CN112296345B

CN112296345B - Preparation method of self-dispersible nano-copper with long organic carbon chain, nano-copper preparation and application thereof

Info

Publication number: CN112296345B
Application number: CN201910666577.9A
Authority: CN
Inventors: 赵阳; 石舟舟; 刘广宇; 范文智; 范成力
Original assignee: Francool Technology Shenzhen Co ltd
Current assignee: Francool Technology Shenzhen Co ltd
Priority date: 2019-07-23
Filing date: 2019-07-23
Publication date: 2022-02-18
Anticipated expiration: 2039-07-23
Also published as: CN112296345A; WO2021012754A1

Abstract

The invention provides a preparation method of self-dispersible nano-copper with a long organic carbon chain, which comprises the following steps: 1) putting a copper source water solution containing divalent copper ions in a nitrogen, argon or air atmosphere, and heating to 40-75 ℃; 2) adding a reducing agent into the reaction system in the step 1) to obtain a reduced copper source solution; 3) mixing the HDDP coating agent and an organic solvent at a final concentration of 0.1mol/L to 0.9mol/L to prepare a coating agent solution; 4) adding the coating agent solution obtained in the step 3) into the reduced copper source solution obtained in the step 2) for reaction; 5) obtaining a nano copper product; wherein the molar ratio of the copper source to the reducing agent is 1: 20-20: 1; the molar ratio of the copper source to the HDDP coating agent is 1: 5-5: 1. The invention realizes the synthesis of the nano copper preparation with stable self-dispersion of an oily and emulsion system.

Description

Preparation method of self-dispersible nano-copper with long organic carbon chain, nano-copper preparation and application thereof

Technical Field

The invention belongs to the technical field of nano copper materials, and particularly relates to a preparation method of self-dispersible nano copper with a long organic carbon chain, a nano copper preparation and application thereof.

Background

The metal nanoparticles refer to metal particles with the components reduced to a nanometer degree (5-100 nm) in shape, and the chemical bonding structure of the novel nano material is different from that of metal particles with the same chemical components. Since 6nm iron nanoparticles were first prepared in 1984 by Gleiter H in germany, the research on nano-metals in the world is vigorously carried out and made a great progress. The research on the nano copper material is started early, and the nano copper material can be used as a catalyst, for preparing superplastic steel, for preparing a gas sensor, as a solid lubricant and the like.

So far, the preparation of nano-copper is mainly limited to solid nano-copper powder, and a preparation method of nano-copper paste capable of realizing self-dispersion of an oily system and an aqueous system is rarely reported. Since the nano copper powder (10-100 nm) has the characteristics of small size, large specific surface area, small resistance, quantum size effect, macroscopic quantum tunneling effect and the like, and has some new characteristics different from those of conventional materials, research on preparation, performance and application of the nano copper powder has been widely concerned at home and abroad in recent years.

Nano-copper powders have many applications including: 1. the nano copper powder is used for solid lubricant, and can form a stable suspension by being dispersed in various lubricating oils in a proper mode, each liter of the oil contains millions of superfine metal powder particles which are combined with the surface of the solid to form a smooth protective layer and simultaneously fill micro scratches, so that the friction and the abrasion are greatly reduced, and the effect is more remarkable especially under the conditions of heavy load, low speed and high temperature vibration; 2. the nanometer copper powder is used for conductive materials, has high conductivity and can be used for manufacturing conductive paste (conductive adhesive, magnetic conductive adhesive and the like), the conductive paste is widely used for manufacturing conductive cloth, conductive sealing tape, connecting adhesive of the conductive materials and the like in the industry, and the nanometer copper powder plays an important role in the miniaturization of microelectronic devices; 3. the nano copper powder is used for manufacturing a nano copper material, the nano copper with high density and high purity is synthesized by adopting a new process, the grain size is only 30nm, which is one dozen of ten-thousandth of that of the conventional copper, the further cold rolling experiment shows that the super plastic ductility of the nano copper at room temperature can be achieved, the nano copper can deform for more than 50 times at room temperature without cracks, and a relevant paper is published in the journal of Science 25.2.25.2.2000; P.G Sanders et al obtain the tensile mechanical property of nano copper material (grain size 10-110 nm), find that the yield strength is 10 times (300 MPa) of common annealed copper (grain size 20 μm), the elongation can reach more than 8%; the method shows that the strength and the plasticity of the copper after the nanocrystallization are obviously improved, and the method has important value on fine processing and micromachine manufacturing of materials. Besides the application, the nano copper powder also has higher application value in the fields of modified phenolic resin, medicine price adjusting materials for treating osteoporosis, hyperosteogeny and the like, aviation and the like.

