CN110041985B - Composite nano lubricating oil additive with self-repairing function and preparation method thereof - Google Patents

Abstract

The invention discloses a composite nano lubricating oil additive with a self-repairing function and a preparation method thereof, belonging to the technical field of lubricating oil. The lubricating oil additive comprises the following components in parts by mass: 20-30 parts of modified composite nano particles, 10-20 parts of superfine mineral micro powder, 5-10 parts of sodium alkyl benzene sulfonate, 3-6 parts of an antiwear agent and 3-5 parts of a preservative. Aiming at the problems of easy agglomeration and poor dispersibility of the nano particle additive in the prior art, the copper particles, nano titanium dioxide, graphite with a sheet structure and boron nitride are selected as the nano particle additive, the nano particle additive is modified by adopting oleic acid coating, ultrasonic dispersion and high-speed ball milling, and superfine mineral micro powder is used as an auxiliary material, so that surface scratches can be quickly and effectively filled, mechanical damage can be repaired, the copper particles, the nano titanium dioxide, the graphite with the sheet structure and the boron nitride with the sheet structure are mutually matched, the lubricating effect of lubricating oil is improved, the service life of the lubricating oil is prolonged, and the anti-abrasion effect is obvious.

Description

Composite nano lubricating oil additive with self-repairing function and preparation method thereof

Technical Field

The invention belongs to the technical field of lubricating oil, and particularly relates to a composite nano lubricating oil additive with a self-repairing function and a preparation method thereof.

Background

Friction wear is one of the most important forms of material and equipment damage and failure, and how to effectively control friction, reduce wear and improve lubricating performance becomes an important measure for saving energy and materials and shortening maintenance time. Lubricants are currently the most effective means of reducing friction and wear, while the use of additives is the most important and effective way to improve oil performance. However, the conventional anti-wear additive contains S, Cl and the like which are elements that not only corrode a machine but also pollute the environment. Therefore, research and development of energy-saving, pollution-free and efficient additives to replace the original additives is always the direction of continuous research of researchers. In recent years, nanoparticles as lubricating oil additives have been paid attention to by researchers at home and abroad due to good functions of friction reduction, wear resistance, extrusion and self-repair.

The nano science and technology is considered as a new technology facing the 21 st century, and the excellent characteristics of the nano science and technology attract the wide attention of researchers. In recent years, nano materials show important application value and wide application prospect in the fields of light, electricity, magnetism and the like, and meanwhile, the nano particles have excellent characteristics which are not possessed by a plurality of traditional conventional materials, so that the nano particles show special and excellent physicochemical properties and enter the visual field of people. The nano particles are used as lubricating oil additives, and the advantages are mainly reflected in the following three aspects: the diffusion capacity and the self-diffusion capacity of the nano particles are stronger, and a permeable layer or a diffusion layer with good wear resistance is easily formed on the surface of the metal, so that the friction-reducing and wear-resisting effects are achieved; secondly, the nano particles have the characteristic of small particle size, are approximately spherical in shape, can roll between friction pairs, play a role similar to a ball bearing, and change the friction form from sliding friction to rolling friction so as to reduce the friction coefficient; and thirdly, the nano particles can polish and strengthen the friction surface and support the external load, so that the bearing capacity is improved. However, the existing nano particles used as the lubricating oil additive have single function, are agglomerated and are unevenly dispersed in the base oil, so that the wear-resistant and wear-reducing effects are poor and the good lubricating effect cannot be achieved.

Disclosure of Invention

In order to solve the problems of poor dispersing effect, easy agglomeration and single function of the nano particle additive in the prior art, the invention provides the composite nano lubricating oil additive with good dispersing property and self-repairing function, and discloses a specific preparation method thereof.

The technical scheme adopted by the invention is as follows:

a composite nano lubricating oil additive with a self-repairing function comprises the following components in parts by mass: 20-30 parts of modified composite nano particles, 10-20 parts of superfine mineral micro powder, 5-10 parts of sodium alkyl benzene sulfonate, 3-6 parts of an antiwear agent and 3-5 parts of a preservative.

The modified composite nano particle is prepared by the following method:

(1) respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 3-5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying for 24 hours at 50 ℃ in a vacuum drier to obtain the modified composite nanoparticles.

Preferably, the composite nanoparticles in the step (2) are prepared by mixing nano titanium dioxide, nano graphite powder and nano boron nitride according to the mass ratio of 1:3: 1.

Preferably, the planetary ball mill in the step (3) has a rotation speed of 250 rpm.

