Method for producing silver particles, and silver particles produced by the method

Patent metadata

Field	Value
Publication number	US-10486235-B2
Application number	US-201415101859-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Dec 11, 2013
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

The present invention provides a method for producing silver particles, including the steps of: mixing a thermally decomposable silver compound and an amine compound to prepare a silver-amine complex as a precursor; and heating the silver-amine complex at a heating temperature equal to or higher than the decomposition temperature of the silver-amine complex to precipitate silver particles, the silver compound being silver carbonate, the amine compound being terminated with a primary amino group on at least one end and containing a predetermined hydrocarbon group R with a carbon number of 4 to 10. In the method of the present invention, silver particles with the particle size controlled to fall within the range of 20 nm to 200 nm in terms of an average particle size can be produced.

H 2 N—R  [Chemical Formula 1]

First claim

The invention claimed is:

1. A method for producing silver particles, comprising the steps of:
mixing a thermally decomposable silver compound and an amine compound to produce a reaction system including a silver-amine complex as a precursor; and
heating the silver-amine complex at a heating temperature equal to or higher than the decomposition temperature of the silver-amine complex to precipitate silver particles,
wherein the silver particles have an average particle size of 70 to 200 nm and have a variation coefficient (CV) of the particle size of 50% or less as defined under Equation 1,
Variation coefficient CV (%)=(standard deviation/average particle size)×100  [Equation 1]

wherein silver carbonate is used as the silver compound,
wherein the amine compound is represented by the Chemical Formula 1:
H 2 N—R  [Chemical Formula 1]

wherein at least one end is a primary amino group, and
wherein R represents a substituent satisfying the condition (1) or (2):
(1) hydrocarbon group with a carbon number of not less than 5 and not more than 10, which has a linear structure, a branched structure or a cyclic structure, wherein R may, in part, contain oxygen, and R may, in part, contain a primary amino group, a secondary amino group or a tertiary amino group; and
(2) hydrocarbon group with a carbon number of 4, which has a linear structure, wherein R may, in part, contain oxygen, and R may, in part, contain a primary amino group or a secondary amino group, and

wherein the heating temperature is in the range of 65 to 160° C., and
wherein the step of heating the silver-amine complex comprises heating the silver-amine complex at a temperature elevation rate of 2.5 to 50° C./minute until the reaction system reaches the heating temperature, and after the heating temperature is reached, the reaction system is heated and held to precipitate the silver particles.

2. The method for producing silver particles according to claim 1 , wherein the amount of the amine compound mixed with the silver carbonate is 1.5 to 10 times the amount of silver in the silver carbonate in terms of a molar amount.

Assignees

• Tanaka Precious Metal Ind

Inventors

• Makita Yuichi
• Ohshima Yuusuke
• Matsuda Hidekazu
• Taniuchi Junichi
• Nakamura Noriaki
• Kubo Hitoshi

Classifications

• H01B1/02

  mainly consisting of metals or alloys · CPC title

• B22F1/056

  Submicron particles having a size above 100 nm up to 300 nm · CPC title

• B22F1/054

  Nanosized particles · CPC title

• B22F1/00

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

• B22F1/102

  Metallic powder coated with organic material · CPC title