For the application of nano-copper powder in the field of lubrication, there is still a problem that it is greatly limited due to its poor dispersibility. At present, the common method for preparing the nano-copper powder lubricating oil additive is to prepare the nano-copper powder firstly and then add the nano-copper powder into the lubricating oil, but when nano-copper particles are added into the lubricating oil, the nano-copper particles have large tendency of automatic aggregation due to small granularity and high surface energy, and the particles are easily aggregated, and even if the aggregation is dispersed in the lubricating oil by force, the particles are aggregated again when colliding with each other, so that the aggregation is generated. Once agglomerated, precipitated or denatured, the particles no longer possess the original characteristics and may also negatively impact mechanical systems designed based on oil lubrication. The problem of compatibility between the nano copper powder and the lubricating oil is solved by adding a large amount of auxiliary agents such as surfactants, coupling agents and the like, and the nano copper powder is easy to oxidize and difficult to store before being added into the lubricating oil, so that industrialization is difficult to realize.

At present, self-dispersible nano-copper systems exist in the prior art, but still have remarkable defects, such as pungent odor, poor oxidation resistance stability, easy color change, easy sedimentation, difficult dispersion, poor acid and alkali resistance and poor anion and cation resistance. These drawbacks are essentially due to the following design considerations: the effective coordination end of the coating agent is less, the steric hindrance of the coating agent is less, the stability of the coating agent is poor, and the like. The main technical difficulty is therefore focused on the design of the capping agent molecule.

The molecules commonly applied to the coating agent at present are mainly divided into four main categories: the first is dialkyl dithiophosphoric acid (HDDP) and derivatives thereof; the second is Dithiocarbalkoxy (DTC) and its derivatives; the third kind is thioglycolic acid and derivatives thereof, including natural amino acids such as cysteine; the fourth class is non-thio molecules, including oleylamine, oleic acid, PVP, and derivatives. The common characteristic of the three is that the three have organic sulfur functional groups which can coordinate with the surface of the nano copper.

The main differences between these four classes of coating agents are: the first class of coating agent HDDP and the second class of coating agent DTC are dithio chelating systems, the third class of coating agent thioglycolic acid is a monothio coordination system, the third class of coordination capability is weaker, and formed nano copper particles are easy to agglomerate and oxidize until sedimentation; second, the first cladding agent HDDP also comprises a phosphorus atom besides two sulfur atoms, while the second cladding agent DTC does not comprise the phosphorus atom, and the second cladding agent is inferior to the first cladding agent in the wear-resistant and pressure-resistant performance; the third and fourth coating agents form a nano copper system which is more unstable due to the loss of sulfur atoms, and are extremely difficult to generate small-particle-size particles or extremely easy to settle.

Among them, the lubricating, anti-wear, pressure-resistant and anti-oxidation properties of the first type of coating agent HDDP have attracted attention for a long time. However, HDDP itself has an offensive odor and cannot be used directly, and the most important application of HDDP is to prepare zinc dialkyldithiophosphate (ZDDP). Of these, the alkyl groups in ZDDP are typically derived from short chain alcohols. ZDDP also has a certain pungent odor, which limits its application in metal processing. In addition to the disappearance of odor, nano-copper produced by HDDP, compared to ZDDP, enhanced lubricating activity and antibacterial properties due to the presence of copper.

In the prior art, the document reports that HDDP is used for preparing self-dispersed nano-copper. However, the existing report is limited to the use of short carbon chain HDDP (carbon number is less than or equal to 8), and does not take the consideration of oxidation resistance, wear resistance and rust resistance in the field of metal processing, the reported nano copper has the defects of easy discoloration, difficult storage, deep color, large viscosity and low copper concentration, and the adopted preparation process is not beneficial to large-scale production because of the involvement of a strong carcinogen benzene, so that the actual industrial application cannot be carried out.

These early studies of nano-copper are still far from industrial application and commercialization, and further deepening is needed in the theoretical aspect and further improvement is needed in the application aspect.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to provide a preparation method of the self-dispersible nano copper with the long organic carbon chain, combine the requirements of the preparation method of the lubricating, wear-resistant, pressure-resistant, anti-rust and antioxidant antibacterial additive in the field of metal processing, and realize the synthesis of the nano copper agent with stable self-dispersible oily and emulsion systems.

