Preparation method of nano-diamond lubricating oil

Abstract

The invention discloses a preparation method of nano-diamond lubricating oil, the nano-diamond lubricating oil comprises nano-diamond lubricating oil raw materials, and the nano-diamond lubricating oil raw materials comprise 3.2% of nano-diamond particles, 22% of fatty glyceride, 36% of octylphenol polyoxyethylene ether and 38.8% of lubricating base oil. The preparation method of the nano-diamond lubricating oil comprises the following steps: sorting nano-diamond particles, and modifying the surface of the nano-diamond; carrying out high-speed crushing treatment on the modified nano diamond particles; the nano-diamond is ultrasonically stirred and mixed with fatty glyceride, octylphenol polyoxyethylene ether and lubricating base oil, and the nano-diamond lubricating oil product is obtained. According to the preparation method of the nano-diamond lubricating oil, the surface of the nano-diamond is modified to prevent the nano-diamond from being mixed with the lubricating base oil to generate precipitation and agglomeration, and the preparation stability of the lubricating oil is improved.

Description

Technical Field

[0001] The invention relates to the technical field of lubricating oil preparation, in particular to a method for preparing nano-diamond lubricating oil. Background Art

[0002] Nano diamonds were developed more than 30 years ago, but their application was limited to abrasives such as polycrystalline and polishing agents. With the deepening of people's understanding of the properties of nano diamonds, nano diamonds have begun to be used in lubricating oils, metal coatings, magnetic recording systems, medicine and other fields, and the application fields are still expanding. Nano diamond black powder is synthesized by mixing and forming negative oxygen balance high-energy explosives and then detonating. When the explosives are detonated under air-tight conditions, the unoxidized excess free carbon crystallizes into nano diamond particles in the high temperature and ultra-high pressure environment of the detonation zone. After removing impurities, nano diamond black powder is obtained. The nano diamond black powder is spherical, with diamond at the center, accounting for about 60%, and graphite on the spherical surface, accounting for about 40%, with an average particle size of 7nm.

[0003] At present, all high- and medium-end lubricant additives are liquid organic derivatives containing sulfur, phosphorus, chlorine and terpenes, and they all have good lubrication properties. However, as they are organic substances, they are not resistant to high temperatures and extreme pressures, have short lifespans and cause environmental pollution. Therefore, the international lubricant industry authorities unanimously hope to replace organic derivative lubricant additives with inorganic solid additives, such as graphite, molybdenum disulfide and diamonds. However, since large-particle solid lubricants will precipitate and block the oil circuit, this wish was not realized until the emergence of nanodiamonds.

[0004] The preparation method of nano-diamond lubricating oil in the prior art, such as the formula of nano-diamond lubricating oil for vehicles and ships with application number CN202010571041.1, has a technical scheme as follows: the following substances are mixed by weight: 28-32 parts of 150N lubricating oil base oil, 40-45 parts of 500N lubricating oil base oil, 7-10 parts of 150BS lubricating oil base oil, 8-10 parts of tackifier, 0.2-0.4 parts of pour point depressant, and 1.2-1.5 parts of nano-diamond emulsion. In the prior art, there is a nano-diamond automatic repair fluid, such as a nano-diamond automatic repair fluid for a piston engine with application number CN201410167800.2, and its technical scheme is as follows: comprising the following preparation steps: adding nano-diamonds to a dispersant OP-10, stirring for more than 20 minutes, and then standing, after the bubbles completely disappear, a black precipitate appears at the bottom, and pouring out the supernatant; wherein the nano-diamonds are spherical particles with a particle size of 2-4nm, and the addition ratio of the OP-10 to the nano-diamonds is 0.8-1.2mg of nano-diamonds per 1LOP-10; adding the above supernatant to lubricating oil, stirring and mixing to obtain an automatic repair fluid, wherein the mass percentage of the supernatant to the lubricating oil is 10%-30%:90%-70%.