Preferably, the superfine mineral micro powder is obtained by mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1 and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture with the average particle size of 70-100 nm.

Preferably, the preservative is zinc dialkyldithiocarbamate or molybdenum dialkyldithiocarbamate.

Preferably, the antiwear agent is sulfurized isobutylene or sodium metaborate.

A preparation method of a composite nano lubricating oil additive with a self-repairing function comprises the following steps:

(1) preparing modified composite nano particles: respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 3-5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying the product for 24 hours at 50 ℃ in a vacuum drier to obtain modified composite nanoparticles;

(4) mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1, and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture, wherein the average particle size of the mixture is 70-100nm, so as to obtain superfine mineral micro powder;

(5) the modified composite nano particles, the superfine mineral micro powder, the sodium alkyl benzene sulfonate, the antiwear agent and the preservative are uniformly mixed according to the parts by weight, and the additive is obtained after ball milling by a planetary ball mill, wherein the rotating speed of the ball mill is 80 revolutions per minute, and the ball milling is carried out for 1 hour.

The amount of the lubricating oil additive is that 98 parts of lubricating oil is added with 2 parts of the lubricating oil additive.

The raw materials used in the present invention are commercially available.

Has the advantages that:

aiming at the problems of easy agglomeration and poor dispersibility of the nano particle additive in the prior art, the invention selects copper particles, nano titanium dioxide, graphite with a sheet structure and boron nitride as the nano particle additive, and modifies the nano particle additive by adopting oleic acid coating, ultrasonic dispersion and telling ball milling modes, wherein the long carboxyl chain of oleic acid and Cu are²⁺Combine to form the fatty acid salt, and adsorb on the surface of nano particle with the form of ionic bond, make the inter particle distance grow, the interaction reduces, assist ultrasonic dispersion and ball-milling, the reunion phenomenon of at utmost alleviates the nano particle, graphite and boron nitride that have the lamellar structure in addition, make the Cu particle can form the membrane fast in mechanical friction process, assist superfine mineral miropowder, can effectively fill the surface mar fast, in order to restore mechanical damage, both interact, in order to increase the lubricating effect of lubricating oil, prolong lubricating oil life, the antifriction antiwear effect is showing.

Drawings

The ultraviolet absorption spectrum of the sample of FIG. 1 changes with standing time.

FIG. 2 is a surface topography of a sample, 1 before repair and 2 after repair.

Detailed Description

The technical solution of the present invention is further described below with reference to specific embodiments, but is not limited thereto.

Example 1

A composite nano lubricating oil additive with a self-repairing function comprises the following components in parts by mass: 20 parts of modified composite nano particles, 10 parts of superfine mineral micro powder, 5 parts of sodium alkyl benzene sulfonate, 3 parts of an antiwear agent and 3 parts of a preservative.

The modified composite nano particle is prepared by the following method:

(1) respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 3-5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying for 24 hours at 50 ℃ in a vacuum drier to obtain the modified composite nanoparticles.

The composite nano particles in the step (2) are prepared by mixing nano titanium dioxide, nano graphite powder and nano boron nitride according to the mass ratio of 1:3: 1.

The rotating speed of the planetary ball mill in the step (3) is 250 r/min.

The superfine mineral micro powder is obtained by mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1 and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture with the average particle size of 70-100 nm.

The preservative is zinc dialkyl dithiocarbamate.

The antiwear agent is sulfurized isobutylene.

A preparation method of a composite nano lubricating oil additive with a self-repairing function comprises the following steps:

(1) preparing modified composite nano particles: respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 3 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying the product for 24 hours at 50 ℃ in a vacuum drier to obtain modified composite nanoparticles;

(4) mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1, and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture, wherein the average particle size of the mixture is 70-100nm, so as to obtain superfine mineral micro powder;

(5) the modified composite nano particles, the superfine mineral micro powder, the sodium alkyl benzene sulfonate, the antiwear agent and the preservative are uniformly mixed according to the parts by weight, and the additive is obtained after ball milling by a planetary ball mill, wherein the rotating speed of the ball mill is 80 revolutions per minute, and the ball milling is carried out for 1 hour.

The amount of the lubricating oil additive is that 98 parts of lubricating oil is added with 2 parts of the lubricating oil additive.

Example 2

A composite nano lubricating oil additive with a self-repairing function comprises the following components in parts by mass: 25 parts of modified composite nano particles, 15 parts of superfine mineral micro powder, 8 parts of sodium alkyl benzene sulfonate, 5 parts of an antiwear agent and 4 parts of a preservative.