The invention provides a preparation method of self-dispersible nano-copper with a long organic carbon chain, which comprises the following steps:

1) putting a copper source water solution containing divalent copper ions in a nitrogen, argon or air atmosphere, and heating to 40-75 ℃;

2) adding a reducing agent into the reaction system in the step 1) to obtain a reduced copper source solution;

3) mixing an HDDP coating agent with an organic solvent to prepare a coating agent solution, wherein the final concentration of the mixed solution is 0.1mol/L to 0.9 mol/L;

4) adding the coating agent solution obtained in the step 3) into the reduced copper source solution obtained in the step 2) for reaction;

5) obtaining a nano copper product;

wherein the molar ratio of the copper source to the reducing agent is 1: 20-20: 1;

the molar ratio of the copper source to the HDDP coating agent is 1: 5-5: 1.

Preferably, the copper source aqueous solution in step 1) is selected from any one or more of copper sulfate pentahydrate, copper chloride, copper bromide, copper acetate, copper nitrate and copper acetylacetonate aqueous solution.

Preferably, the reducing agent of step 2) is selected from hydrazine hydrate and sodium hypophosphite (NaH)₂PO₂) Any one or more of sodium borohydride, ascorbic acid (vitamin C) and sodium ascorbate.

Preferably, the organic solvent in step 3) is selected from any one or more of petroleum ether, dichloromethane, trichloromethane, pentane, ethyl acetate, diethyl ether, carbon tetrachloride, benzene, toluene, xylene and base oil.

Preferably, the petroleum ether is 60-90 ℃ fraction petroleum ether.

Preferably, the nano-copper mixture is subjected to liquid separation treatment, and a lower water phase is removed to obtain an upper oil phase; centrifuging the oil phase to obtain supernatant; and concentrating the supernatant to obtain the nano copper paste.

Preferably, the collected supernatant is treated to remove the organic solvent.

Preferably, the organic solvent is removed by rotary distillation, reduced pressure distillation or atmospheric distillation.

Preferably, the HDDP capping agent is prepared by: the catalyst is prepared by reacting a carbon-based alcohol compound and phosphorus pentasulfide, wherein the molar ratio of the carbon-based alcohol compound to the phosphorus pentasulfide is 2: 1-8: 1.

Preferably, the carbon-based alcohol compound is at least one of saturated fatty alcohols.

Preferably, the carbon-based alcohol is at least one of a dodecanol, an isooctanol, or an n-dodecyl alcohol.

Preferably, the carbon-based alcohol compound is a mixture of dodecacarbon isomeric alcohol and ethanol, and the molar ratio of the dodecacarbon isomeric alcohol to the ethanol is 5: 1-4: 1.

The invention also provides a nano copper preparation with a long organic carbon chain capable of self-dispersing, and the nano copper preparation is prepared by any one of the methods.

Preferably, the particle size of the prepared nano copper is 10-50 nm, and the mass ratio of pure copper in the nano copper preparation is 20-25%.

The invention also provides application of the nano copper preparation in preparation of a coating additive, an engine oil additive and an oil film bearing oil additive.

According to the preparation method of the self-dispersible nano copper with the long organic carbon chain, provided by the invention, the nano copper prepared by the coating agent has excellent oxidation resistance and metal rust resistance because of containing the organic thiophosphate. The method of the invention closely combines the actual requirements of the metal processing field for lubricating, wear-resistant, pressure-resistant, rust-proof, antioxidant and antibacterial additives, and fully perfects and develops the production process of the HDDP system self-dispersed nano-copper through a large number of experiments and researches; through redesigning the molecules of the coating agent and screening and optimizing the organic solvent in the nano-copper synthesis process, the best preparation process of the self-dispersion nano-copper at present is developed. According to the method, a large amount of coating agents are introduced in the preparation process of the nano copper, the nano copper is combined with the coating agents to generate stable nano copper clusters after being formed, and the clusters mainly show the physical properties of molecules of the coating agents instead of the physical properties of naked nano copper powder due to the fact that the mass main body of the clusters is the coating agents. The nano copper preparation prepared by the method is a nano copper paste capable of realizing self dispersion of an oily and emulsion system, and the formed nano copper has uniform particle size distribution, long-term stability, good transparency and higher copper content. The multifunctional metal processing additive can be widely applied to a plurality of fields and has extremely wide application prospect.

