Method for preparing nano copper powder lubricating oil by direct wet heat reduction in base oil and nano copper powder lubricating oil
The nano-copper powder lubricant is prepared in one step by directly performing a wet heat reduction reaction in the base oil, thereby solving the problems of complex preparation process and waste of resources in the prior art and realizing efficient and low-cost production of nano-copper powder lubricant.
Patent Information
- Application Number
- CN202311139642.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-05
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2043-09-05
AI Technical Summary
The preparation method of nano copper powder lubricating oil in the prior art requires the steps of separation and remixing, which leads to a complicated production process and serious waste of resources.
The nano-copper powder lubricant is prepared directly in one step by wet heat reduction reaction using base oil as solvent. By adding surfactant and copper salt to the base oil and utilizing the co-reduction effect of hydrogen and reducing agent, the nano-copper powder is prepared in situ.
The production process is simplified, resources are saved, costs are reduced, and the dispersibility and stability of nano copper powder in base oil are improved.
Smart Images
Figure CN117165355B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of lubricating oils, and particularly relates to a method for preparing nano-copper powder lubricating oil by direct wet-heat reduction in base oil and the nano-copper powder lubricating oil. Background Art
[0002] Lubricant additives are widely used in lubricants to reduce friction, minimize wear, and even repair worn surfaces. In recent years, conventional lubricant additives have reached their limits, leading to a growing research interest in the field of mechanical lubrication to investigate nanomaterials as lubricant additives to enhance friction and wear resistance. Nano-copper powders, as lubricant additives, exhibit excellent friction reduction, anti-wear, and wear self-repair properties, making them particularly suitable for lubrication under low-speed, heavy-load conditions and suitable for use in advanced lubricants.
[0003] In the prior art, the preparation method of nano copper powder mainly contains vapor deposition method, electrolytic method, wet heat reduction method, mechanical grinding method, arc plasma method etc. Among them, wet heat reduction method has been widely studied because it has the characteristics of simple equipment, low cost and efficient preparation. However, the nano copper powder prepared by wet heat reduction method is dispersed in a solvent and needs to be separated and purified by complex means. Meanwhile, simple nano copper powder cannot be used alone because of its poor stability in base oil, and usually needs to be coordinated with a certain proportion of surfactant to improve its dispersion stability. Therefore, the separated nano copper powder needs to be mixed with base oil with a certain proportion again with a surfactant to obtain nano copper powder lubricating oil. This separation-remixing method has caused the production process route of nano copper powder lubricating oil to be complicated, causing a huge waste of resources. Summary of the Invention
[0004] The purpose of the present invention is to provide a method for preparing nano-copper powder lubricating oil by direct wet heat reduction in base oil and the nano-copper powder lubricating oil, which overcomes the problems of the above-mentioned prior art method for preparing nano-copper powder lubricating oil using a separation-remixing method, resulting in a complex production process route and waste of resources.
[0005] The technical solutions adopted by the present invention to achieve the above-mentioned purpose are as follows.
[0006] The present invention provides a method for preparing nano copper powder lubricating oil by direct wet heat reduction in base oil, comprising the following steps:
[0007] Step 1: first, uniformly dispersing the surfactant in the base oil to prepare a surfactant-oil solution, then adding a reducing agent and a copper salt to the surfactant-oil solution, and mixing them uniformly to obtain a surfactant-copper salt-oil solution;
[0008] Alternatively, the copper salt is first uniformly dispersed in an auxiliary solvent to prepare a copper salt-auxiliary solvent solution, the copper salt-auxiliary solvent solution is then uniformly dispersed in a base oil, and a reducing agent is added and mixed uniformly to obtain a copper salt-auxiliary solvent-oil solution;
[0009] Step 2: Add a surfactant-copper salt-oil solution or a copper salt-auxiliary solvent-oil solution into a reaction device, replace the air with hydrogen, fill with hydrogen, heat to 110-180°C and react for 0.1-12 hours, and separate to obtain nano-copper powder lubricating oil.