The modified composite nano particle is prepared by the following method:

(1) respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 3-5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying for 24 hours at 50 ℃ in a vacuum drier to obtain the modified composite nanoparticles.

The composite nano particles in the step (2) are prepared by mixing nano titanium dioxide, nano graphite powder and nano boron nitride according to the mass ratio of 1:3: 1.

The rotating speed of the planetary ball mill in the step (3) is 250 r/min.

The superfine mineral micro powder is obtained by mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1 and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture with the average particle size of 70-100 nm.

The preservative is molybdenum dialkyl dithiocarbamate.

The antiwear agent is sodium metaborate.

A preparation method of a composite nano lubricating oil additive with a self-repairing function comprises the following steps:

(1) preparing modified composite nano particles: respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 4 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying the product for 24 hours at 50 ℃ in a vacuum drier to obtain modified composite nanoparticles;

(4) mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1, and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture, wherein the average particle size of the mixture is 70-100nm, so as to obtain superfine mineral micro powder;

(5) the modified composite nano particles, the superfine mineral micro powder, the sodium alkyl benzene sulfonate, the antiwear agent and the preservative are uniformly mixed according to the parts by weight, and the additive is obtained after ball milling by a planetary ball mill, wherein the rotating speed of the ball mill is 80 revolutions per minute, and the ball milling is carried out for 1 hour.

The amount of the lubricating oil additive is that 98 parts of lubricating oil is added with 2 parts of the lubricating oil additive.

Example 3

A composite nano lubricating oil additive with a self-repairing function comprises the following components in parts by mass: 30 parts of modified composite nano particles, 20 parts of superfine mineral micro powder, 10 parts of sodium alkyl benzene sulfonate, 6 parts of an antiwear agent and 5 parts of a preservative.

The modified composite nano particle is prepared by the following method:

(1) respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 3-5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying for 24 hours at 50 ℃ in a vacuum drier to obtain the modified composite nanoparticles.

The composite nano particles in the step (2) are prepared by mixing nano titanium dioxide, nano graphite powder and nano boron nitride according to the mass ratio of 1:3: 1.

The rotating speed of the planetary ball mill in the step (3) is 250 r/min.

The superfine mineral micro powder is obtained by mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1 and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture with the average particle size of 70-100 nm.

The preservative is molybdenum dialkyl dithiocarbamate.

The antiwear agent is sulfurized isobutylene.

A preparation method of a composite nano lubricating oil additive with a self-repairing function comprises the following steps:

(1) preparing modified composite nano particles: respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying the product for 24 hours at 50 ℃ in a vacuum drier to obtain modified composite nanoparticles;

(4) mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1, and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture, wherein the average particle size of the mixture is 70-100nm, so as to obtain superfine mineral micro powder;

(5) the modified composite nano particles, the superfine mineral micro powder, the sodium alkyl benzene sulfonate, the antiwear agent and the preservative are uniformly mixed according to the parts by weight, and the additive is obtained after ball milling by a planetary ball mill, wherein the rotating speed of the ball mill is 80 revolutions per minute, and the ball milling is carried out for 1 hour.

The amount of the lubricating oil additive is that 98 parts of lubricating oil is added with 2 parts of the lubricating oil additive.

Comparative example 1

A composite nano lubricating oil additive with a self-repairing function comprises the following components in parts by mass: 30 parts of composite nano particles, 20 parts of superfine mineral micro powder, 10 parts of sodium alkyl benzene sulfonate, 6 parts of an antiwear agent and 5 parts of a preservative.

The composite nano particles are prepared by mixing nano titanium dioxide, nano graphite powder and nano boron nitride according to the mass ratio of 1:3: 1.

The superfine mineral micro powder is obtained by mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1 and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture with the average particle size of 70-100 nm.

The preservative is molybdenum dialkyl dithiocarbamate.

The antiwear agent is sulfurized isobutylene.

A preparation method of a composite nano lubricating oil additive with a self-repairing function comprises the following steps:

(1) mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1, and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture, wherein the average particle size of the mixture is 70-100nm, so as to obtain superfine mineral micro powder;

(2) the composite nano particles, the superfine mineral micro powder, the sodium alkyl benzene sulfonate, the antiwear agent and the preservative are uniformly mixed according to the parts by weight, and the additive is obtained after ball milling by a planetary ball mill, wherein the rotating speed of the ball mill is 80 revolutions per minute, and the ball milling is carried out for 1 hour.