Drawings

In order that the present disclosure may be more readily and clearly understood, reference will now be made in detail to the present disclosure, examples of which are illustrated in the accompanying drawings.

Fig. 1 is a schematic flow chart of a preparation method of the self-dispersible nano-copper with a long organic carbon chain according to the invention.

Detailed Description

In order to explain the technical content, the objects and the effects of the present invention in detail, the following description will be given with reference to the embodiments.

The reagents used in the present specification are all commercially available products, wherein the hydrazine hydrate is commercially available 80% hydrazine hydrate.

As shown in fig. 1, in the method for preparing self-dispersible nano-copper with a long organic carbon chain according to the present invention, before step 1, an HDDP capping agent is prepared: reacting the carbon-based alcohol compound with phosphorus pentasulfide to obtain the dialkyl dithiophosphate coating agent. In this embodiment, the molar ratio of the carbon-based alcohol compound to the phosphorus pentasulfide can be selected according to actual needs, and preferably, the molar ratio of the carbon-based alcohol compound to the phosphorus pentasulfide is 2:1 to 8: 1. The carbon-based alcohol compound can be aliphatic alcohol and aromatic alcohol, preferably the carbon-based alcohol compound is at least one of saturated aliphatic alcohol, such as one or more of ethanol, isopropanol, isooctanol, decanol, n-dodecyl alcohol and dodecyl isomeric alcohol.

Step 1: mixing a copper source with water to obtain a copper source solution, placing the copper source solution in a nitrogen, argon or air atmosphere, heating to 40-75 ℃, preferably 50-65 ℃, and further preferably 55 ℃; the copper source water solution is selected from one or more of copper sulfate pentahydrate, copper chloride, copper bromide, copper acetate, copper nitrate and copper acetylacetonate water solution.

Step 2: adding a reducing agent into the copper source solution heated in the step 1 for reaction to obtain a reduced copper source solution; the reducing agent is selected from hydrazine hydrate and sodium hypophosphite (NaH)₂PO₂) Any one or more of sodium borohydride, ascorbic acid (vitamin C) and sodium ascorbate.

And step 3: mixing the dialkyl dithiophosphate coating agent with an organic solvent to obtain a coating agent solution; the organic solvent is selected from one or more of petroleum ether 60-90, dichloromethane, chloroform, pentane, ethyl acetate, diethyl ether, carbon tetrachloride, benzene, toluene, xylene and base oil.

And 4, step 4: and adding the coating agent solution into the reduced copper source solution for reaction to obtain a nano copper mixture.

The molar ratio of the copper source to the dialkyl dithiophosphoric acid coating agent can be adjusted according to specific needs, and preferably is 1: 5-5: 1. Preferably, the molar ratio of the copper source to the reducing agent is 1:20 to 20: 1.

The preparation method can further comprise the following steps: carrying out liquid separation treatment on the nano copper mixture, and removing the water phase on the lower layer to obtain an oil phase on the upper layer; centrifuging the oil phase to obtain supernatant; and concentrating the supernatant to obtain the nano copper paste.

The particle size of the nano-copper obtained by the invention is 10-50 nm measured by a nano-particle size detector; the mass ratio of pure copper in the nano copper preparation is 20-25% by thermogravimetric analyzer determination.

Example 1

The embodiment is a preparation method of nano-copper capable of self-dispersion, which comprises the following steps:

the specific preparation process of the HDDP coating agent is as follows:

adding a carbon-based alcohol compound and phosphorus pentasulfide into a 250mL single-neck flask, plugging a bottle stopper of the single-neck flask, connecting a gas guide pipe, heating the reaction mixture to 80 ℃ under the stirring condition, preserving the temperature for 3 hours, and introducing hydrogen sulfide gas released by the reaction into a copper sulfate aqueous solution through the gas guide pipe. And removing the residual solid in the reaction system after the reaction is finished to obtain transparent light yellow liquid, namely the dialkyl dithiophosphate coating agent. In this embodiment, the hydrogen sulfide gas generated by the reaction may be absorbed by an alkaline system such as an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous calcium hydroxide solution, or an emulsion. The hydrogen sulfide gas can also be converted into sulfur dioxide by combustion or oxidation and then absorbed separately.

