阅读说明：本技术 一种室温下制备微米级单晶铜粉的方法 (method for preparing micron-sized single crystal copper powder at room temperature ) 是由 胡晓斌 洪立芝 于 2019-09-16 设计创作，主要内容包括：本发明涉及一种室温下制备微米级单晶铜粉的方法,将可溶性铜盐和络合剂络合后,加入硝酸钾、表面活性剂,充分搅拌溶解,再加入葡萄糖,在室温下反应制备得到微米级单晶铜粉颗粒。与现有技术相比,本发明制备得到的单晶铜粉粒径大小在1-3微米,表面光滑,分散性好,振实密度高,同时本发明工艺简单,无需高温加热,节省能源,有效的降低了成本,适合工业化生产。(The invention relates to a method for preparing micron-sized single crystal copper powder at room temperature, which comprises the steps of complexing soluble copper salt and a complexing agent, adding potassium nitrate and a surfactant, fully stirring for dissolving, adding glucose, and reacting at room temperature to obtain micron-sized single crystal copper powder particles. Compared with the prior art, the single crystal copper powder prepared by the invention has the particle size of 1-3 microns, smooth surface, good dispersibility and high tap density, and meanwhile, the invention has simple process, does not need high-temperature heating, saves energy, effectively reduces cost and is suitable for industrial production.)

1. A method for preparing micron-sized single-crystal copper powder at room temperature is characterized in that soluble copper salt and a complexing agent are complexed, potassium nitrate and a surfactant are added, the mixture is fully stirred and dissolved, glucose is added, and reaction is carried out at room temperature to prepare micron-sized single-crystal copper powder particles.

2. the method for preparing micron-sized single-crystal copper powder at room temperature as claimed in claim 1, wherein the soluble copper salt is one or more of copper sulfate, copper chloride, basic copper carbonate, copper nitrate or copper acetate, and the concentration of the soluble copper salt solution is 3.9-5 mol/L.

3. The method for preparing micron-sized single-crystal copper powder at room temperature according to claim 1, wherein the complexing agent is one or more of thiourea, thiosemicarbazide, sodium thiosulfate, ammonia water, EDTA, disodium EDTA, citric acid, triethylene tetramine, triethanolamine or EGTA.

4. the method for preparing micron-sized single-crystal copper powder at room temperature according to claim 1 or 3, wherein the complexing agent is preferably thiourea and/or thiosemicarbazide.

5. The method for preparing micron-sized single-crystal copper powder at room temperature according to claim 1, wherein the molar ratio of the soluble copper salt to the complexing agent is 1:1.8-1: 3.

6. The method for preparing micron-sized single-crystal copper powder at room temperature as claimed in claim 1, wherein the molar concentration of potassium nitrate in the soluble copper salt solution is 0.02-0.2 mol/L.

7. The method for preparing micron-sized single-crystal copper powder at room temperature according to claim 1, wherein the surfactant is one or more of polyvinylpyrrolidone, polyvinyl alcohol, gelatin and fluorine-containing surfactant.

8. The method for preparing micron-sized single-crystal copper powder at room temperature as claimed in claim 1 or 7, wherein the mass concentration of the surfactant in the soluble copper salt solution is 0.02-0.2 g/L.

9. The method for preparing micron-sized single-crystal copper powder at room temperature as claimed in claim 1, wherein the molar ratio of glucose to soluble copper salt is 1:0.2-1: 4.0.

10. the method for preparing micron-sized single-crystal copper powder at room temperature according to claim 1, wherein the micron-sized single-crystal copper powder has a particle size of 1-3 μm.

Technical Field

the invention relates to the field of preparation of metal powder materials, in particular to a method for preparing micron-sized single crystal copper powder at room temperature.

Background

In metal powder products, the superfine copper powder becomes a basic functional powder material with wide application, large application potential, high added value and large scale by virtue of excellent physical and chemical properties and some special properties, and is mainly applied to production of powder metallurgy, electronic materials, friction materials, oil-containing bearings, electric contact materials, conductive materials, diamond products, mechanical parts and the like.