[0010] Preferably, in step 1, the surfactant comprises a mixture of one or more of polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB), sodium polyacrylate (PAAS), chitosan, and sodium dodecylbenzenesulfonate in any proportion.
[0011] Preferably, in step 1, the base oil comprises a mixture of one or more of poly-α-olefin (PAO), alkyl naphthalene (AN), synthetic ester, and vegetable oil in any proportion.
[0012] Preferably, in step 1, the copper salt comprises a mixture of one or more of copper chloride, copper acetate, copper rosinate, copper stearate, copper naphthenate, amino acid copper, and quinoline copper in any proportion.
[0013] Preferably, in step 1, the auxiliary solvent comprises a mixture of one or more of cyclohexanone, cyclohexane, and NMP in any proportion.
[0014] Preferably, in step 1, the reducing agent comprises a mixture of one or more of formic acid, formaldehyde, oxalic acid, ethylene glycol, glycerol, ascorbic acid, and hydrazine hydrate in any proportion. More preferably, the reducing agent comprises a mixture of one or more of formic acid, formaldehyde, and oxalic acid in any proportion.
[0015] Preferably, in step 1, the mass percentage of the surfactant in the surfactant-oil solution is 0.5%-5%.
[0016] Preferably, in step 1, the mass percentage of copper element in the surfactant-copper salt-oil solution is 0.1%-1.5%, and the molar ratio of the reducing agent to the copper element is less than or equal to 3:1.
[0017] Preferably, in step 1, the volume ratio of the auxiliary solvent to the base oil is between 1:1 and 1:2.
[0018] Preferably, in step 1, the concentration of the copper salt in the copper salt-auxiliary solvent solution is between 0.1 mol / L and 0.5 mol / L.
[0019] Preferably, in step 1, the molar ratio of the reducing agent to the copper salt in the copper salt-auxiliary solvent-oil solution is between 2:1 and 3:1.
[0020] Preferably, in step 2, the pressure of the hydrogen gas is 0.1 MPa-8 MPa.
[0021] Preferably, in step 2, the reaction equipment is a high-pressure reactor.
[0022] The present invention also provides nano copper powder lubricating oil prepared by the method for preparing nano copper powder lubricating oil by direct wet heat reduction in the above base oil.
[0023] Compared with the prior art, the present invention has the following beneficial effects:
[0024] The method for preparing nano copper powder lubricating oil by direct wet heat reduction in base oil of the present invention uses base oil as solvent and directly adopts wet heat reduction reaction to prepare nano copper powder lubricating oil in one step, which can shorten the production process, save resources and reduce costs.
[0025] The method for preparing nano copper powder lubricating oil by direct wet heat reduction in base oil of the present invention can adjust the ratio of hydrogen and other reducing agents for co-reduction, has a wide adjustment range of reduction behavior, and produces pure and pollution-free products.
[0026] The method for preparing nano-copper powder lubricating oil by direct wet-heat reduction in base oil of the present invention can be extended to various base oils by adapting a surfactant to the base oil, and has good universality.
[0027] The method for preparing nano copper powder lubricating oil by direct wet heat reduction in base oil of the present invention solves the problem that the precursor copper salt is not easily soluble in the base oil by utilizing an auxiliary solvent compatible with the base oil, thereby enhancing the dispersion of the precursor copper ions in the solution.
[0028] The method for preparing nano copper powder lubricating oil by direct wet heat reduction in base oil of the present invention prepares nano copper powder in situ in a working medium. The obtained nano copper powder has uniform size and good stability. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0030] Figure 1 This is the laser particle size result spectrum of the nano copper powder obtained in Example 1 of the present invention;
[0031] Figure 2 This is the X-ray diffraction pattern of the nano copper powder obtained in Example 1 of the present invention;
[0032] Figure 3 This is the laser particle size result spectrum of the nano copper powder obtained in Example 2 of the present invention;
[0033] Figure 4 This is the laser particle size result spectrum of the nano copper powder obtained in Example 3 of the present invention. DETAILED DESCRIPTION
[0034] In order to further understand the present invention, preferred embodiments of the present invention are described below. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.