Step 1: adding a copper source and water into a 500mL beaker to fully dissolve the copper source in the water to obtain a copper source solution, pouring the copper source solution into a reaction kettle, and then closing the reaction kettle; introducing nitrogen into the reaction kettle, and heating the reaction system to 55 ℃;

step 2: adding a reducing agent into the reaction kettle, and reacting for 10min under the stirring condition;

and step 3: mixing a dialkyl dithiophosphate coating agent with an organic solvent to obtain a coating agent solution, wherein the final concentration of the dialkyl dithiophosphate coating agent is 0.1 mol/L-0.9 mol/L;

and 4, step 4: adding the coating agent solution into a reaction kettle, reacting for 2 hours, and stopping stirring and heating;

and 5: obtaining the nano copper mixture.

Still further comprising step 6: pouring the nano-copper mixture out of the reaction kettle, separating the mixture by using a separating funnel, and removing the lower water phase to obtain an upper oil phase; centrifuging the obtained oil phase, and removing larger copper powder particles to obtain supernatant; and (4) carrying out rotary evaporation on the supernatant liquid, and removing the solvent to obtain the nano copper paste. When the supernatant is purified, the purification can be carried out by adopting a reduced pressure distillation mode or an atmospheric pressure distillation mode.

Example 2

This example is a preparation method of self-dispersible nano-copper, and is different from example 1 in that:

in step 1, the carbon-based alcohol compound is a mixture composed of 65 mol% n-dodecyl alcohol, 20 mol% isooctanol and 15 mol% ethanol, the total mass is 53.9g (350mmol), the usage amount of phosphorus pentasulfide is 22.2g (100mmol), the molar ratio of mixed alcohol and phosphorus pentasulfide is 3.5:1, and the dialkyl dithiophosphate mixture is finally obtained in step 1.

In step 2, the copper source is copper sulfate pentahydrate with the dosage of 37.4g (150mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate with the dosage of 120mL (about 2mol), the dosage of the dialkyl dithiophosphate mixture is 48g (120mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 3: 40; the mol ratio of the copper sulfate pentahydrate to the dialkyl dithiophosphoric acid is 5:4, the organic solvent is 60-90 parts of petroleum ether, and the dosage is 250 mL.

The chemical reaction equation is as follows:

r is n-dodecyl, ethyl, isooctyl

Example 3

in step 1, the carbon-based alcohol compound is isooctanol with the dosage of 45.5g (350mmol), the dosage of phosphorus pentasulfide is 22.2g (100mmol), the molar ratio of isooctanol to phosphorus pentasulfide is 3.5:1, and the bis (2-ethylhexyl) dithiophosphate is finally obtained in step 1.

In step 2, the copper source is copper sulfate pentahydrate, the dosage is 37.4g (150mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate, the dosage is 120mL (about 2mol), the dosage of the di (2-ethylhexyl) dithiophosphoric acid is 42.5g (120mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 3: 40; the mol ratio of the copper sulfate pentahydrate to the di (2-ethylhexyl) dithiophosphoric acid is 5:4, the organic solvent is 60-90 parts by volume of petroleum ether, and the dosage is 250 mL.

The chemical reaction equation is as follows:

example 4

in step 1, the carbon-based alcohol compound is n-dodecyl alcohol with the dosage of 65.1g (350mmol), the dosage of phosphorus pentasulfide is 22.2g (100mmol), the molar ratio of isooctyl alcohol to phosphorus pentasulfide is 3.5:1, and the di (n-dodecyl) dithiophosphoric acid is finally obtained in step 1.

In the step 2, the copper source is copper sulfate pentahydrate, the dosage is 37.4g (150mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate, the dosage is 120mL (about 2mol), the dosage of the di (n-dodecyl) dithiophosphoric acid is 56g (120mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 3: 40; the mol ratio of the copper sulfate pentahydrate to the di (n-dodecyl) dithiophosphoric acid is 5:4, the organic solvent is 60-90 parts by weight of petroleum ether, and the dosage is 250 mL.

The chemical reaction equation is as follows:

example 5

in step 1, the carbon-based alcohol compounds are n-dodecyl alcohol (54.4g, 280mmol) and ethanol (3.3g, 70mmol), the using amount of phosphorus pentasulfide is 22.2g (100mmol), the molar ratio of mixed alcohol to phosphorus pentasulfide is 3.5:1, and a dialkyl dithiophosphate mixture is finally obtained in step 1.

