CN-116652203-B - Preparation method of superfine silver powder

Abstract

The invention relates to a preparation method of superfine silver powder, which comprises the following steps of dissolving silver nitrate in deionized water to obtain a metal salt solution, keeping the temperature to be 30-50 ℃, dissolving a reducing agent in deionized water by ⑵, adding a pH regulator to obtain a reducing agent solution, keeping the temperature to be 30-50 ℃, dissolving a dispersing agent and a doping agent in deionized water by ⑶ to obtain a mixed solution, keeping the temperature to be 30-50 ℃, adding the mixed solution into the metal salt solution by ⑷, stirring for 1min, adding the reducing agent solution into the metal salt solution, stirring for reaction to obtain silver powder, washing the silver powder until the conductivity of a washing solution is less than or equal to 10 mu s by ⑸, carrying out solid-liquid separation to obtain an Ag powder filter cake, adding a surface coating agent-absolute ethanol solution into the Ag powder filter cake by ⑹, stirring uniformly, drying, dispersing by airflow, and screening to obtain the superfine silver powder with the particle size of 0.4-0.8 mu m. The method is simple to operate, low in cost, easy to realize industrial production, small in granularity, narrow in distribution and good in dispersibility of the silver powder product.

Inventors

• BAO FEIYAN
• WANG YUE
• WANG GUOQIANG
• GAO JIAWEI
• WANG WEIBIN
• WANG XINHUI
• SHEN YI
• Jiao Chaohui
• LI XINYUE
• TIAN LEI
• MA JINHUI
• YANG KAILIN
• WU JING
• LU WEIHUA
• ZHANG JING
• ZHANG YAHONG
• WU LAIHONG
• FAN XIUJUAN
• SHI XINGWANG
• PENG XIONG
• QIAO TIANYU

Assignees

• 金川集团股份有限公司
• 兰州金川科技园有限公司

Dates

Publication Date

20260505

Application Date

20230626

Claims (5)

1. 1. The preparation method of the superfine silver powder comprises the following steps: ⑴ Dissolving silver nitrate in deionized water to obtain a metal salt solution, and keeping the temperature to 30-50 ℃; ⑵ Dissolving a reducing agent in deionized water, adding a pH regulator to obtain a reducing agent solution, and keeping the temperature to 30-50 ℃, wherein the content of the pH regulator in the reducing agent solution is 10-100 g/L, and the pH regulator is one of sodium hydroxide, ammonia water and ethylenediamine; ⑶ Dissolving a dispersing agent and a doping agent in deionized water to obtain a mixed solution, and keeping the temperature to 30-50 ℃, wherein the content of the doping agent in the mixed solution is 0.1-1.0 g/L, and the doping agent is one of copper nitrate, sodium nitrate, potassium sulfate and copper sulfate; ⑷ Adding the mixed solution into the metal salt solution, stirring for 1min, adding the reducing agent solution into the metal salt solution, and stirring for reaction to obtain silver powder, wherein the stirring condition of adding the reducing agent solution is that the adding speed is 10L/min, the adding time is 2min, the reaction time is 4-20 min, and the stirring frequency is 40Hz; ⑸ Washing the silver powder until the conductivity of the washing liquid is less than or equal to 10 mu s, and carrying out solid-liquid separation to obtain an Ag powder filter cake; ⑹ The Ag powder filter cake is added with a surface coating agent-absolute ethyl alcohol solution, uniformly stirred, dried, dispersed by air flow and screened to obtain the superfine silver powder with the particle size of 0.4-0.8 mu m, wherein the mass concentration of the surface coating agent-absolute ethyl alcohol solution in the step ⑹ is 0.1-10 g/L, the surface coating agent is one of hexadecanoic acid, stearic acid and erucic acid, and the addition amount of the surface coating agent is 0.1-0.5% of the mass of the silver powder.
2. 2. The method for producing an ultrafine silver powder according to claim 1, wherein the silver nitrate content in the metal salt solution of step ⑴ is 150 to 250 g/L.
3. 3. The method for preparing ultrafine silver powder according to claim 1, wherein the reducing agent in the reducing solution in the step ⑵ is 100-200 g/L, and the reducing agent is any one of glucose, ascorbic acid, hydroquinone, hydrazine hydrate, formaldehyde and organic amine.
4. 4. The method for preparing ultrafine silver powder according to claim 1, wherein the content of the dispersing agent in the mixed solution obtained in the step ⑶ is 20-100 g/L, and the dispersing agent is one of polyvinylpyrrolidone, polyethylene glycol, polyethylene amide and gelatin.
5. 5. The method for preparing ultrafine silver powder according to claim 1, wherein the drying condition in the step ⑹ is a temperature of 60-70 ℃ and a time of 15-20 hours.

