antioxidant 4010 and the like; heterocyclic antioxidants, such as benzotriazole, alkyl substituted imidazoline, 2-mercaptobenzothiazole, 2, 5-dimercapto-1, 3, 4-thiadiazole and derivatives thereof.

According to the method of the present invention, the amount of the antioxidant added may be 0.01% to 10%, preferably 0.5% to 5%, more preferably 0.5% to 1% of the total mass of the reactants.

In a third aspect, the invention provides a diesel oil composition, which comprises low-sulfur diesel oil and the diesel oil antiwear agent, wherein the sulfur content of the low-sulfur diesel oil is less than 500 mg-kg^-1The diesel antiwear agent provided by the invention is added into low-sulfur diesel oil in an amount of 50-500 mg/kg^-1Preferably 100-300 mg-kg^-1。

The additive provided by the invention can be used together with other additives such as flow improver, cetane number improver, detergent dispersant metal deactivator, preservative and the like according to the use requirement.

The preparation method of the diesel antiwear agent provided by the invention has the advantages of easily available raw materials, low cost, simple and convenient production, small addition amount and small influence on the acidity of diesel, and can obviously improve the lubricity of low-sulfur diesel when being used as the diesel antiwear agent.

Drawings

FIG. 1 is a mass spectrum of the antiwear agent product prepared in example 2, namely: is a methyl oleate-based succinic acid diester prepared from methyl oleate, maleic anhydride and methanol, wherein m/z is 463.25, which is the sodium ion mass spectrum addition peak of the methyl oleate-based succinic acid diester prepared in example 2.

FIG. 2 is an IR spectrum of the antiwear agent product of methyl oleate-bis (methyl succinate) prepared in example 2 at 2800cm^-1～3000cm^-1And 1450cm^-1Peaks indicate aliphatic hydrocarbon structure; 1737cm^-1The peak represents the ester group at the long chain end; 1206cm-¹The nearby peaks indicate the C-O structure.

Detailed Description

In the examples, methyl oleate (96% content) and ethyl oleate (96% content) were produced by Shanghai Aradine Biotechnology Co., Ltd., methyl erucate (90% content) was produced by Taixi (Shanghai) chemical development Co., Ltd., oleic acid (85% content) was produced by Taixi (Shanghai) chemical development Co., Ltd., anhydrous methanol (99.5% content), anhydrous ethanol (99.7% content) was produced by the national drug group chemical reagent Co., Ltd., maleic anhydride (99.5% content) was produced by Beijing Yinuoka technology Co., Ltd., n-propanol (99.7% content) and n-pentanol (98% content) were produced by Shanghai Aradine Biotechnology Co., Ltd.

The following examples further illustrate the invention.

Preparation examples 1 to 4 are provided to illustrate the synthesis of alkenyl succinic anhydride, which is a reaction intermediate.

Preparation example 1

Adding 1500g of methyl oleate (the mass fraction is 96%) and 745g of maleic anhydride (the molar ratio of methyl oleate to maleic anhydride is about 1:1.5) into a 3000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen introduction tube, introducing nitrogen for 5-10 minutes while maintaining the protection of nitrogen in the reaction process, heating and stirring to raise the temperature to 180 ℃, carrying out reflux reaction for 5 hours, and removing excessive maleic anhydride through reduced pressure distillation to obtain the reaction intermediate alkenyl succinic anhydride containing the example of the following structural formula 2 or structural formula 3.

Preparation example 2

1500g of methyl oleate (96% by weight) and 993.4g of maleic anhydride (the molar ratio of methyl oleate to maleic anhydride is about 1:2) were placed in a 3000ml reactor equipped with an electric stirrer, a thermometer, a reflux condenser and a nitrogen inlet, and about 12.5g of 2246 antioxidant (technical grade, Nanjing Ruiyi Yanhua) was added in an amount of about 0.5% by weight of the total mass of the reactants. And introducing nitrogen for 5-10 minutes, keeping the protection of the nitrogen in the reaction process, heating and stirring to raise the temperature to 230 ℃, carrying out reflux reaction for 8 hours, and removing excessive maleic anhydride through reduced pressure distillation to obtain a reaction intermediate alkenyl succinic anhydride.