[0005] However, the volume density of nanodiamonds is higher than that of lubricating oil. Therefore, nanodiamonds added to lubricating oil will produce precipitation and agglomeration, and cannot be dispersed stably in every drop of lubricating oil for a long time. The high dispersibility of nanodiamonds cannot be effectively modified to make them stable.

[0006] In view of this, we conducted in-depth research on the above issues, which led to the present case.

[0007] In view of the above problems, an innovative design is carried out based on the original preparation method of nano-diamond lubricant. Summary of the invention

[0008] The purpose of the present invention is to provide a method for preparing nano-diamond lubricating oil to solve the problem in the above background technology that the high dispersion of nano-diamonds mixed with lubricating oil is prone to precipitation and agglomeration, affecting stability.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A method for preparing a nano-diamond lubricating oil comprises a nano-diamond lubricating oil raw material, wherein the nano-diamond lubricating oil raw material comprises nano-diamond particles, fatty acid glyceride, octylphenol polyoxyethylene ether and lubricating base oil, and the nano-diamond lubricating oil raw material comprises 3.2% of nano-diamond particles, 22% of fatty acid glyceride, 36% of octylphenol polyoxyethylene ether and 38.8% of lubricating base oil. The method for preparing the nano-diamond lubricating oil comprises the following steps:

[0011] Step 1, sorting the nano-diamond particles and modifying the surface of the nano-diamond;

[0012] Step 2, subjecting the nano-diamond particles modified in step 1 to high-speed crushing;

[0013] Step three, mixing the nano-diamond powder with fatty acid glyceride, octylphenol polyoxyethylene ether and lubricating base oil by ultrasonic stirring to obtain a nano-diamond lubricating oil product.

[0014] Preferably, the specific steps of step 1 are: using double distilled deionized water as a dispersant medium, and utilizing solid phase grafting of a silylation reaction to modify the surface of the nano-diamond particles.

[0015] The above technical scheme is adopted to modify the surface of nanodiamond by silylation reaction, which has high atom economy, small impact on the environment, easy storage and operation of organosilicon reagents, low toxicity, mild reaction conditions, high yield and selectivity, and good tolerance to other functional groups.

[0016] Preferably, the specific steps of step one are: reacting trimethylchlorosilane, trimethylsulfoxonium iodide and double distilled deionized water, the reaction ensures the silylation process of hydroxyl group under the participation of water, and the molar ratio of trimethylchlorosilane and trimethylsulfoxonium iodide is 1:1.

[0017] By adopting the above technical scheme, the silylation reaction has the characteristics of high atom economy, which means that the raw materials used in the reaction process can be efficiently converted into the target product, reducing the generation of waste and placing less burden on the environment.

[0018] Preferably, the specific steps of step 1 are: filling the mixture generated by the silylation reaction into a flask, adding nano-diamond particles in small amounts and multiple times to mix, heating the suspension obtained from the mixture to boiling for 5 hours, cooling and leaving it for 12 hours, distilling the residue of the silyl mixture from the mixture, heating the remaining solid at 300° C. in a vacuum for 5 hours, and obtaining modified nano-diamond particles.

[0019] By adopting the above technical scheme, the silylation reaction has good tolerance to other functional groups, and can reduce the high dispersion properties of nanodiamonds while maintaining the functional group activity of nanodiamonds, thereby reducing precipitation and agglomeration during mixing with lubricating oil base oil.

[0020] Preferably, the specific steps of step 2 are: preheating the nano-diamond particles obtained in step 1 to 430° C. in a high vacuum environment of 1.33×10-4 Pa for 4 hours and then cooling.

[0021] Using the above technical solution, since nanodiamond has extremely high wear resistance and corrosion resistance, and the compressive strength of nanodiamond is as high as 150GPa or more, it can withstand extremely high pressure. When it needs to be modified and crushed, it needs to be treated in a high vacuum environment and heated to facilitate the crushing process.

[0022] Preferably, the specific steps of step 2 are: adding a grinding aid to the cooled nano-diamond particles, and then grinding them using a high-speed grinding ball mill.