[0035] The method for preparing nano copper powder lubricating oil by direct wet heat reduction in base oil of the present invention comprises the following steps:
[0036] Step 1: First, a surfactant is uniformly dispersed in a base oil to prepare a surfactant-oil solution, and then a reducing agent is added to the surfactant-oil solution and mixed uniformly, and a copper salt is uniformly dispersed in the surfactant-oil solution. Alternatively, a reducing agent and a copper salt can be added to the surfactant-oil solution and mixed uniformly to obtain a surfactant-copper salt-oil solution;
[0037] Alternatively, the copper salt is first uniformly dispersed in an auxiliary solvent to prepare a copper salt-auxiliary solvent solution, the copper salt-auxiliary solvent solution is then uniformly dispersed in a base oil, and a reducing agent is added and mixed uniformly to obtain a copper salt-auxiliary solvent-oil solution;
[0038] Step 2: Add a surfactant-copper salt-oil solution or a copper salt-auxiliary solvent-oil solution into a reaction device, replace the air with hydrogen, fill with hydrogen, heat to 110-180°C and react for 0.1-12 hours, and separate to obtain nano-copper powder lubricating oil.
[0039] In the above technical solution, the base oil serves as the wet heat reaction solvent and morphology controller, the copper salt serves as the reaction precursor, the auxiliary solvent or surfactant serves as the reaction aid to promote the compatibility of the precursor copper salt with the base oil, and the hydrogen and reducing agent play a co-reduction role.
[0040] In the above technical solution, in step 1, the surfactant preferably includes a mixture of one or more of polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB), sodium polyacrylate (PAAS), chitosan, and sodium dodecylbenzenesulfonate in any proportion.
[0041] In the above technical solution, in step 1, the base oil preferably comprises a mixture of one or more of poly-α-olefin (PAO), alkyl naphthalene (AN), synthetic ester, and vegetable oil in any proportion. The vegetable oil is not particularly limited, and may be peanut oil, for example.
[0042] In the above technical solution, in step 1, the copper salt preferably includes a mixture of one or more of copper chloride, copper acetate, copper rosinate, copper stearate, copper naphthenate, amino acid copper, and quinoline copper in any proportion.
[0043] In the above technical solution, in step 1, the auxiliary solvent preferably includes a mixture of one or more of cyclohexanone, cyclohexane, and NMP in any proportion.
[0044] In the above technical solution, in step 1, the reducing agent preferably includes a mixture of one or more of formic acid, formaldehyde, oxalic acid, ethylene glycol, glycerol, ascorbic acid, and hydrazine hydrate in any proportion. More preferably, the reducing agent includes a mixture of one or more of formic acid, formaldehyde, and oxalic acid in any proportion. This type of reducing agent generates gaseous products and water after oxidation.
[0045] In the above technical solution, in step 1, the mass percentage of the surfactant in the surfactant-oil solution is preferably 0.5%-5%; more preferably 2%-4%.
[0046] In the above technical solution, in step 1, the mass percentage of copper element in the surfactant-copper salt-oil solution is preferably 0.1%-1.5%, more preferably 0.5%; the molar ratio of the reducing agent to the copper element is preferably less than or equal to 3:1, more preferably 0.2-2:1.
[0047] In the above technical solution, in step 1, the uniform dispersion and mixing methods are preferably magnetic stirring, and the rotation speed is not particularly limited and can be 700 rpm.
[0048] In the above technical solution, in step 1, the volume ratio of the auxiliary solvent to the base oil is between 1:1 and 1:2; the concentration of the copper salt in the copper salt-auxiliary solvent solution is between 0.1 mol / L and 0.5 mol / L; and the molar ratio of the reducing agent to the copper salt in the copper salt-auxiliary solvent-oil solution is between 2:1 and 3:1.
[0049] In the above technical solution, in step 2, the pressure of the hydrogen gas charged is preferably 0.1 MPa-8 MPa.