Preparation example 3

Adding 310g of ethyl oleate (the mass fraction is 96%) and 295g of maleic anhydride (the molar ratio of ethyl oleate to maleic anhydride is about 1:3) into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen introduction tube, introducing nitrogen for 5-10 minutes, keeping nitrogen protection in the reaction process, heating and stirring to 200 ℃, carrying out reflux reaction for 8 hours, and removing excessive maleic anhydride through reduced pressure distillation to obtain a reaction intermediate alkenyl succinic anhydride.

Preparation example 4

Adding 500g of oleic acid (the mass fraction is 85%) and 260.4g of maleic anhydride (the molar ratio of the oleic acid to the maleic anhydride is about 1:1.5) into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen introduction tube, introducing nitrogen for 5-10 minutes, keeping the protection of the nitrogen in the reaction process, heating and stirring to 170 ℃, carrying out reflux reaction for 6 hours, and removing excessive maleic anhydride through reduced pressure distillation to obtain a reaction intermediate alkenyl succinic anhydride.

Examples 1-8 are provided to illustrate the synthesis of alkenyl succinic acid diester shown in formula 1. In these examples, the acid value of the antiwear agent product is determined by the method GB/T7304-.

Example 1:

cooling the product of preparation example 1 to 60 ℃, putting 500g of the product into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 103.8g of methanol (the molar ratio of alkenyl succinic anhydride to fatty alcohol is 1:2.5), introducing nitrogen for 5-10 minutes, stirring at constant temperature of 60 ℃, reacting for 1 hour, and cooling to obtain the product of the methyl oleate-dimethyl succinate. The acid value was 1.09 mgKOH/g.

Example 2:

cooling the product of preparation example 2 to 70 ℃, taking 500g of the product, placing the 500g of the product in a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 218g of methanol (the molar ratio of alkenyl succinic anhydride to fatty alcohol is 1:5), introducing nitrogen for 5-10 minutes, stirring at constant temperature of 70 ℃, reacting for 4 hours, and cooling to obtain the product of the methyl oleate bismethyl succinate containing the example of the structural formula 4 or the structural formula 5. The acid value was 0.82 mgKOH/g.

Example 3:

cooling the product of preparation example 3 to 100 ℃, taking 150g of the product, placing the 150g of the product into a 500ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 183g of n-propanol (the molar ratio of alkenyl succinic anhydride to fatty alcohol is 1:8), introducing nitrogen for 5-10 minutes, stirring at constant temperature of 100 ℃, reacting for 6 hours, and cooling to obtain the product of ethyl oleate-succinate di-n-propanol. The acid value was 0.71 mgKOH/g.

Example 4:

cooling the product of preparation example 2 to 90 ℃, taking 500g of the product, placing the 500g of the product into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 364g of methanol (the molar ratio of alkenyl succinic anhydride to fatty alcohol is 1:9), introducing nitrogen for 5-10 minutes, stirring at the constant temperature of 90 ℃, reacting for 2 hours, and cooling to obtain the product of the methyl oleate-dimethyl succinate. The acid value was 0.88 mgKOH/g.

Example 5:

cooling the product of preparation example 3 to 80 ℃, placing 150g of the product into a 250ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 52.8g of ethanol (the molar ratio of alkenyl succinic anhydride to fatty alcohol is 1:3), introducing nitrogen for 5-10 minutes, stirring at the constant temperature of 80 ℃, reacting for 1 hour, and standing for 24 hours to obtain the diethanol oleate succinate product. The acid value was 0.92 mgKOH/g.

Example 6:

cooling the product of the preparation example 2 to 70 ℃, putting 500g of the product into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 559g of n-amyl alcohol (the molar ratio of alkenyl succinic anhydride to fatty alcohol is 1:5), introducing nitrogen for 5-10 minutes, stirring at the constant temperature of 140 ℃, reacting for 2 hours, and cooling to obtain the bis-n-amyl oleate succinate product. The acid value was 0.83 mgKOH/g.