In step 2, the copper source is copper sulfate pentahydrate in an amount of 37.4g (150mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate in an amount of 120mL (about 2mol), the mixture of dialkyl dithiophosphates is 48g (about 120mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 3: 40; the mol ratio of the copper sulfate pentahydrate to the dialkyl dithiophosphoric acid mixture is 5:4, the organic solvent is 60-90 parts by weight of petroleum ether, and the dosage is 250 mL.

The chemical reaction equation is as follows:

r is n-dodecyl

Example 6

The embodiment of the invention is a preparation method of self-dispersible nano copper, and is different from the embodiment 1 in that:

In step 2, the copper source is copper sulfate pentahydrate with the dosage of 37.4g (150mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate with the dosage of 120mL (about 2mol), the dosage of the dialkyl dithiophosphate mixture is 48g (120mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 3: 40; the mol ratio of the copper sulfate pentahydrate to the dialkyl dithiophosphoric acid mixture is 5:4, the organic solvent is toluene, and the dosage is 250 mL.

The chemical reaction equation is as follows:

r is n-dodecyl, ethyl, isooctyl

Example 7

in the step 1, the carbon-based alcohol compound is a mixture composed of 65 mol% of n-dodecyl alcohol, 20 mol% of isooctanol and 15 mol% of ethanol, the total mass is 53.9g (350mmol), the using amount of phosphorus pentasulfide is 22.2g (100mmol), the molar ratio of the mixed alcohol to the phosphorus pentasulfide is 3.5:1, and the dialkyl dithiophosphate mixture is finally obtained in the step 1.

In step 2, the copper source is copper sulfate pentahydrate with the dosage of 37.4g (150mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate with the dosage of 120mL (about 2mol), the dosage of the dialkyl dithiophosphate mixture is 48g (120mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 3: 40; the molar ratio of copper sulfate pentahydrate to the mixture of dialkyl dithiophosphoric acids is 5:4, and the organic solvent is base oil (100SN) and the amount is 250 mL.

The chemical reaction equation is as follows:

r is n-dodecyl, ethyl, isooctyl

Example 8

In the step 2, the copper source is copper sulfate pentahydrate, the dosage is 56.1g (225mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate, the dosage is 120mL (about 2mol), the dosage of the dialkyl dithiophosphoric acid is 48g (120mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 9: 80; the mol ratio of the copper sulfate pentahydrate to the dialkyl dithiophosphoric acid mixture is 15:8, the organic solvent is 60-90 parts by weight of petroleum ether, and the dosage is 250 mL.

The chemical reaction equation is as follows:

r is n-dodecyl, ethyl, isooctyl

Example 9

in step 1, the carbon-based alcohol compound is a mixture composed of 65 mol% n-dodecyl alcohol, 20 mol% isooctanol and 15 mol% ethanol, the total mass is 30.8g (200mmol), the usage amount of phosphorus pentasulfide is 22.2g (100mmol), the molar ratio of the alkyl alcohol mixture to the phosphorus pentasulfide is 2:1, and the dialkyl dithiophosphate mixture is finally obtained in step 1.

In the step 2, the copper source is copper sulfate pentahydrate, the dosage is 25g (100mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate, the dosage is 120mL (about 2mol), the dosage of the dialkyl dithiophosphate mixture is 200g (500mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 1: 20; the mol ratio of the copper sulfate pentahydrate to the dialkyl dithiophosphoric acid mixture is 1:5, the organic solvent is 60-90 parts by weight of petroleum ether, and the dosage is 250 mL.

The chemical reaction equation is as follows:

r is n-dodecyl, ethyl, isooctyl

Example 10

in step 1, the carbon-based alcohol compound is a mixture composed of 65 mol% n-dodecyl alcohol, 20 mol% isooctanol and 15 mol% ethanol, the total mass is 123.2g (800mmol), the usage amount of phosphorus pentasulfide is 22.2g (100mmol), the molar ratio of mixed alcohol and phosphorus pentasulfide is 8:1, and the dialkyl dithiophosphate mixture is finally obtained in step 1.

In step 2, the copper source is copper sulfate pentahydrate, the dosage is 125g (500mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate, the dosage is 1.5mL (about 25mmol), the dosage of the dialkyl dithiophosphate mixture is 40g (100mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 20: 1; the mol ratio of the copper sulfate pentahydrate to the dialkyl dithiophosphoric acid mixture is 5:1, the organic solvent is 60-90 parts by weight of petroleum ether, and the dosage is 250 mL.