The amount of the lubricating oil additive is that 98 parts of lubricating oil is added with 2 parts of the lubricating oil additive.

The formulation of this example is the same as that of example 3, except that commercially available finished nanoparticles are used, i.e., no modification is made.

Comparative example 2

A composite nano lubricating oil additive with a self-repairing function comprises the following components in parts by mass: 30 parts of modified composite nano particles, 10 parts of sodium alkyl benzene sulfonate, 6 parts of an antiwear agent and 5 parts of a preservative.

The modified composite nano particle is prepared by the following method:

(1) respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 3-5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying for 24 hours at 50 ℃ in a vacuum drier to obtain the modified composite nanoparticles.

The composite nano particles in the step (2) are prepared by mixing nano titanium dioxide, nano graphite powder and nano boron nitride according to the mass ratio of 1:3: 1.

The rotating speed of the planetary ball mill in the step (3) is 250 r/min.

The preservative is molybdenum dialkyl dithiocarbamate.

The antiwear agent is sulfurized isobutylene.

A preparation method of a composite nano lubricating oil additive with a self-repairing function comprises the following steps:

(1) preparing modified composite nano particles: respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying the product for 24 hours at 50 ℃ in a vacuum drier to obtain modified composite nanoparticles;

(4) the modified composite nano particles, sodium alkyl benzene sulfonate, an antiwear agent and a preservative are uniformly mixed according to the parts by weight, and the additive is obtained after ball milling by a planetary ball mill, wherein the rotating speed of the ball mill is 80 revolutions per minute, and the ball milling is carried out for 1 hour.

The amount of the lubricating oil additive is that 98 parts of lubricating oil is added with 2 parts of the lubricating oil additive.

The formulation of this example is the same as example 3 except that the ultra fine mineral powder is not used.

Test experiments

Taking base oil produced by exxon Mobil chemical industry as lubricating oil, and mixing the following raw materials in parts by weight: the lubricant additive obtained in the examples 1-3 and the comparative examples 1-2 of the present invention was added in a weight ratio of 98:2, respectively, the comparative example 3 was set, and commercially available copper nanoparticles were added as an additive (Suzhou Changhu nanotechnology Co., Ltd., base oil: copper powder: 98: 2); comparative example 4 (lubricant additive application No. 200710121988.7 was used as per the specification), a blank control was set and set, i.e., no additive was added, stirred and mixed well, and after standing for 72 hours, the lubricant morphology was observed. Then respectively carrying out ultrasonic treatment for 4h, centrifuging at 2000r/min for 30min, standing for 72h, observing the form of the lubricating oil again, and recording the experimental results as shown in the following table 1:

TABLE 1 Dispersion test results

As can be seen from the data in the table, the lubricating oils using the additives obtained in examples 1 to 3 of the present invention are uniform and stable and have good stability, while comparative examples 1 to 4 show different degrees of stratification after standing and subsequent ultrasonic treatment.

The UV absorption spectra of the lubricants obtained in examples, comparative examples 1 to 4 and blank control were also measured with time using a spectrophotometer. Each substance has a different molecular, atomic and molecular structure and a different ability to absorb light energy, so that the substance has a fixed, characteristic absorption spectrum curve, and the content of the substance can be determined according to the level of absorbance at certain characteristic wavelengths in the absorption spectrum. The specific experimental result is shown in figure 1, and it can be seen from the figure that the ultraviolet absorption intensity of the comparative examples 1-4 is obviously reduced and the absorbance in the visible light region is gradually increased along with the prolonging of the standing time, which indicates that the particles in the oil liquid are precipitated. The oil samples of the examples have small changes in ultraviolet absorption intensity and absorbance with the lapse of the standing time, which indicates that the particles can be stably dispersed in the oil.

Meanwhile, the lubricating oil additive obtained in the embodiments 1 to 3 of the invention is subjected to tribology performance test and self-repairing test.

Measuring the maximum non-seizing load PB value and the wear-mark diameter D of the composite powder according to a GB/T3142-1982 lubricant carrying capacity measuring method (a four-ball method); long-term wear tests were carried out according TO SH/TO189-1992 lubricating oil antiwear performance test method (four-ball method); the specimens were observed for plaque with an optical microscope.