The research and development and production of the micron-sized single-crystal copper powder are key technologies which can bring revolutionary changes to copper and copper alloy, have high practical value, and are particularly applied to friction lubrication, heat conduction, electric conduction, electromagnetic interference resistance, human body anti-aging drug development and the like. At present, a plurality of methods are used for preparing micron-sized copper powder, such as a reduction method, an electrolysis method, an atomization method and the like. However, most of the prepared copper powder has irregular shapes or the production process has complex process and high energy consumption, and basically has a non-single crystal structure. Therefore, the research on the production process of the micron-sized single-crystal copper powder with low energy consumption and high quality is very important for widening the application of the whole micron-sized single-crystal copper powder.

Chinese patent CN107876795A discloses a method for preparing single crystal copper powder. The method comprises the steps of simultaneously dripping a copper sulfate aqueous solution and a sodium carbonate aqueous solution into a reaction container, reacting to generate basic copper carbonate, washing a reaction product, and drying water; placing basic copper carbonate on a belt type sintering furnace for calcining to obtain copper oxide fine particles; and adding a reaction solvent ethylene glycol, a reducing agent and a reaction promoter into a closed reaction container, adding copper oxide fine particles, filling protective gas into the reaction container, stirring and heating for reaction to obtain the single-crystal superfine copper powder. And uniformly mixing the single-crystal superfine copper powder, the surface antioxidant dispersant and the solvent, adding the mixture into a roller dispersing machine, carrying out ball milling, dispersing and modifying treatment, and then drying the copper powder in vacuum to obtain the single-crystal monodisperse copper powder. In the preparation process, the temperature needs to be heated to 120-195 ℃, the calcination time is 1-3h, and nitrogen or argon is used as a protective gas. The preparation process is complex, the production energy consumption is large, the efficiency is low, and the prepared single crystal copper powder is easy to oxidize.

Chinese patent CN110125433A discloses a method for preparing nano-copper powder at room temperature, which comprises the steps of complexing a soluble copper salt solution with a complexing agent, adding potassium sulfate, fully stirring for dissolving, adding a hydrazine hydrate solution as a reducing agent, and reacting at room temperature to obtain nano-copper powder particles, wherein the morphology and the particle size distribution of the copper powder prepared by the method are still not uniform enough.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a method for preparing micron-sized single-crystal copper powder at room temperature.

The purpose of the invention can be realized by the following technical scheme:

A method for preparing micron-sized single crystal copper powder at room temperature comprises the following steps:

(1) Adding a complexing agent into a soluble copper salt solution with the concentration of 3.9-5mol/L, and stirring for 15-30 minutes at room temperature;

(2) Adding potassium nitrate into the solution until the concentration of the potassium nitrate is 0.01-0.25mol/L, and stirring for 5-10 minutes at room temperature; the potassium nitrate solution is added, so that the ionic strength of the soluble copper salt can be obviously improved, and the copper powder can be generated at room temperature;

(3) adding a surfactant into the solution until the concentration of the surfactant is 0.02-0.2g/L, and stirring for 15-20 minutes at room temperature; the addition of the surfactant is beneficial to the smooth surface, good dispersibility and high tap density of the prepared single crystal copper powder.

(4) Adding a reducing agent glucose into the solution, wherein the molar ratio of the glucose to the soluble copper salt is 0.5-2, so that the glucose reduces copper ions to obtain micron-sized single crystal copper powder, stirring at room temperature, and reacting for 10-40 minutes;

(5) And separating, washing and vacuum drying the solution to prepare granular single crystal copper powder with the grain diameter of 1-3um, wherein the drying temperature is 50-100 ℃, and the washing solvent is water or alcohol.

The soluble copper salt is one or more of copper sulfate, copper chloride, basic copper carbonate, copper nitrate or copper acetate.

The complexing agent is one or more of thiourea, thiosemicarbazide, sodium thiosulfate, ammonia water, EDTA disodium, citric acid, triethylene tetramine, triethanolamine or EGTA.

Thiourea and/or thiosemicarbazide are/is selected as the complexing agent, the thiourea complexing agent with a smaller complexing constant is adopted, complex ions are more stable, and meanwhile, the thiosemicarbazide is used for forming secondary complexing, so that the reaction is easier to control, and the morphology and particle size distribution of the reduction product copper powder are more uniform.