The chemical reaction equation is as follows:

r is n-dodecyl, ethyl, isooctyl

Example 11

In step 2, the copper source is copper sulfate pentahydrate in an amount of 37.4g (150mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, and the reducing agent is 60mL of hydrazine hydrate (about 1mol) and sodium hypophosphite NaH₂PO₂(88g, 1mol), the amount of the dialkyl dithiophosphoric acid mixture is 48g (120mmol), and the molar ratio of copper sulfate pentahydrate to the reducing agent is 3: 40;the mol ratio of the copper sulfate pentahydrate to the dialkyl dithiophosphoric acid is 5:4, the organic solvent is 60-90 parts of petroleum ether, and the dosage is 250 mL.

The chemical reaction equation is as follows:

r is n-dodecyl, ethyl, isooctyl

Example 12

In step 2, the copper source is a mixture of copper sulfate pentahydrate and copper acetate monohydrate in an amount of 15g of copper acetate monohydrate (75mmol) and 18.7g of copper sulfate pentahydrate (75mmol), the water for dissolving copper salt is 200mL, the reducing agent is 80% hydrazine hydrate in an amount of 120mL (about 2mol), the mixture of dialkyl dithiophosphoric acid is 48g (120mmol), and the molar ratio of copper sulfate pentahydrate to the reducing agent is 3: 40; the mol ratio of the copper sulfate pentahydrate to the dialkyl dithiophosphoric acid is 5:4, the organic solvent is 60-90 parts of petroleum ether, and the dosage is 250 mL.

The chemical reaction equation is as follows:

r is n-dodecyl, ethyl, isooctyl

Example 13

In step 2, the copper source is copper sulfate pentahydrate with the dosage of 37.4g (150mmol), the water for dissolving the copper sulfate pentahydrate is 200mL, the reducing agent is 80% hydrazine hydrate with the dosage of 120mL (about 2mol), the dosage of the dialkyl dithiophosphate mixture is 48g (120mmol), and the molar ratio of the copper sulfate pentahydrate to the reducing agent is 3: 40; the mol ratio of the copper sulfate pentahydrate to the dialkyl dithiophosphoric acid is 5:4, the organic solvent is a mixture of 60-90 parts of petroleum ether and 100 parts of toluene, and the dosage of the mixture is 150mL of petroleum ether and 100mL of toluene.

The chemical reaction equation is as follows:

r is n-dodecyl, ethyl, isooctyl

Example 14

The embodiment is the application of the self-dispersed nano copper in the preparation of the cutting fluid, the self-dispersed nano copper serving as a core additive can directly participate in the compounding of the cutting fluid, and the excellent anti-tapping torque capacity is embodied in the subsequent tapping torque performance detection. The specific formulation is shown in Table 1 below, and this example illustrates A, B, C, D four sets of formulations.

TABLE 1A, B, C, D compounding ratio of four cutting fluids

Tapping torque performance detection is carried out on A, B, C, D four groups of cutting fluids, the tapping torques of the 4 proportions are tested on a Microtap tapping torquer, and the data shown in the following table 2 are obtained (the smaller the average torque is, the better the torque resistance performance is, and the higher the lubrication degree is):

TABLE 2A, B, C, D test results of tapping torque performance of four groups of cutting fluids

	Ratio A	Ratio B	Ratio C	Ratio D
					Mean torque	104.7	94.3	89.7	88.7

The above results show that a small amount of nano copper can produce a very good improvement in the tapping torque performance of the metal cutting fluid. In the D group proportion, when the proportion of the nano copper reaches 4 parts, the improvement of the tapping torque performance basically reaches the maximum. Compared with the traditional metal working fluid, the tapping torque performance of the product added with the nano copper is improved by at least 16%.

Example 15

In this example, the application of self-dispersed nano-copper in the preparation of wear-resistant and pressure-resistant agents (sulfurized olefin and sulfurized ester) is shown in table 3 below, and two sets of proportions of E, F are given in this example.

TABLE 3E, F formulation of two groups of antiwear and anti-compression agents

Compared with the traditional wear-resistant and pressure-resistant agent (sulfurized olefin and sulfurized ester), the nano copper has the same excellent pressure-resistant and wear-resistant performances. Note: the nano-copper paste contains 12% of sulfur and 5.8% of phosphorus, and when the mixture ratio of the nano-copper paste in the formula reaches 20%, the sulfur content of 6% of the sulfide + sulfide can be reached.

The pressure resistance and the abrasion resistance of E, F two groups of abrasion-resistant and abrasion-resistant agents were tested, and the results are shown in the following table 4.

