Metallic Silver Particle Synthesis via Segmented Amine Coordination

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Solution Overview

Problem

Existing methods for producing metallic silver fine particles limit the control of particle size and morphology due to the restricted types of amines used, making it difficult to achieve desired properties and high carboxylic acid coating ratios.

Innovation Solution

A method involving the use of alkoxyamines and carboxylic acids with 11 carbon atoms or fewer, where the second amine or carboxylic acid is mixed with metallic silver fine particles and heated to achieve desired particle sizes and morphologies, with an optional washing step to remove unreacted compounds, allowing for surface modification and coating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional methods using silver oxalate and amine complex formation are used, then metallic silver fine particles can be produced with amine coating, but the particle size and morphology are limited by the specific amine type used

Engineering Contradiction:
Improveparticle size controlVSAvoidamine selection flexibility
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The invention divides the coating process into two independent stages: (1) complex formation stage where silver oxalate reacts with amine to form a complex compound that determines particle size and morphology, and (2) coating stage where the complex compound is heated to decompose and leave the amine coating on the formed particles. This segmentation allows independent optimization of particle formation and surface coating.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The complex compound is formed in advance before particle decomposition. The complex compound contains both the silver precursor and the amine coating agent in a predetermined ratio and configuration. When heated, this pre-formed complex simultaneously achieves particle formation and coating deposition, enabling precise control over final particle properties.

Inventive Principle:
Principle #10Preliminary action

2Temperature

If the complex compound decomposition method is used, then amine coating can be achieved under mild conditions, but it is difficult to obtain particles with high carboxylic acid coating ratio

Engineering Contradiction:
Improvecoating temperatureVSAvoidcarboxylic acid coating ratio
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The invention changes the chemical composition parameters of the complex compound by incorporating carboxylic acid or its derivatives into the complex formation reaction. By adjusting the types and ratios of amines and carboxylic acids in the complex compound, the coating properties can be controlled. The complex compound is designed to contain multiple functional components that will be deposited together upon heating.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If arbitrary amines are desired for coating, then the particle size and morphology cannot be independently controlled

Engineering Contradiction:
Improveamine selection freedomVSAvoidparticle morphology control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention separates the functions of particle formation and surface coating into distinct stages. The first stage (complex formation) controls particle size and morphology through the chemical reaction between silver oxalate and amine. The second stage (thermal decomposition) transfers the amine coating to the formed particles. This allows independent selection of amine types for coating purposes without compromising particle formation control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The complex compound acts as an intermediary carrier that holds both the silver precursor and the amine coating agent together in a specific configuration. During thermal decomposition, this intermediary releases the components in a controlled manner, ensuring that the amine coats the formed particles rather than interfering with the formation process. This intermediary enables the decoupling of particle formation control from coating material selection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables arbitrary coordination and coating of amines on metallic silver fine particles with controlled particle size and morphology, achieving desired synthesis and surface modification while allowing for carboxylic acid coating, thereby improving the properties of the particles for applications like conductive inks and bonding materials.

Implementation Method 1

reacting silver oxalate and an amine to form a complex compound

Methodology Applied
Scientific EffectComplex formation: Chemical Bonding

Implementation Method 2

thermally decomposing the thus produced complex compound

Methodology Applied
Scientific EffectThermal decomposition: Thermolysis

Implementation Method 3

arbitrary amines can be coordinated to and coated on metallic silver fine particles

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3498398B1Method for producing metallic silver fine particles
Publication Date: 2021.04.14 BANDO CHEM IND LTD
  • EP3498398B1 patent drawingFigure 1
  • EP3498398B1 patent drawing

AI summary

Provided is a method for producing metallic silver fine particles in which, arbitrary amines can be coordinated to and coated on metallic silver fine particles having an arbitrarily synthesized particle size and particle morphology, without changing the particle size or the particle morphology, and also both the synthesis of metallic silver particles having a desired particle size and particle morphology and the surface modification of desired metallic fine particles can be achieved. The present invention pertains to a method for producing metallic silver fine particles, the method being characterized by including: a first step for heating and decomposing a complex compound including silver oxalate and a coordination compound to obtain metallic silver fine particles (i); and a second step for mixing at least one type of amine (2a) or a carboxylic acid (2b) with the metallic silver fine particles (i) to obtain metallic silver fine particles (ii) in which at least a portion of the coordination compound of the metallic silver fine particles (i) is substituted with the amine (2a) or the carboxylic acid (2b).