[0023] By adopting the above technical scheme, the powder is ultrafinely ground and surface modified by ultrafine grinding mechanochemistry, and the powder can be further ultrafine and functionalized in combination with grinding aids. As the ultrafine grinding proceeds, the agglomerates are continuously disintegrated into small agglomerates, and unsaturated valence and charged structure units appear on the surface of single particles, so that the particles are in a stable high-energy state.

[0024] Preferably, the specific steps of step 2 are: treating the nano-diamond powder obtained by high-speed ball mill crushing at a pressure of about 10-4Pa and a desorption temperature of 35°C for 4 hours, treating it in an ultrasonic ring, and obtaining a stable suspension of nano-diamonds with a size of 18-32nm in an aqueous medium.

[0025] By adopting the above technical solution, the modified nanodiamond has a substantial change, and it is possible to obtain a stable nanodiamond suspension in a non-aqueous medium. The modified nanodiamond has improved dispersibility and is better than the dispersibility in an aqueous solution.

[0026] Preferably, the specific steps of step three are: adding lubricating base oil to the nano-diamond suspension obtained in step two and stirring and mixing, and adding 0.1-0.2 parts of the nano-diamond suspension to 1000 parts of the lubricating oil.

[0027] By adopting the above technical solution, the modified nano-diamond suspension with improved dispersibility can be more easily mixed in the lubricating base oil, thereby preventing the nano-diamond suspension from precipitating and agglomerating.

[0028] Preferably, the specific steps of step three are: adding 22% fatty acid glyceride and 36% octylphenol polyoxyethylene ether to the mixed solution of lubricating oil and nano-diamond suspension, placing the mixed solution in an ultrasonic container for 20 minutes, and then heating the mixed solution to 80° C. for shear stirring to obtain a nano-diamond lubricating oil product.

[0029] By adopting the above technical scheme, the fatty acid glyceride in the raw material preparation hardly undergoes hydrolysis in neutral water and is slightly acidic. This stability enables the fatty acid glyceride to maintain its structural and functional integrity under a variety of environments. In addition, octylphenol polyoxyethylene ether is also easily soluble in oil and other organic solvents and has good emulsifying properties.

[0030] Compared with the prior art, the invention has the following beneficial effects: the preparation method of the nano-diamond lubricating oil is

[0031] 1. The surface of nano-diamond is modified by silylation reaction. Secondary distilled deionized water is used as a dispersant medium. The surface of nano-diamond particles is modified by solid phase grafting of silylation reaction. Trimethylchlorosilane, trimethylsulfoxonium iodide and secondary distilled deionized water are reacted. The reaction ensures the silylation process of hydroxyl groups under the participation of water. The surface of nano-diamond is modified by silylation reaction. It has high atomic economy and small impact on the environment. The organosilicon reagent is easy to store and operate, has low toxicity, and has mild reaction conditions, high yield and selectivity, and good tolerance to other functional groups. It can reduce the high dispersion properties of nano-diamond while maintaining the functional group activity of nano-diamond, so as to reduce precipitation and agglomeration during mixing with lubricating oil base oil.

[0032] 2. Heat and crush the nano-diamonds, add grinding aids to the heated and cooled nano-diamond particles, and then crush them using a high-speed ball mill. Use ultrafine grinding mechanochemistry to ultrafinely grind and modify the powder surface. The powder can be further ultrafine and functionalized with the grinding aid. As the ultrafine grinding proceeds, the agglomerates continue to disintegrate into small agglomerates, and unsaturated valence and units with charge structures appear on the surface of single particles, making the particles in a stable high-energy state. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a flow chart of the preparation method of nano-diamond lubricating oil. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1 , the present invention provides a technical solution:

[0036] A method for preparing a nano-diamond lubricating oil comprises a nano-diamond lubricating oil raw material, wherein the nano-diamond lubricating oil raw material comprises nano-diamond particles, fatty acid glyceride, octylphenol polyoxyethylene ether and lubricating base oil, and the nano-diamond lubricating oil raw material comprises 3.2% of nano-diamond particles, 22% of fatty acid glyceride, 36% of octylphenol polyoxyethylene ether and 38.8% of lubricating base oil. The method for preparing the nano-diamond lubricating oil comprises the following steps:

[0037] Step 1, sorting the nano-diamond particles and modifying the surface of the nano-diamond;

[0038] Step 2, subjecting the nano-diamond particles modified in step 1 to high-speed crushing;

[0039] Step three, mixing the nano-diamond powder with fatty acid glyceride, octylphenol polyoxyethylene ether and lubricating base oil by ultrasonic stirring to obtain a nano-diamond lubricating oil product.

