阅读说明：本技术 一种柴油抗磨剂及其制备方法和应用 (Diesel antiwear agent and preparation method and application thereof ) 是由 夏鑫 蔺建民 李妍 李宝石 于 2019-11-11 设计创作，主要内容包括：本发明涉及一种低硫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单酯。本发明所述低硫柴油抗磨剂是由以下方法制备的：将不饱和脂肪酸或不饱和脂肪酸烷基酯与不饱和酸酐或不饱和二羧酸在100-280℃反应获得不饱和脂肪酸(酯)基琥珀酸(酐)中间体,再与脂肪醇在40-180℃按照1:0.5～1.2的摩尔比反应,得到烯基琥珀酸单酯。本发明所制备的抗磨剂的添加量低,能够显著提高低硫柴油的润滑性。(The invention relates to a low-sulfur diesel antiwear agent and a preparation method thereof. The low-sulfur diesel antiwear agent is prepared by the following method: unsaturated fatty acid or unsaturated fatty acid alkyl ester reacts with unsaturated acid anhydride or unsaturated dicarboxylic acid at the temperature of 100-280 ℃ to obtain an unsaturated fatty acid (ester) radical succinic acid (anhydride) intermediate, and then the unsaturated fatty acid (ester) radical succinic acid (anhydride) intermediate reacts with fatty alcohol at the temperature of 40-180 ℃ according to the molar ratio of 1: 0.5-1.2 to obtain alkenyl succinic acid monoester. The antiwear agent prepared by the invention has low addition amount, and can remarkably improve the lubricity of low-sulfur diesel.)

1. A diesel antiwear agent comprising an alkenyl succinic acid monoester represented by the 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～C₄Alkyl 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 a molar ratio of 1: 0.5-1.2 to obtain alkenyl succinic acid monoester.

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 1:0.8 to 1.1.

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

With the increasingly strict requirements of environmental protection laws, 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 followingThe 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.

At present, the domestic diesel oil lubricity improver mainly adopts fatty acid type, but the fatty acid type diesel oil lubricity improver has more problems in use, such as: when added into diesel oil, the fatty acid type diesel oil lubricity improver has compatibility problems with other additives of the diesel oil, in particular to a diesel oil detergent. The fatty acid reacts with the nitrogen-containing compounds within the diesel detergent, resulting in a dual reduction in antiwear and detergent properties. Patent US2009/0056203a1 discloses a branched carboxylic acid as a low sulfur diesel antiwear agent, the branched carboxylic acid employed comprising: isostearic acid, neodecanoic acid, isovaleric acid and the like, and the compound use effect of two or more branched chain carboxylic acids is better. However, the carboxylic acid type antiwear agent has a problem such as serious clogging of a fuel filter, and if the acidity of the antiwear agent is too strong, corrosion of metal may occur.

The fatty acid alkyl ester type antiwear agent well avoids the problems, belongs to a fatty acid type improved product, has better lubricating effect on diesel oil than the fatty acid type antiwear agent under the condition of the same dosage, does not react with other diesel oil additives, and is an optimal substitute product of the fatty acid type.

Patent EP 0605857 discloses that fatty acid alkyl ester such as rapeseed oil, sunflower oil, castor oil, etc. is directly used as diesel antiwear agent, and these products have the advantages of easily available raw materials, low price, etc., but the use effect is relatively poor, which brings inconvenience to practical application. Patent WO2002100987 uses fatty amine-fatty acid alkyl ester-fatty acid mixture as diesel antiwear agent, and the preparation process is that high melting point fatty acid and refined fusel oil are obtained first, then the high melting point fatty acid and unsaturated refined fusel oil are esterified to obtain ester, then the high melting point fatty acid and diamine compound or lactam, N-dimethylamine or N, N-diethylamine are reacted to obtain fatty acid amine, and finally the product is obtained, and the preparation process is complex. CN106929112A discloses a method for improving the abrasion resistance of low-sulfur diesel, which improves the lubricity of diesel by esterification reaction products of alkenyl succinic anhydride and monohydric aliphatic alcohol, but the product has high viscosity and general effect of improving the lubricity of ultra-low-sulfur diesel (such as vehicle diesel reaching the national VI emission standard), and meanwhile, the alkenyl in the alkenyl succinic anhydride is derived from oligomerization of ethylene, propylene or butylene, and the active ingredients in the product are low and do not belong to renewable resources.

Disclosure of Invention

The invention provides a low-sulfur diesel anti-wear agent with better lubricating property 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 acid monoester 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, methyl or ethyl; r₄Is C₁-C₃Preferably 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 C is more preferable₁～C₂Alkyl groups such as methyl, ethyl.

