The preparation method of silver powder

A technology of silver powder and silver nitrate, which is used in metal processing equipment, transportation and packaging, etc., can solve the problems of affecting the performance of silver powder, inability to settle, and high proportion of organic residues on the surface of silver powder.

Active Publication Date: 2022-06-24
南通领跑者新材料科技有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] When using a water-based dispersant, in order to obtain a highly dispersible silver powder, the amount of the dispersant is often relatively large, but after the amount of the dispersant increases, the reaction liquid with water as the solvent will show a gel state, which will lead to silver powder After the reduction is completed, it floats in large quantities in the water and cannot settle
Even after using a certain type and a certain amount of flocculant to make it settle, the proportion of organic residues on the surface of the silver powder will be high, which will affect the performance of the silver powder in the slurry in the later stage

Method used

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  • The preparation method of silver powder
  • The preparation method of silver powder

Examples

Experimental program
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Effect test

Embodiment 1

[0032] A preparation method of silver powder, comprising the following steps:

[0033] (1) Take 60L of deionized water and 4Kg of silver nitrate, the concentration of silver nitrate is 0.5mol / L, stir evenly, add 250g of gum arabic, and stir to dissolve at 25°C to obtain solution A;

[0034] Take 60L of deionized water and 4Kg of ascorbic acid, mix them evenly, add 360g of gum arabic, and stir at 30°C until dissolved to obtain solution B;

[0035] (2) Take solution B, add solution B to solution A at a rate of 2 L / min, and complete the reaction at 50 °C to obtain suspension C;

[0036] (3) Take 24kg of sodium hydroxide and configure it into a 50% concentration sodium hydroxide solution; add a 50% concentration sodium hydroxide solution to the suspension C to adjust the pH to 14, heat up to 65°C, keep stirring for 0.5h , after the supernatant is clarified, extract the supernatant, collect silver powder, wash, suction filter, and dry to obtain the finished product.

Embodiment 2

[0038] A preparation method of silver powder, comprising the following steps:

[0039] (1) Take 60L of deionized water and 4Kg of silver nitrate, the concentration of silver nitrate is 0.5mol / L, stir evenly, add 250g of gum arabic, and stir at 32°C to a dissolved state to obtain solution A;

[0040] Take 60L of deionized water and 4Kg of ascorbic acid, mix them evenly, add 360g of gum arabic, and stir at 34°C until dissolved to obtain solution B;

[0041](2) Take solution B, add solution B to solution A at a rate of 2.5L / min, and complete the reaction at 55°C to obtain suspension C;

[0042] (3) Take 24kg of sodium hydroxide and configure it into a 50% concentration sodium hydroxide solution; add a 50% concentration sodium hydroxide solution to the suspension C to adjust the pH to 14, heat to 72°C, keep stirring for 1.5h , after the supernatant is clarified, extract the supernatant, collect silver powder, wash, suction filter, and dry to obtain the finished product.

Embodiment 3

[0044] A preparation method of silver powder, comprising the following steps:

[0045] (1) Take 60L of deionized water and 4Kg of silver nitrate, the concentration of silver nitrate is 0.5mol / L, stir evenly, add 250g of gum arabic, and stir to dissolve at 35°C to obtain solution A;

[0046] Take 60L of deionized water and 4Kg of ascorbic acid, mix them evenly, add 360g of gum arabic, and stir to dissolve at 35°C to obtain solution B;

[0047] (2) Take solution B, add solution B to solution A at a rate of 3 L / min, and complete the reaction at 60 °C to obtain suspension C;

[0048] (3) Take 24 kg of sodium hydroxide and configure it into a 50% concentration sodium hydroxide solution; add a 50% concentration sodium hydroxide solution to the suspension C to adjust the pH to 14, heat up to 75°C, keep stirring for 2h, After the supernatant is clarified, the supernatant is extracted, silver powder is collected, washed, filtered and dried to obtain the finished product.

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Abstract

The invention discloses a method for preparing silver powder. In the scheme, a liquid phase reduction method is adopted first. The main principle is to use silver nitrate and a reducing agent, and add a certain amount of water-based dispersant or oily dispersant to obtain silver powder with certain dispersive properties. , in order to ensure that silver powder with high dispersion and uniform particle size can be obtained, this application chooses to use a water-based dispersant, and the reducing agent is any one or more of ascorbic acid, formaldehyde, hydrazine hydrate, and hydrogen peroxide. After the reduction reaction is completed, continue Add lye to adjust the pH of the suspension C to 8-14. In this process, the system contains hydroxide ions, which can use strong alkalinity to destroy the structure of the dispersant, thereby achieving the effect of dissociation; the present invention not only It can be used in any preparation method of silver powder using water-based dispersant, and can realize complete sedimentation of silver powder, and the organic residue on the surface of the obtained silver powder is more than 0.3% lower than that of silver powder not using this method, which has high practicability.

Description

technical field [0001] The invention relates to the technical field of silver powder preparation, in particular to a preparation method of silver powder. Background technique [0002] At present, the preparation method of silver powder generally adopts the liquid phase reduction method. In order to improve the dispersion performance of silver powder, a certain amount of water-based or oil-based dispersant is generally added to it. Because the water-based dispersant can obtain high dispersibility and uniform particle size compared with the oil-based dispersant The silver powder is mainly water-based dispersant in the actual preparation process. [0003] When an aqueous dispersant is used, in order to obtain a high dispersibility silver powder, the amount of the dispersant is often relatively large, but after the amount of the dispersant increases, the reaction solution using water as a solvent will show a gel state, which will lead to the silver powder. After the reduction i...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B22F9/24B22F1/145
CPCB22F9/24
Inventor 陶俊其他发明人请求不公开姓名
Owner 南通领跑者新材料科技有限公司
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