Example 7:

120g of methyl erucate (the mass fraction of which is 90 percent and is produced by TCI company in Japan) and 60.2g of maleic anhydride (the molar ratio of the methyl erucate to the maleic anhydride is about 1:2) are placed in a 250ml reactor which is provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen introducing tube, nitrogen is introduced for 5-10 minutes, the mixture is heated and stirred to 225 ℃, the reaction is carried out for 10 hours, and the excessive maleic anhydride is removed through reduced pressure distillation, so as to obtain the methyl erucate succinate anhydride reaction intermediate.

After the erucic acid methyl ester succinic anhydride reaction intermediate is cooled to 70 ℃, 100g of the erucic acid methyl ester succinic anhydride reaction intermediate is placed into a 250ml reactor which is provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, 38.8g of methanol (the molar ratio of alkenyl succinic anhydride to methanol is 1:3) is added, nitrogen is introduced for 5-10 minutes, the temperature is kept constant at 110 ℃ for stirring, methanol is removed after reflux reaction is carried out for 4 hours, and the product of the oleic acid methyl ester succinic acid monomethyl ester antiwear agent is obtained after cooling to room temperature.

Example 8:

cooling the product of preparation example 4 to 70 ℃, placing 500g of the product into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 110g of methanol (the molar ratio of alkenyl succinic anhydride to fatty alcohol is 1:2.5), introducing nitrogen for 5-10 minutes, stirring at constant temperature of 70 ℃, reacting for 3 hours, and cooling to obtain the oleic acid base succinic acid dimethyl succinate product. The acid value was 1.13 mgKOH/g.

Comparative example 1:

methyl oleate (96% by mass, Shanghai Allantin Biotechnology Co., Ltd.).

Comparative example 2:

oleic acid (85% by weight, produced by Taishiai chemical industry Co., Ltd., Shanghai) is added at 200 mg/kg^-1Adding into base diesel oil, and carrying out diesel oil abrasion test.

Comparative example 3:

afton 4140 (commercial diesel antiwear agent, Afton, USA).

Example 9 lubricity test

Lubricity of Diesel oil the scuffing Diameter (Wear Scar Diameter, WSD) at 60 ℃ was measured on a High-Frequency Reciprocating tester (HFRR) (manufactured by PCS instruments of the United kingdom) according to the method described in CEC-F-06-A-96 or ISO/FDIS 12156-1 (ASTM D6079), and the reported result WS1.4 was obtained by correcting the influence of temperature and humidity. The HFRR method (ISO 12156-1) trace diameter WS1.4 of the diesel before and after addition is shown in Table 2, wherein the smaller the trace diameter, the better the lubricity of the diesel. At present, most of diesel oil standards in the world, such as European standard EN 590 and China automotive diesel oil standard GB/T19147, use the trace grinding diameter less than 460 μm (60 ℃) as the basis of the qualified diesel oil lubricity standard.

The sulfur content of the low-sulfur diesel oil used in the lubricating property test is 6mg kg^-1、11mg·kg^-1Specific properties of diesel fuels having respective worn-spot diameters of 640 μm and 545 μm are shown in Table 1.

TABLE 1 physicochemical Properties of Diesel oil

The antiwear agent prepared by the invention is added into low-sulfur diesel oil for lubricating performance test, and the test result is shown in table 2.

TABLE 2 improvement of lubricity of diesel fuel by antiwear product

As can be seen from Table 2, the lubricating property of low-sulfur diesel oil can be greatly improved by adding a small amount of the product of the invention, so that the diesel oil antiwear agent provided by the invention can well improve the lubricating property of low-sulfur diesel oil. Particularly, the unexpected effect of the alkenyl succinic acid double methanol ester and the alkenyl succinic acid double ethanol ester product on improving the lubricating property of the diesel oil is most obvious and is far better than that of the alkenyl succinic acid double propylene ester or the alkenyl succinic acid double amyl alcohol ester.

Example 9 acidity test

The acidity of the diesel oil sample added with the diesel oil antiwear agent is tested according to the method specified in GB/T258-2016 (acidity determination for light Petroleum products), and the results are shown in Table 3.

TABLE 3 Effect of antiwear product on Diesel acidity

As can be seen from Table 3, the antiwear product prepared has little effect on the acidity of diesel.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.