In a second aspect, the invention provides a preparation method of a 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 a molar ratio of 1: 0.5-1.2 to obtain alkenyl succinic acid monoester.

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 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)₁₈DieneAcid), 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. Said C is₄～C₆Unsaturated dicarboxylic acids are defined by the above-mentioned C₄～C₆The unsaturated anhydride is hydrolyzed to form the dicarboxylic acid.

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 simply as unsaturated acids (anhydrides).

The molar ratio of unsaturated fatty acid (ester) to unsaturated acid (anhydride) may be between about 1:0.5 and 3, preferably 1:1 to 2, e.g. 1:1.3, and the unsaturated acid (anhydride) may be used in excess to drive the reaction to completion.

The reaction of unsaturated fatty acids (esters) with unsaturated acids (anhydrides) is achieved by "ene reaction" (semi-Diels-Alder reaction). According to the reaction mechanism thereof, there are two possibilities of the position of the C ═ C double bond on the unsaturated fatty acid (ester) main chain in the unsaturated fatty acid (ester) group succinic anhydride (alkenyl succinic anhydride) intermediate structure obtained by the reaction. For example, starting from methyl oleate (18-enoic acid methyl ester) and maleic anhydride, the following reaction scheme exists:

starting from oleic acid (18-enoic acid) and maleic anhydride, the following reaction scheme exists:

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 30 minutes to 2 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 dispense with a catalyst. The catalyst may accelerate the reaction rate but may induce side reactions, so it is preferable not to use a catalyst. In order to make the reaction produce as much monoester as possible and produce little or no diester, an inhibitor such as triethylamine, pyridine, etc. may be added during the reaction to inhibit the production of diester.

The fatty alcohol may be selected from C₁～C₈Monohydric alcohols, preferably C₁～C₅Monohydric alcohols, such as methanol, ethanol, n-propanol, n-butanol, n-pentanol, and the like, most preferably C₁～C₂And monohydric alcohols such as methanol and ethanol. The molar ratio of the alkenyl succinic anhydride or alkenyl succinic acid to the fatty alcohol may be 1:0.5 to 1.2, preferably 1:0.8 to 1.1.

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。

Other additives such as flow improver, cetane improver, detergent dispersant, metal deactivator, preservative and the like can be contained in the diesel oil composition 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 and small addition amount, and can be used as the diesel antiwear agent to remarkably improve the lubricity of low-sulfur diesel and improve the corrosion resistance of the diesel.

Drawings

FIG. 1 is a mass spectrum of the antiwear agent product prepared in example 2, namely: is the addition peak of the mass spectrum of the sodium ion of the methyl oleate-based succinic acid monoester prepared by using methyl oleate, maleic anhydride and methanol as raw materials, wherein m/z is 449.29.

FIG. 2 is an IR spectrum of the antiwear product of example 2, wherein 2800cm^-1～3000cm^-1And 1450cm^-1Peaks indicate aliphatic hydrocarbon structure; 1781cm^-1The peak represents the ester carbonyl group adjacent to the carboxyl group; 1735cm^-1The peak represents the ester group at the long chain end; 1708cm^-1The peak represents a carboxylic acid; 1217cm^-1Nearby peaks indicate C-O structure; 3000cm^-1Near and 1640cm^-1The peaks near represent carbon-carbon double bonds.

Detailed Description

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

Example 1:

1500g of methyl oleate (96 percent by mass) and 500g of maleic anhydride (the molar ratio of methyl oleate to maleic anhydride is about 1:1) are placed in a 3000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, and 20g of anhydrous aluminum chloride (analytically pure, Shanghai Michelin Biochemical technology Co., Ltd.) is added as a reaction catalyst, wherein the dosage of the catalyst is 1 percent of the total mass of reactants. And introducing nitrogen for 5-10 minutes, heating and stirring to raise the temperature to 180 ℃, carrying out reflux reaction for 5 hours, removing excessive maleic anhydride through reduced pressure distillation, and removing anhydrous aluminum chloride to obtain the methyl oleate-based succinic anhydride reaction intermediate.

Cooling the reaction intermediate of the methyl oleate-based succinic anhydride to 60 ℃, putting 500g of the reaction intermediate of the methyl oleate-based succinic anhydride into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen gas introduction tube, adding 32.5g of methanol (the molar ratio of the alkenyl succinic anhydride to the fatty alcohol is 1:0.8), introducing nitrogen gas into the reactor for 5-10 minutes, stirring at constant temperature of 60 ℃, reacting for 0.5 hour, cooling to room temperature, and standing for 24 hours to obtain the monomethyl oleate succinate product.

