Method for producing a metal particle

Patent metadata

Field	Value
Publication number	US-9789546-B2
Application number	US-201514644579-A
Country	US
Kind code	B2
Filing date	Mar 11, 2015
Priority date	Nov 8, 2010
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A method for producing a metal particle which includes the steps of: mixing a metal salt and a polycarboxylic acid in a liquid phase; adding a reducing agent to the resultant mixture to deposit metal particles; and drying the deposited metal particles.

First claim

The invention claimed is:

1. A method for producing a metal particle, which comprises the steps of: mixing silver nitrate and a polycarboxylic acid in a liquid phase; adding a reducing agent to the resultant mixture to deposit metal particles; and drying the deposited metal particles to obtain a silver particle which is a non-nucleated, spherical porous material having continuous open pores and has:
a volume cumulative particle diameter D 50 of 0.5 to 9 μm measured by a particle size distribution measurement method using an image analysis;
a tap density of 1.8 to 4.5 g/cm 3 ;
a specific surface area of 2 to 6 m 2 /g measured by a BET method; and
a value K of 3≦K≦15,
wherein the value K is determined from a specific surface area SS and a specific surface area BS, and is represented by a formula (2),
wherein the specific surface area SS is represented by a formula (1), wherein in the formula (1), d is a volume cumulative particle diameter D 50 measured by a particle size distribution measurement method using an image analysis and p is a theoretical density of the silver particle, and in the formula (2), the specific surface area BS is a specific surface area as measured by a BET method, wherein formula (1) and formula (2) are as follows:
SS= 6/ pd   (1)

( SS/BS )×100= K   (2).

2. The method according to claim 1 , wherein the mixing step and the depositing are each carried out at a temperature of 10 to 30° C.; and the drying is carried out at a temperature of 0 to 80° C.

3. The method according to claim 1 , wherein the polycarboxylic acid is at least one polycarboxylic acid selected from the group consisting of citric acid, malic acid, maleic acid and malonic acid.

4. The method according to claim 1 , wherein the reducing agent is ascorbic acid or an isomer thereof.

5. The method according to claim 1 , wherein the polycarboxylic acid is at least one polycarboxylic acid selected from the group consisting of citric acid, malic acid, maleic acid and malonic acid; and wherein the reducing agent is ascorbic acid or an isomer thereof.

Assignees

• Namics Corp

Inventors

• Takahashi Tomoyuki
• Yoshii Akito

Classifications

• B22F1/05

  Metallic powder characterised by the size or surface area of the particles · CPC title

• B22F1/00

  Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties · CPC title

• B22F1/052

  characterised by a mixture of particles of different sizes or by the particle size distribution · CPC title

• B22F3/11

  Making porous workpieces or articles · CPC title

• C22C5/06

  Alloys based on silver · CPC title