TABLE 4 pressure and abrasion resistances of two E, F compositions measured by a four-ball machine

	Ratio E	Ratio F
			Kinematic viscosity of formulation	30	30
PD value	400	400

The results show that the two formulas can achieve the same abrasion-resistant and pressure-resistant indexes.

The nano-copper products prepared in the above examples 1 to 13 were odorless and tasteless, and were directly dissolved and dispersed in an organic non-polar solvent such as petroleum ether, pentane, hexane, octane, various base oils, etc. without adding any dispersant. The liquid obtained by dissolution is yellowish and transparent when the mass fraction is 1%, and phenomena such as turbidity, sedimentation, discoloration and the like do not occur in a standing observation experiment for at least two months. In addition, examples 14 and 15 show that the nano-copper prepared by the invention has excellent performance in the preparation of metal cutting fluid and wear-resistant and pressure-resistant agent.

In conclusion, the preparation method of the self-dispersible nano-copper provided by the invention has the advantages that the preparation process is simple, the prepared nano-copper can be directly dissolved in an organic nonpolar solvent, the dispersibility in the solvent is good, and the phenomena of turbidity, sedimentation, color change and the like can not occur. In addition, the performance of the metal working fluid is greatly improved in the preparation of the metal working fluid.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A preparation method of self-dispersible nano-copper with a long organic carbon chain is characterized by comprising the following steps:

the preparation of the HDDP coating agent comprises the following steps: the catalyst is prepared by reacting a carbon-based alcohol compound and phosphorus pentasulfide, wherein the molar ratio of the carbon-based alcohol compound to the phosphorus pentasulfide is 2: 1-8: 1;

the carbon-based alcohol is at least one of dodecyl isomeric alcohol, isooctyl alcohol or n-dodecyl alcohol; or the carbon-based alcohol compound is a mixture of the dodecacarbon isomeric alcohol and ethanol, and the molar ratio of the dodecacarbon isomeric alcohol to the ethanol is 5: 1-4: 1;

5) obtaining a nano copper product;

the molar ratio of the copper source to the HDDP coating agent is 1: 5-5: 1.

2. The method for preparing the self-dispersible nano-copper with the long organic carbon chain according to claim 1, wherein the copper source aqueous solution in the step 1) is selected from any one or more of copper sulfate pentahydrate, copper chloride, copper bromide, copper acetate, copper nitrate and copper acetylacetonate aqueous solution.

3. The method for preparing the self-dispersible nano-copper with the long organic carbon chain according to claim 1, wherein the reducing agent in the step 2) is selected from hydrazine hydrate and sodium hypophosphite (NaH)₂PO₂) Any one or more of sodium borohydride, ascorbic acid (vitamin C) and sodium ascorbate.

4. The method for preparing the self-dispersible nano-copper with the long organic carbon chain according to claim 1, wherein the organic solvent in the step 3) is selected from any one or more of petroleum ether, dichloromethane, trichloromethane, pentane, ethyl acetate, diethyl ether, carbon tetrachloride, benzene, toluene, xylene and base oil.

5. The preparation method of the self-dispersible nano-copper with the long organic carbon chain as claimed in claim 4, wherein the petroleum ether is 60-90 ℃ distillate petroleum ether.

6. The method for preparing the self-dispersible nano-copper with the long organic carbon chain according to claim 1, characterized in that the nano-copper mixture is subjected to liquid separation treatment, and a lower water phase is removed to obtain an upper oil phase; centrifuging the oil phase to obtain supernatant; and concentrating the supernatant to obtain the nano copper paste.

7. The method for preparing the self-dispersible nano-copper with the long organic carbon chain according to claim 6, wherein the collected supernatant is treated to remove the organic solvent.

8. The preparation method of the self-dispersible nano-copper with the long organic carbon chain as claimed in claim 7, wherein the organic solvent is removed by rotary evaporation, reduced pressure distillation or atmospheric distillation.

9. A self-dispersible nanocopper formulation having a long organic carbon chain, prepared by the method of any of claims 1-8.

10. The nano copper preparation according to claim 9, wherein the nano copper has a particle size of 10 to 50nm, and the mass ratio of pure copper in the nano copper preparation is 20 to 25%.

11. Use of the nano-copper preparation of claim 9 or 10 in the preparation of cutting fluid, wear and pressure resistant agent, coating additive, engine oil additive and oil film bearing oil additive.