The mol ratio of the soluble copper salt to the complexing agent is 1:1.8-1: 3.

The molar concentration of the potassium nitrate in the soluble copper salt solution is 0.02-0.2 mol/L.

the surfactant is one or more of polyvinylpyrrolidone, polyvinyl alcohol, gelatin and fluorine-containing surfactant, and the addition of the surfactant enables the appearance and particle size distribution of the produced micron copper powder to be more uniform.

The mass concentration of the surfactant in the soluble copper salt solution is 0.02-0.2 g/L.

The molar ratio of glucose to soluble copper salt is 1:0.2-1: 4.0.

In experiments, the added complexing agent is found to be most preferably thiourea and/or thiosemicarbazide. The mol ratio of the soluble copper salt to the complexing agent is 1:1.8-1: 3. After the complexing agent is added, copper ions play a good buffering role in the reduction process, so that the particle size of the prepared copper powder is more uniform. The invention prepares micron-sized single crystal copper powder at room temperature. The soluble copper salt is complexed with the complexing agent, so that the particle size of the prepared copper powder is more uniform. Potassium nitrate is added to improve the ionic strength of the reaction solution and effectively promote the generation of the copper powder at room temperature. Meanwhile, the surfactant is added into the reaction liquid, so that the prepared single crystal copper powder has smooth surface, good dispersibility and high tap density.

Compared with the prior art, the invention has the following advantages:

1. the obtained single crystal copper powder has uniform particle size, good dispersibility and high tap density.

2. The single crystal copper powder has smooth surface and good conductivity.

3. The product has high purity, high yield, convenient and quick post-treatment and easy control.

4. Simple process, greatly reduced energy consumption, low production cost and easy large-scale production.

Drawings

FIG. 1 is an SEM image of micron-sized single-crystal copper powder prepared in example 3.

Detailed Description

the present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

A method for preparing micron-sized single crystal copper powder at room temperature comprises the following steps:

(1) Adding a complexing agent into a soluble copper salt solution with the concentration of 3.9-5mol/L, stirring at room temperature for 15-30 minutes, wherein in the system, the used soluble copper salt is one or more of copper sulfate, copper chloride, basic copper carbonate, copper nitrate or copper acetate, the complexing agent can be one or more of thiourea, thiosemicarbazide, sodium thiosulfate, ammonia water, EDTA disodium, citric acid, triethylene tetramine, triethanolamine or EGTA, and particularly when the complexing agent with a smaller complexing constant such as thiourea and/or thiosemicarbazide is adopted, complexing ions can be more stable, the reaction is more easily controlled, the morphology and the particle size distribution of the reduction product copper powder are more uniform, and the molar ratio of the soluble copper salt to the complexing agent is 1:1.8-1: 3;

(2) Adding potassium nitrate into the solution until the concentration of the potassium nitrate is 0.01-0.25mol/L, and stirring for 5-10 minutes at room temperature; the potassium nitrate solution is added, so that the ionic strength of the soluble copper salt can be obviously improved, and the copper powder can be generated at room temperature;

(3) adding surfactant to the solution to a concentration of 0.02-0.2g/L, wherein the surfactant can be one or more of polyvinylpyrrolidone, polyvinyl alcohol, gelatin and fluorine-containing surfactant, and stirring at room temperature for 15-20 min; the addition of the surfactant is beneficial to the smooth surface, good dispersibility and high tap density of the prepared single crystal copper powder.

(4) adding a reducing agent glucose into the solution, wherein the molar ratio of the glucose to the soluble copper salt is 1:0.2-1:4.0, so that the glucose reduces copper ions to obtain micron-sized single crystal copper powder, stirring at room temperature, and reacting for 10-40 minutes;

(5) And separating, washing and vacuum drying the solution to prepare granular single crystal copper powder with the grain diameter of 1-3um, wherein the drying temperature is 50-100 ℃, and the washing solvent is water or alcohol.

The following are more detailed embodiments, and the technical solutions and the technical effects obtained by the present invention will be further described by the following embodiments.