Description

Preparation method of superfine silver powder Technical Field The invention relates to the technical field of noble metal material preparation, in particular to a preparation method of superfine silver powder. Background With the continuous development of economic globalization, the development of electronic materials has also emerged as an unprecedented development. Conductive paste is a very important branch in electronic materials, and conductive silver paste is attracting attention because of its many excellent properties. The superfine silver powder is used as a functional material with high surface activity and excellent conductivity, and is widely applied to the fields of conductive slurry, energy industry, composite materials, catalysts, antibacterial materials and the like. Silver powder is the most important raw material of the conductive paste, has important influence on parameters such as film forming property, film thickness, electrical property, weldability, adhesive force and the like in the preparation process, and the quality of the silver powder directly influences the properties of the conductive paste and finally the conductor. At present, many silver powder preparation methods at home and abroad mainly comprise a grinding method, an atomization method, an evaporation and condensation method, an electrochemical deposition method, a sol-gel method, a liquid phase reduction method and the like. The liquid phase reduction method has the advantages of simple operation process, low investment, high yield, low loss and good performance, and becomes one of the preparation methods with the most development prospect at present. However, the silver powder prepared by the current liquid phase reduction method has the problems that the particle size distribution is wider, silver powder particles are easy to agglomerate, washing and sedimentation are difficult and the like, which need to be solved. Disclosure of Invention The invention aims to solve the technical problem of providing the preparation method of the superfine silver powder, which is simple to operate, low in cost and easy to realize industrial production. In order to solve the problems, the preparation method of the superfine silver powder comprises the following steps: ⑴ Dissolving silver nitrate in deionized water to obtain a metal salt solution, and keeping the temperature to 30-50 ℃; ⑵ Dissolving a reducing agent in deionized water, adding a pH regulator to obtain a reducing agent solution, and keeping the temperature to 30-50 ℃; ⑶ Dissolving a dispersing agent and a doping agent in deionized water to obtain a mixed solution, and keeping the temperature to 30-50 ℃; ⑷ Adding the mixed solution into the metal salt solution, stirring for 1min, adding the reducing agent solution into the metal salt solution, and stirring for reaction to obtain silver powder; ⑸ Washing the silver powder until the conductivity of the washing liquid is less than or equal to 10 mu s, and carrying out solid-liquid separation to obtain an Ag powder filter cake; ⑹ And adding a surface coating agent, namely an absolute ethyl alcohol solution, into the Ag powder filter cake, uniformly stirring, and drying, dispersing by airflow, and screening to obtain the superfine silver powder with the particle size of 0.4-0.8 mu m. The silver nitrate content in the metal salt solution in the step ⑴ is 150-250 g// L. The content of the reducing agent in the reducing solution in the step ⑵ is 100-200 g/L, and the reducing agent is any one of glucose, ascorbic acid, hydroquinone, hydrazine hydrate, formaldehyde and organic amine. The content of the pH regulator in the reducer solution in the step ⑵ is 10-100 g/L, and the pH regulator is one of sodium hydroxide, ammonia water and ethylenediamine. The content of the dispersing agent in the ⑶ mixed solution is 20-100 g/L, and the dispersing agent is one of polyvinylpyrrolidone, polyethylene glycol, polyethylene amide and gelatin. The content of the doping agent in the mixed solution in the step ⑶ is 0.1-1.0 g/L, and the doping agent is one of copper nitrate, sodium nitrate, potassium sulfate and copper sulfate. The stirring condition for adding the reducing agent solution in the step ⑷ is that the adding speed is 10L/min, the adding time is 2min, the reaction time is 4-20 min, and the stirring frequency is 40Hz. The mass concentration of the surface coating agent-absolute ethyl alcohol solution in the step ⑹ is 0.1-10 g/L, wherein the surface coating agent is one of hexadecanoic acid, stearic acid and erucic acid, and the addition amount of the surface coating agent is 0.1-0.5% of the mass of the silver powder. The drying condition in the step ⑹ is that the temperature is 60-70 ℃ and the time is 15-20 h. Compared with the prior art, the invention has the following advantages: 1. According to the silver powder preparation method, the dispersing agent and the doping agent mixed solution are firstly added into the metal salt solution