[0050] In the above technical solution, in step 2, the reaction equipment is preferably a reactor, usually a high-pressure reactor.
[0051] In the above technical solution, in step 2, the temperature is preferably raised to 130-150° C. and the reaction is carried out for 1 hour.
[0052] The nano copper powder lubricating oil prepared by the method for preparing nano copper powder lubricating oil by direct wet heat reduction in base oil of the present invention has nano copper powder with uniform size and good stability, and the average particle size can be 36.2nm-67.1nm.
[0053] The terms used in the present invention generally have the meanings commonly understood by those skilled in the art, unless otherwise specified.
[0054] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the embodiments.
[0055] In the following examples, various processes and methods not described in detail are conventional methods known in the art. Unless otherwise specified, the materials, reagents, devices, instruments, equipment, etc. used in the following examples can be obtained from commercial sources.
[0056] Example 1
[0057] Disperse 0.5g of copper acetate evenly in 25ml of cyclohexanone to create a 0.1mol / L auxiliary solvent-copper salt solution. Add 25ml of PAO10 and stir to mix thoroughly. Add 1.216g of ascorbic acid and stir to mix thoroughly to create a copper salt-cyclohexanone-oil solution. Place the copper salt-cyclohexanone-oil solution in a reactor, purge it five times with hydrogen, then fill it with 1.5MPa of hydrogen. Heat to 130°C and allow to react for 1h. Cool to obtain the nano-copper powder lubricant.
[0058] The nano copper powder lubricant prepared in Example 1 was subjected to laser particle size test and X-ray diffraction pattern test. The laser particle size test results of the nano copper powder are as follows: Figure 1 As shown, from Figure 1 It can be seen that the average particle size of the nano copper powder is 56.3nm. The X-ray diffraction pattern (XRD) of the nano copper powder is as follows Figure 2 As shown, from Figure 2 It can be seen that the nano copper powder is composed of single-phase face-centered cubic copper.
[0059] Example 2
[0060] CTAB was evenly dispersed in peanut oil to prepare a CTAB-oil solution with a 4% CTAB mass fraction. Formic acid and copper stearate were added and stirred thoroughly to create a CTAB-copper salt-oil solution with a copper mass fraction of 0.5% (relative to the peanut oil). The molar ratio of formic acid to copper was 2:1. The CTAB-copper salt-oil solution was placed in a reactor, washed with hydrogen five times, then filled with 0.2 MPa of hydrogen. The reactor was heated to 150°C and reacted for 1 hour. After cooling, the nano-copper powder lubricant was obtained.
[0061] The nano copper powder lubricant prepared in Example 2 was subjected to laser particle size test. The laser particle size test results of the nano copper powder are as follows: Figure 3 As shown, from Figure 3 It can be seen that the average particle size of the nano copper powder is 67.1 nm.
[0062] Example 3
[0063] PAAS was evenly dispersed in Esterex A32 synthetic ester to prepare a PAAS / oil solution with a 2% PAAS mass fraction. Ethylene glycol and copper acetate were added and stirred thoroughly to create a PAAS-copper salt-oil solution with a copper mass fraction of 0.5% (relative to the synthetic ester). The molar ratio of ethylene glycol to copper was 0.2:1. The PAAS-copper salt-oil solution was placed in a reactor, washed with hydrogen five times, then filled with 5 MPa of hydrogen. The reaction was heated to 110°C and allowed to react for 4 hours. After cooling, the nano-copper powder lubricant was obtained.
[0064] The nano copper powder lubricant prepared in Example 3 was subjected to laser particle size test. The laser particle size test results of the nano copper powder are as follows: Figure 4 As shown, from Figure 4 It can be seen that the average particle size of the nano copper powder is 36.2 nm.
[0065] Comparative Example 1
[0066] Add 0.5g of copper acetate to 50ml of PAO10 and stir to mix thoroughly. Copper acetate is insoluble in PAO10, and the mixture forms a blue suspension under stirring. Place the suspension in an autoclave, purge it with hydrogen five times, then fill it with 1.5MPa of hydrogen. Heat to 130°C and allow to react for 1h. After cooling, open the autoclave lid and remove the quartz liner. Black particles are found at the bottom, indicating a failed preparation.