[0040] The specific steps of step one are: using double distilled deionized water as a dispersant medium, and using solid phase grafting of silylation reaction to modify the surface of nano-diamond particles. The specific steps of step one are: reacting trimethylchlorosilane, trimethylsulfoxonium iodide and double distilled deionized water, the reaction ensures the silylation process of hydroxyl groups under the participation of water, and the molar ratio of trimethylchlorosilane and trimethylsulfoxonium iodide is 1:1. The specific steps of step one are: filling the mixture generated by the silylation reaction into a flask, adding nano-diamond particles in small amounts and multiple times to mix, heating the suspension obtained by the mixture to boiling, the heating time is 5 hours, cooling and placing for 12 hours, fractionating the residue of the silylation mixture from the mixture, and heating the remaining solid at 300°C in a vacuum for 5 hours to obtain modified nano-diamond particles. The silylation reaction is used to modify the surface of nanodiamonds. It has high atom economy, low impact on the environment, easy storage and operation of organosilicon reagents, low toxicity, mild reaction conditions, high yield and selectivity, and good tolerance to other functional groups. The silylation reaction has the characteristics of high atom economy, which means that the raw materials used in the reaction process can be efficiently converted into the target product, reducing the generation of waste and less burden on the environment. The silylation reaction has good tolerance to other functional groups and can reduce the high dispersion properties of nanodiamonds while maintaining the functional group activity of nanodiamonds, so as to reduce precipitation and agglomeration during mixing with lubricant base oil.

[0041] The specific steps of step 2 are: preheating the nano-diamond particles obtained in step 1 to 430°C in a high vacuum environment of 1.33x10-4Pa, heating for 4 hours and then cooling. The specific steps of step 2 are: adding a grinding aid to the cooled nano-diamond particles, and then crushing them using a high-speed crushing ball mill. The specific steps of step 2 are: treating the nano-diamond powder obtained by the high-speed crushing ball mill at a pressure of about 10-4Pa and a desorption temperature of 35°C for 4 hours, treating it in an ultrasonic ring, and obtaining a stable suspension of nano-diamonds with a size of 18-32nm in an aqueous medium. Since nano-diamonds have extremely high wear resistance and corrosion resistance, the compressive strength of nano-diamonds is as high as 150GPa or more, and they can withstand extremely high pressures. When they need to be modified and crushed, they need to be treated in a high vacuum environment and heated to facilitate crushing. The ultrafine grinding mechanochemistry is used to implement ultrafine grinding and surface modification of powders. The powders can be further ultrafine and functionalized with the aid of grinding. As the ultrafine grinding proceeds, the agglomerates are continuously deagglomerated into small agglomerates, and unsaturated valence and units with charge structures appear on the surface of single particles, making the particles in a stable high-energy state. The modified nanodiamonds have essential changes, and it is possible to obtain stable nanodiamond suspensions in non-aqueous media. The modified nanodiamonds have improved dispersibility and are better than those in aqueous solutions.

[0042] The specific steps of step three are: adding lubricating base oil to the nano-diamond suspension obtained in step two for stirring and mixing, and adding 0.1-0.2 parts of nano-diamond suspension to 1000 parts of lubricating oil. The specific steps of step three are: adding 22% fatty acid glyceride and 36% octylphenol polyoxyethylene ether to the mixed solution of lubricating oil and nano-diamond suspension, placing the mixed solution in an ultrasonic container for 20 minutes, and then heating the mixed solution to 80°C for shear stirring to obtain a nano-diamond lubricating oil product. The modified nano-diamond suspension with improved dispersibility is easier to mix in the lubricating base oil, preventing the nano-diamond suspension from precipitating and agglomerating. The fatty acid glyceride in the raw material preparation is almost not hydrolyzed in neutral water and is slightly acidic. This stability enables the fatty acid glyceride to maintain its structural and functional integrity under various environments, and the octylphenol polyoxyethylene ether is also soluble in oil and other organic solvents, and has good emulsification properties.