Example 2:

1500g of methyl oleate (the mass fraction is 96 percent) and 745g of maleic anhydride (the molar ratio of methyl oleate to maleic anhydride is about 1:1.5) are placed in a 3000ml reactor 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 200 ℃, the reaction is carried out for 8 hours, and excess maleic anhydride is removed through reduced pressure distillation, so as to obtain the methyl oleate-based succinic anhydride reaction intermediate containing the following structural formula 2 or/and structural formula 3.

Cooling the reaction intermediate to 70 ℃, putting 500g of the reaction intermediate into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 40.6g of methanol (the molar ratio of alkenyl succinic anhydride to fatty alcohol is 1:1), introducing nitrogen for 5-10 minutes, stirring at constant temperature of 70 ℃, reacting for 2 hours, and cooling to obtain the methyl oleate succinic acid monomethyl ester product containing the following structural formula 4 or/and the structural formula 5.

Example 3:

1550g of ethyl oleate (the mass fraction is 98%) and 745g of maleic anhydride (the molar ratio of the ethyl oleate to the maleic anhydride is about 1:1.5) are placed in a 3000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen introduction tube, nitrogen is introduced for 5-10 minutes, the mixture is heated and stirred to 220 ℃, the temperature is raised for 10 hours, and excess maleic anhydride is removed through reduced pressure distillation to obtain an ethyl oleate-based succinic anhydride reaction intermediate.

Cooling the reaction intermediate of the ethyl oleate succinic anhydride to 80 ℃, putting 500g of the reaction intermediate into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen introduction tube, adding 71g of ethanol (the molar ratio of the alkenyl succinic anhydride to the fatty alcohol is 1:1.1), introducing nitrogen for 5-10 minutes, stirring at the constant temperature of 80 ℃, reacting for 3 hours, and cooling to obtain the ethyl oleate succinic acid monoethanol ester product.

Example 4:

1500g of methyl oleate (96% by mass) and 981g of maleic anhydride (the molar ratio of methyl oleate to maleic anhydride is about 1:2) are placed in a 3000ml reactor equipped with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, and about 12.5g of 2246 antioxidant (technical grade, Nanjing Ruiyi Yanhua plant) is added in an amount of about 0.5% of the total mass of the reactants. And introducing nitrogen for 5-10 minutes, heating, stirring, heating to 220 ℃, reacting for 8 hours, and removing excessive maleic anhydride through reduced pressure distillation to obtain the methyl oleate-based succinic anhydride reaction intermediate.

Cooling the reaction intermediate of the methyl oleate-based succinic anhydride to 90 ℃, then placing 500g of the reaction intermediate into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 48.8g of methanol (the molar ratio of the alkenyl succinic anhydride to the fatty alcohol is 1:1.2), introducing nitrogen for 5-10 minutes, stirring at the constant temperature of 90 ℃, reacting for 5 hours, and cooling to obtain the methyl oleate-based succinic acid monomethyl ester product.

Example 5:

310g of ethyl oleate (the mass fraction is 98 percent) and 294.5g of maleic anhydride (the molar ratio of the ethyl oleate to the maleic anhydride is about 1:3) are placed in a 1000ml reactor 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 240 ℃, the temperature is raised for reaction for 8 hours, and excess maleic anhydride is removed through reduced pressure distillation to obtain an ethyl oleate-based succinic anhydride reaction intermediate.

Cooling the reaction intermediate of the ethyl oleate succinic anhydride to 100 ℃, putting 300g of the reaction intermediate into a 500ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen introduction tube, adding 37.8g of n-propanol (the molar ratio of the alkenyl succinic anhydride to the fatty alcohol is 1:1), introducing nitrogen for 5-10 minutes, stirring at constant temperature of 100 ℃, reacting for 1 hour, cooling to room temperature, and standing for 24 hours to obtain the ethyl oleate succinic mono-n-propanol ester antiwear agent product.

Example 6:

placing 1500g of methyl oleate (the mass fraction is 98%) and 745g of maleic anhydride (the molar ratio of methyl oleate to maleic anhydride is about 1:1.5) in 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, heating and stirring to 220 ℃, reacting for 8 hours, and removing excessive maleic anhydride through reduced pressure distillation to obtain the methyl oleate based succinic anhydride reaction intermediate.