[0067] It should be noted and understood that various modifications and improvements can be made to the invention described in detail above without departing from the spirit and scope of the invention as claimed. Therefore, the scope of the technical solution claimed is not limited by any specific exemplary teaching given.
[0068] The applicant states that the present invention is intended to illustrate the detailed methods of the present invention through the above-described embodiments, but the present invention is not limited to the above-described detailed methods, that is, it does not mean that the present invention must rely on the above-described detailed methods in order to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for various raw materials in the products of the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., are all within the scope of protection and disclosure of the present invention.
Claims
1. A method for preparing nano copper powder lubricating oil by direct wet heat reduction in base oil, characterized in that: Here are the steps: Step 1: First, a surfactant is uniformly dispersed in a base oil to prepare a surfactant-oil solution, and then a reducing agent and a copper salt are sequentially added to the surfactant-oil solution and mixed to obtain a surfactant-copper salt-oil solution; Alternatively, the copper salt is first uniformly dispersed in an auxiliary solvent to prepare a copper salt-auxiliary solvent solution, the copper salt-auxiliary solvent solution is then uniformly dispersed in a base oil, and a reducing agent is added and mixed uniformly to obtain a copper salt-auxiliary solvent-oil solution; Step 2: Add a surfactant-copper salt-oil solution or a copper salt-auxiliary solvent-oil solution into a reaction device, replace the air with hydrogen, fill with hydrogen, heat to 110-180°C, react for 0.1-12 hours, and separate to obtain nano-copper powder lubricating oil; Wherein, in step 1, the base oil comprises a mixture of one or more of poly-α-olefin, alkyl naphthalene, synthetic ester, and vegetable oil in any proportion; the reducing agent comprises a mixture of one or more of formic acid, formaldehyde, oxalic acid, ethylene glycol, glycerol, ascorbic acid, and hydrazine hydrate in any proportion; the auxiliary solvent comprises a mixture of one or more of cyclohexanone, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, and dimethylformamide in any proportion; Wherein, in step 2, the pressure of the hydrogen gas charged is 0.1MPa-6MPa.
2. The method for preparing nano copper powder lubricating oil by direct wet heat reduction in a base oil according to claim 1, characterized in that: In step 1, the surfactant includes one or more of polyvinyl pyrrolidone, cetyltrimethylammonium bromide, sodium polyacrylate, chitosan, and sodium dodecylbenzenesulfonate mixed in any proportion.
3. The method for preparing nano copper powder lubricating oil by direct wet heat reduction in a base oil according to claim 1, characterized in that: In step 1, the copper salt includes one or more of copper chloride, copper acetate, copper rosinate, copper stearate, copper naphthenate, amino acid copper, and quinoline copper, mixed in any proportion.
4. The method for preparing nano copper powder lubricating oil by direct wet heat reduction in a base oil according to claim 1, characterized in that: In step one, The mass percentage of the surfactant in the surfactant-oil solution is 0.5%-5%; The mass percentage of the copper element in the surfactant-copper salt-oil solution is 0.1%-1.5%, and the molar ratio of the reducing agent to the copper element is less than or equal to 3:
1.
5. The method for preparing nano copper powder lubricating oil by direct wet heat reduction in a base oil according to claim 1, characterized in that: In step one, The volume ratio of the auxiliary solvent to the base oil is between 1:1 and 1:2; The copper salt concentration in the copper salt-auxiliary solvent solution is between 0.1 mol / L and 0.5 mol / L; The molar ratio of the reducing agent to the copper salt in the copper salt-auxiliary solvent-oil solution is between 2:1 and 3:
1.
6. Nano-copper powder lubricating oil prepared by the method for preparing nano-copper powder lubricating oil by direct wet-heat reduction in a base oil as claimed in any one of claims 1 to 5.