[0043] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a nano-diamond lubricating oil, comprising a nano-diamond lubricating oil raw material, characterized in that: The nano-diamond lubricating oil raw material comprises nano-diamond particles, fatty acid glyceride, octylphenol polyoxyethylene ether and lubricating base oil, and the nano-diamond lubricating oil raw material comprises 3.2% of nano-diamond particles, 22% of fatty acid glyceride, 36% of octylphenol polyoxyethylene ether and 38.8% of lubricating base oil. The preparation method of the nano-diamond lubricating oil comprises the following steps: Step 1, sorting the nano-diamond particles and modifying the surface of the nano-diamond; Step 2, subjecting the nano-diamond particles modified in step 1 to high-speed crushing; Step three, mixing the nano-diamond powder with fatty acid glyceride, octylphenol polyoxyethylene ether and lubricating base oil by ultrasonic stirring to obtain a nano-diamond lubricating oil product.

2. The method for preparing a nano-diamond lubricating oil according to claim 1, characterized in that: The specific steps of step one are: using double distilled deionized water as a dispersant medium, and utilizing solid phase grafting of a silylation reaction to modify the surface of the nano-diamond particles.

3. The method for preparing a nano-diamond lubricating oil according to claim 2, characterized in that: The specific steps of step one are: reacting trimethylchlorosilane, trimethylsulfoxonium iodide and double distilled deionized water, the reaction ensures the silylation process of hydroxyl group under the participation of water, and the molar ratio of trimethylchlorosilane and trimethylsulfoxonium iodide is 1:

1.

4. The method for preparing a nano-diamond lubricating oil according to claim 3, characterized in that: The specific steps of step 1 are: filling the mixture generated by the silylation reaction into a flask, adding nano-diamond particles in small amounts and multiple times to mix, heating the suspension obtained from the mixture to boiling for 5 hours, cooling and leaving it for 12 hours, fractionating the residue of the silyl mixture from the mixture, heating the remaining solid at 300° C. in a vacuum for 5 hours, and obtaining modified nano-diamond particles.

5. The method for preparing a nano-diamond lubricating oil according to claim 1, characterized in that: The specific steps of step 2 are: preheating the nano-diamond particles obtained in step 1 to 430° C. in a high vacuum environment of 1.33×10-4 Pa for 4 hours and then cooling.

6. The method for preparing a nano-diamond lubricating oil according to claim 5, characterized in that: The specific steps of step 2 are: adding a grinding aid to the cooled nano-diamond particles, and then using a high-speed grinding ball mill to grind them.

7. The method for preparing a nano-diamond lubricating oil according to claim 6, characterized in that: The specific steps of step 2 are: treating the nano-diamond powder obtained by high-speed ball milling at a pressure of about 10-4Pa and a desorption temperature of 35°C for 4 hours, treating it in an ultrasonic ring, and obtaining a stable suspension of nano-diamonds with a size of 18-32nm in an aqueous medium.

8. The method for preparing a nano-diamond lubricating oil according to claim 1, characterized in that: The specific steps of step three are: adding lubricating base oil to the nano-diamond suspension obtained in step two and stirring and mixing, and adding 0.1-0.2 parts of the nano-diamond suspension to 1000 parts of the lubricating oil.

9. The method for preparing a nano-diamond lubricating oil according to claim 8, characterized in that: The specific steps of step three are: adding 22% fatty acid glyceride and 36% octylphenol polyoxyethylene ether to the mixed solution of lubricating oil and nano-diamond suspension, placing the mixed solution in an ultrasonic container for 20 minutes, and then heating the mixed solution to 80° C. for shear stirring to obtain a nano-diamond lubricating oil product.

Images