Cooling the intermediate of the methyl oleate succinic anhydride reaction to 70 ℃, putting 500g of the intermediate into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen introduction tube, adding 112g of n-amyl alcohol (the molar ratio of alkenyl succinic anhydride to fatty alcohol is 1:1), introducing nitrogen for 5-10 minutes, stirring at the constant temperature of 140 ℃, reacting for 5 hours, and cooling to room temperature to obtain the product of the methyl oleate succinic acid mono-n-amyl alcohol antiwear agent.

Example 7:

putting 120g of methyl erucate (the mass fraction is 90%), 60.2g of maleic anhydride (the molar ratio of the methyl erucate to the maleic anhydride is about 1:2) into a 250ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen introducing tube, introducing nitrogen for 5-10 minutes, heating and stirring to 225 ℃, reacting for 10 hours, and removing excessive maleic anhydride through reduced pressure distillation to obtain an erucyl succinic anhydride reaction intermediate.

Cooling the intermediate product of the erucic methyl ester succinic anhydride reaction to 70 ℃, putting 100g of the intermediate product into a 250ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 15.5g of methanol (the molar ratio of the alkenyl succinic anhydride to the methanol is 1:1.2), introducing nitrogen for 5-10 minutes, stirring at the constant temperature of 110 ℃, removing the methanol after carrying out reflux reaction for 4 hours, and cooling to room temperature to obtain the monomethyl erucic methyl ester succinate antiwear agent product.

Example 8:

1500g of oleic acid (85% by weight, manufactured by Toshiai chemical industry Co., Ltd.) and 781.5g of maleic anhydride (the molar ratio of oleic acid to maleic anhydride is about 1:1.5) were placed in a 3000ml reactor equipped with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, and about 11.4g of 2246 antioxidant (industrial grade, Nanjing Ruiyi chemical plant) was added in an amount of about 0.5% by weight based on the total mass of the reactants. And introducing nitrogen for 5-10 minutes, heating, stirring, heating to 170 ℃, reacting for 6 hours, and removing excessive maleic anhydride through reduced pressure distillation to obtain the oleic succinic anhydride reaction intermediate.

Cooling the oleic acid-based succinic anhydride reaction intermediate to 70 ℃, putting 500g of the oleic acid-based succinic anhydride reaction intermediate into a 1000ml reactor provided with an electric stirrer, a thermometer, a reflux cold energy tube and a nitrogen inlet tube, adding 50.6g of methanol (the molar ratio of the oleic acid-based succinic anhydride to the methanol is 1:1.2), introducing nitrogen for 5-10 minutes, stirring at the constant temperature of 80 ℃, removing the methanol after carrying out reflux reaction for 1 hour, and cooling to room temperature to obtain the oleic acid-based succinic acid monomethyl ester antiwear agent product.

Comparative example 1:

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

Comparative example 2:

oleic acid (85% by mass, tai xi ai (shanghai) chemical industry development limited).

Comparative example 3:

according to the patent CN106929112A, the method for improving the wear resistance of low-sulfur diesel oil comprises the steps of self-preparing 1-octadecenyl succinic anhydride, heating maleic anhydride, 1-octadecene and a small amount of p-hydroxyanisole under stirring to reflux under the protection of nitrogen, reacting at constant temperature, cooling to room temperature under the protection of nitrogen after the reaction is finished, and recovering unreacted raw materials and octadecenyl succinic anhydride products through reduced pressure distillation. 50g of octadecenyl succinic anhydride and 10g of absolute ethyl alcohol are placed in a three-neck flask reactor provided with an electric stirrer, a thermometer, a reflux water separator and a nitrogen inlet pipe, nitrogen is introduced to the reactor to be heated, stirred and refluxed, and the reaction is carried out for 12 hours by nitrogen purging to obtain the product, namely the octadecenyl succinic acid monoethyl ester.

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 hydrorefined 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 agents prepared in the examples and comparative examples of the present invention were added to low sulfur diesel oil to perform a lubricating property test, and the test results are 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. Especially, unexpected is that the effect of improving the lubricating property of the base diesel oil by the alkenyl succinic acid monomethyl ester and the alkenyl succinic acid monoethyl ester is most obvious and is far better than that of the alkenyl succinic acid monopropyl ester or the alkenyl succinic acid monopentyl ester.

Example 10 Corrosion test

This example shows the corrosive effect of the products of examples 1-3 and the additives of comparative examples 1 and 2 added to diesel fuel in an amount of 200 mg/kg, as shown in Table 3^-1The test method is GB/T11143.

TABLE 3 improvement of Corrosion behaviour of anti-wear agents on diesel

As can be seen from Table 3, the additive provided by the invention (example 2 and example 3) has a great improvement effect on diesel oil rust, and the effect is obviously better than that of methyl oleate (comparative example 1) and oleic acid (comparative example 2).

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.