Method for preparing flake silver powder with low bulk density

A technology of flaky silver powder and low loose packing, which is applied in the field of preparing flaky silver powder with low bulk density, can solve the problems of complex ball milling process, difficulty in controlling the quality of flaky silver powder, and inability to understand the performance of flaky silver powder, so as to reduce the ball milling cost. Time, improve the efficiency of ball milling, the effect of high purity

Active Publication Date: 2013-06-12
湘潭市泽宇新材料科技有限公司
View PDF11 Cites 36 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the wet ball milling process control is more complicated
Disclosed a kind of preparation method of low porosity ratio flaky silver powder in the patent application document such as application number 200510011011.0, this method adopts wet method ball milling, after a dry method ball milling, its ball milling process is very complicated, it is difficult to control the flaky silver powder. quality of silver powder
In addition, the patent application document with application number 200810097801.9 discloses a preparation method of highly dispersible flake silver powder. The flake silver powder prepared by this method needs to be dispersed by ultrasonic dispersion and air flow to improve the dispersion performance of silver powder, but the prepared by this method The particle size distribution of silver powder is wide, and the sheet diameter is D 50 3-25μ㎡; the bulk density distribution is too wide, and the bulk density is 0.5-1.8 g / cm 3 , it is difficult to meet the requirements for the use of flake silver powder with low bulk density
Another patent application document with application number 200810231718.6 discloses a preparation method of flaky silver powder. The method is to use unsaturated fatty acid as a dispersant in the preparation process of the precursor silver powder and as a dispersant in the ball milling process, but the full text of the document is not included. The important index of bulk density of silver powder is not involved, so it is impossible to know the specific performance of flake silver powder prepared by this method

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] 1. Reduction process: Add 300L of pure water into the reaction vessel, and under stirring conditions, add 50kg of silver nitrate to dissolve it completely; then dissolve 15kg of sodium hydroxide with 60L of pure water to prepare an aqueous solution of sodium hydroxide; Add sodium hydroxide aqueous solution dropwise to the silver aqueous solution; after the dropwise addition is completed, 15L formaldehyde solution undergoes a chemical reaction for 1 hour, then wash the silver powder and dry it at 60°C.

[0023] 2. Ball milling process: Weigh 2kg of silver powder, add 10kg of zirconia with a diameter of Φ3mm into the ball milling tank, add 2L of absolute ethanol as a ball milling solvent, and add 40g of oleic acid as a ball milling aid and 80g of dodecylbenzene Sodium cyclamate was used as an emulsifier, and the set speed was 320 rpm for ball milling for 8 hours. After the ball milling, it was sieved, rinsed with absolute ethanol, and dried at 60°C to obtain flake silver p...

Embodiment 2

[0025] 1. Reduction process: add 300L of pure water to the reaction vessel, and add 50kg of silver nitrate under stirring conditions to make it completely dissolved; then dissolve 30kg of anhydrous sodium carbonate with 120L of pure water to prepare an aqueous solution of sodium carbonate; Add sodium carbonate aqueous solution dropwise to the silver nitrate aqueous solution; after the dropwise addition is completed, 15L formaldehyde solution undergoes a chemical reaction for 1 hour, then wash the silver powder and dry it at 60°C.

[0026] 2. Ball milling process: Weigh 2kg of silver powder, add 12.5kg of zirconia with a diameter of Φ5mm into the ball milling tank, add 2L of pure water as a ball milling solvent, add 20g of polyvinyl alcohol as a ball milling aid and 40g of triethanolamine as an emulsification Agent, ball milling at a set speed of 320 rpm for 10 hours, after ball milling, sieve, rinse with absolute ethanol, and dry at 60°C to obtain flaky silver powder. The silv...

Embodiment 3

[0028] 1. Reduction process: Add 300L of pure water into the reaction vessel, and add 50kg of silver nitrate under the condition of stirring to make it completely dissolve; prepare 120L of 25% ammonia solution and add it dropwise to the silver nitrate solution; After the addition is complete, the silver nitrate solution becomes a clear solution, and then add 15L formaldehyde solution for chemical reaction for 1 hour, then wash the silver powder and dry it at 60°C.

[0029] 2. Ball milling process: Weigh 2.5kg of silver powder, add 12.5kg of zirconia with a diameter of Φ5mm into the ball milling tank, add 2L of isopropanol as the ball milling solvent, add 20g of stearic acid as the ball milling aid and 40g of silane The joint agent is used as an emulsifier, and the set speed is 320rpm for ball milling for 6 hours. After ball milling, it is sieved, rinsed with absolute ethanol, and dried at 60°C to obtain flake silver powder. The silver powder particle size D that this method pr...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
diameteraaaaaaaaaa
particle diameteraaaaaaaaaa
particle diameteraaaaaaaaaa
Login to view more

Abstract

The invention provides a method for preparing flake silver powder with low bulk density. The method comprises the following steps of reducing silver powder, i.e. adding pure water into a reaction container, and adding silver nitrate under a stirring condition to make the silver nitrate completely dissolved; adding a PH(Potential Of Hydrogen) value regulator, stirring, adding formaldehyde serving as a reducer to perform chemical reaction, washing the silver powder and drying; and ball-milling, i.e. weighing the silver powder, adding zirconia, filling in a ball-milling pot, adding a ball-milling solvent, a ball-milling aid and an emulsifier, ball-milling, sieving, washing by using a cleaning solvent, and drying to obtain the flake silver powder. The silver powder prepared in the reducing process by the method is not added with any dispersing agent, has low impurity content and high purity; and moreover, the technical process is simple, the ball-milling time is short, and the method is easily industrialized.

Description

technical field [0001] The invention relates to a method for preparing flake silver powder with low bulk density. Background technique [0002] Flake silver powder is widely used in electronic components such as carbon film potentiometer terminals, membrane switches and filters. The physical properties of flake silver powder are important factors affecting the conductivity of silver paste. When the particle size of the flaky silver powder reaches the submicron scale and the shape is bright flakes, the printing effect, uniformity and flatness of the electronic circuit are significantly improved, and the amount of precious metals can be saved by 30%-50 %. There are many preparation methods of flake silver powder, which are divided into chemical method and mechanical method. The chemical reduction method is to use a special reducing agent to directly reduce the silver salt into flaky silver powder without ball milling in the middle. The mechanical method is divided into dry...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): B22F9/24B22F9/04
Inventor 高官明李清湘吴涛万良标向红印黄建民张木毅伏志宏周少强何其飞闫耿陈一梁涛黄培德伟斌雒黄威
Owner 湘潭市泽宇新材料科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap