Method for preparing dense silver-coated copper powder by one-pot method

A silver-coated copper powder, dense technology, applied in the field of one-pot preparation of dense silver-coated copper powder, can solve the problems of reducing silver use efficiency, fast reaction speed, high cost, etc., to save precious metal silver, increase resistance, improve packaging overlay effect

Active Publication Date: 2014-10-29
江苏凯尚碳科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The patent with the notification number CN101244459B discloses a preparation method of electroless silver-plated copper powder modified by rare earth. The copper powder is cleaned, activated, sensitized and ultrasonically assisted before plating. The process is relatively complicated and the cost is high.
[0006] The patent with the notification number CN1300381C discloses a preparation method of conductive composite copper powder and composite copper conductor slurry. The method adopts the introduction of a reducing agent to reduce silver ions to silver and deposit them on the surface of copper powder to form a coating structure. Strong reducing agents such as formaldehyde and hydrazine hydrate make the reaction speed fast, and it is not easy to reduce the spontaneous nucleation and growth of silver, which reduces the use efficiency of silver.
[0007] The patent with the publication number CN101214547A changes the surface morphology and layout of micron-scale copper-silver particles through chemical reduction, so that it contains a nano-scale surface. Although the surface sintering or melting temperature is reduced, oxygen can easily pass through the surface during high-temperature sintering. Oxidize copper, in addition, the system does not use surfactants or ultrasonic dispersion assistance, the dispersion of the system is poor, and the collision between particles is easy to agglomerate during the preparation process, so that the product particle size distribution is wide

Method used

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  • Method for preparing dense silver-coated copper powder by one-pot method
  • Method for preparing dense silver-coated copper powder by one-pot method

Examples

Experimental program
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Effect test

Embodiment 1

[0025] First prepare the hydroxymethylamine condensate dispersant: take 9 grams of anhydrous ethylenediamine and dissolve it in 9 grams of deionized water, then take 50 grams of formaldehyde solution with a mass fraction of 37%, and add the formaldehyde solution to ethyl alcohol under stirring. In diamine, react for 2 hours and use it as a dispersant for later use.

[0026] Get 18 grams of silver nitrate and 13 grams of 28% ammonia solution and dissolve it in 180 milliliters of deionized water to make silver ammonia solution; get 43 grams of copper sulfate and 33 grams of 28 percent ammonia solution and dissolve it in 500 milliliters of deionized water to make copper ammonia Aqueous solution: 48 grams of ascorbic acid and 12 grams of hydroxymethylamine condensate dispersant solution were dissolved in 500 milliliters of deionized water to prepare a mixed aqueous solution of reducing agent and dispersant. At a stirring speed of 160 rpm, add the cuproammonia aqueous solution to t...

Embodiment 2

[0028] Get 30 grams of silver nitrate and 22 grams of 28% ammonia solution and dissolve it in 300 milliliters of deionized water to make silver ammonia solution; get 43 grams of copper sulfate and 33 grams of 28 percent ammonia solution and dissolve it in 500 milliliters of deionized water to make copper ammonia Aqueous solution: 48 grams of ascorbic acid and 14 grams of hydroxymethylamine condensate dispersant solution were dissolved in 500 milliliters of deionized water to prepare a mixed aqueous solution of reducing agent and dispersant. At a stirring speed of 160 rpm, add the cuproammonia aqueous solution to the mixed water solution composed of a reducing agent and a dispersant, control the temperature at 70° C., and react for 2 hours under stirring to obtain a suspension containing copper powder; Add 35 grams of N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid to the copper powder suspension, then add the silver ammonia solution of silver nitrate to the suspensi...

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Abstract

The invention relates to a method for preparing compact silver-coated copper powder by using the one-pot method. The silver-coated copper powder is in a coated core-shell structure, a core layer is made of copper, and a shell layer is made of silver. The preparation method includes: adding ammoniacal copper solution prepared by copper sulfate into aqueous solution containing reducing agent and dispersing agent to obtain copper powder suspension; adding water-soluble organic chelating agent into the suspension containing copper powder; adding ammoniacal silver solution prepared by silver nitrate into the suspension containing the copper powder to enable silver ions and the copper powder to be in a displacement reaction; after the displacement reaction finishes, additionally adding a certain amount of weak reducing agent to restore residual silver ions into silver; and filtering, washing and drying to obtain silver-coated copper powder with different grain diameters of 0.8-5 micrometers. The obtained silver-coated copper powder is uniform in silver coating of the shell layer, compact, good in conductivity, high in high-temperature oxidation resistance, and capable of being used for preparation of various electrode slurry sintered in the air.

Description

technical field [0001] The invention relates to a method for preparing silver-coated copper powder, in particular to a method for preparing dense silver-coated copper powder in one pot. Background technique [0002] The rapid development of the electronic information industry has driven the development of electronic paste with ultra-fine metal powder as the main functional phase, and with the development of electronic components to miniaturization, precision, and multi-function, the demand for electronic paste The requirements for technical indicators are also getting higher and higher. Common ultrafine metal powders include silver powder, gold powder, palladium powder, nickel powder, aluminum powder, copper powder, etc. Among them, silver powder is widely used in electronic components because of its excellent comprehensive performance. Copper is cheap and has a volume resistivity similar to that of silver, but copper powder is easily oxidized during preparation and use, wh...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B22F9/24B22F1/02
Inventor 林保平吴敏曹艺
Owner 江苏凯尚碳科技有限公司
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