	PB/N	D/mm
			Example 1	471	0.331
Example 2	476	0.330
			Example 3	477	0.330
Comparative example 1	432	0.348
			Comparative example 2	435	0.345
Comparative example 3	425	0.362
			Comparative example 4	426	0.366
Blank control	352	0.379

The self-repairing experimental method comprises the following steps: the material of the sample plate under the experiment is Gr15 steel, and the material of the upper sample pin is common grey cast iron HT 250. In this experiment, a wear test was carried out for 4 hours under a load of 400N using a base oil, and after the completion of the test, a wear test was carried out for 6 hours using a lubricating oil containing the additive obtained in example 3 in the same area of the same plate. The self-repairing performance is explored by comparing the change of the friction appearance before and after repairing. As shown in fig. 2, the surface topography before and after repair is obtained by trial and error, it can be seen that before repair, the wear scar on the surface of the sample is obvious, after lubrication treatment, the surface depression is obviously reduced, and it can be seen that the surface of the sample is effectively filled with the nanoparticles, so that the friction is reduced, the wear is reduced, and the self-repairing capability of the machine is improved.

It should be noted that the above-mentioned embodiments are only some of the preferred modes for implementing the invention, and not all of them. Obviously, all other embodiments obtained by persons of ordinary skill in the art based on the above-mentioned embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

Claims (5)

1. The composite nano lubricating oil additive with the self-repairing function is characterized by comprising the following components in parts by mass: 20-30 parts of modified composite nano particles, 10-20 parts of superfine mineral micro powder, 5-10 parts of sodium alkyl benzene sulfonate, 3-6 parts of an antiwear agent and 3-5 parts of a preservative;

the modified composite nano particle is prepared by the following method:

respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

washing the copper hydroxide suspension obtained in the step (1) for 3-5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying the product for 24 hours at 50 ℃ in a vacuum drier to obtain modified composite nanoparticles;

the superfine mineral micro powder is obtained by mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1 and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture with the average particle size of 70-100 nm;

the composite nano particles in the step (2) are prepared by mixing nano titanium dioxide, nano graphite powder and nano boron nitride according to the mass ratio of 1:3: 1.

2. The composite nano lubricating oil additive with self-repairing function according to claim 1, wherein the planetary ball mill in the step (3) rotates at a speed of 250 rpm.

3. The composite nano-lubricating oil additive with self-repairing function of claim 1, wherein the corrosion inhibitor is zinc dialkyl dithiocarbamate or molybdenum dialkyl dithiocarbamate.

4. The composite nano-lubricating oil additive with self-repairing function of claim 1, wherein the antiwear agent is sulfurized isobutylene or sodium metaborate.

5. A method for preparing the composite nano lubricating oil additive with the self-repairing function according to any one of claims 1 to 4, is characterized by comprising the following steps:

(1) preparing modified composite nano particles: respectively weighing copper chloride and sodium hydroxide, preparing aqueous solutions with the molar concentrations of 3mol/L and 3mol/L, and gradually dripping the sodium hydroxide solution while stirring the copper chloride solution according to the volume ratio of 1:5 to obtain a uniform copper hydroxide suspension;

(2) washing the copper hydroxide suspension obtained in the step (1) for 3-5 times by using deionized water, and then mixing the copper hydroxide suspension and the deionized water according to a solid-to-liquid ratio of 1 g: adding 3ml of composite nanoparticles, stirring for 24 hours to obtain a mixed solution A, adding a formic acid solution with the volume concentration of 30 percent, which is twice the volume of the mixed solution A, into the mixed solution A in the stirring process, and continuously stirring for 12 hours to obtain a mixture B;

(3) mixing and stirring oleic acid, petroleum ether and the mixture B uniformly according to the volume ratio of 1:1:1, adding and performing ultrasonic reaction for 5 hours at 80 ℃, performing ball milling for 12 hours in a planetary ball mill, performing centrifugal separation on the obtained product, and drying the product for 24 hours at 50 ℃ in a vacuum drier to obtain modified composite nanoparticles;

(4) mixing palygorskite powder and silicon dioxide powder according to the mass ratio of 1:1, and performing ball milling for 24 hours at the rotating speed of 300 r/m to obtain a mixture, wherein the average particle size of the mixture is 70-100nm, so as to obtain superfine mineral micro powder;

(5) uniformly mixing the modified composite nanoparticles, the superfine mineral micropowder, sodium alkyl benzene sulfonate, an antiwear agent and a preservative in parts by weight, and carrying out ball milling by using a planetary ball mill for 1 hour, wherein the rotating speed of the ball mill is 80 rpm.

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