Metal Microparticles Star Polymer Dispersing Agent

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Solution Overview

Problem

Existing dispersion solutions containing fine metal particles face challenges with low yields, instability at higher concentrations, and limited solvent compatibility, which affects their antibacterial efficacy and transparency.

Innovation Solution

Fine metal particles coated with a dispersing agent having a star polymer structure and fatty acid/glyceride, allowing for homogeneous dispersion in various solvents without aggregation, using a process that includes heating and mixing with a fatty acid metal salt in glycerin, followed by extraction and dilution with suitable solvents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fine metal particles are dispersed in a solvent to create an antibacterial composition, then antibacterial power is improved, but the particles tend to aggregate and precipitate, reducing dispersion stability

Engineering Contradiction:
Improveantibacterial powerVSAvoiddispersion stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

A dispersing agent is introduced as an intermediary substance between the fine metal particles and the solvent. The dispersing agent contains both hydrophilic groups (carboxyl, hydroxyl, or amine groups) and hydrophobic groups (alkyl chains), allowing it to adsorb onto the metal particle surfaces while simultaneously being compatible with the solvent system. This dual-nature structure prevents particle aggregation and maintains stable dispersion.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite system consisting of fine metal particles, dispersing agent, and solvent. The dispersing agent forms a coating layer on the metal particles, creating a composite structure that combines the antibacterial properties of metal particles with the stabilizing properties of the dispersing agent, achieving both effectiveness and stability.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the concentration of fine metal particles is increased to enhance antibacterial efficacy, then antibacterial power is improved, but dispersion stability decreases and aggregation occurs

Engineering Contradiction:
Improveantibacterial powerVSAvoiddispersion stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The dispersing agent acts as a mediator that maintains particle separation even at high concentrations. By adsorbing onto particle surfaces and providing steric and electrostatic repulsion, it prevents aggregation that would normally occur at higher concentrations, allowing enhanced antibacterial efficacy without sacrificing stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If conventional dispersants are used to prevent aggregation, then dispersion stability is improved, but transparency and efficient use of silver are compromised

Engineering Contradiction:
Improvedispersion stabilityVSAvoidtransparency
Core Design Contradiction:
Stability of the object's compositionVSIllumination intensity

Solution Approach 1:

The invention changes the key parameters of the dispersing agent - using low molecular weight compounds (50-5000 Da) with specific functional groups rather than conventional high molecular weight polymers. This parameter change allows the dispersing agent to provide stabilization while being transparent and not interfering with the optical properties of the final composition.

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If multiple additives are used to achieve stable dispersion and prevent aggregation, then dispersion stability is improved, but the complexity of the composition increases

Engineering Contradiction:
Improvedispersion stabilityVSAvoidcomposition complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The dispersing agent is designed to perform multiple functions simultaneously: it stabilizes the dispersion, prevents aggregation, maintains transparency, and is compatible with various solvents and resin systems. This multi-functionality eliminates the need for multiple separate additives, simplifying the overall composition while achieving comprehensive performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The solution achieves stable dispersion of fine metal particles across different solvents, maintaining antibacterial efficacy and transparency, even at varying concentrations, and allows for efficient production and use in diverse applications.

Implementation Method 1

adding a fatty acid metal salt of the metal of any one of Ag, Cu or Zn to the glycerin followed by heating and mixing

Methodology Applied
Scientific EffectThermal decomposition: Decomposition (biological)

Implementation Method 2

heating and mixing with a fatty acid metal salt in glycerin, followed by extraction

Methodology Applied
Scientific EffectReduction: Reduction

Implementation Method 3

a dispersing agent having an acid value and an amine value which are both in a range of 0 to 20 mgKOH/g... having a star polymer structure... coordinated on the surfaces thereof

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 4

a glyceride coordinated around the fatty acid or on the particle surface

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 5

extracting the fine metal particles from the glycerin into the solvent

Methodology Applied
Scientific EffectLiquid-liquid extraction: Liquid-Liquid Extraction

Data Source

PatentEP3560636B1Metal microparticles, and dispersion liquid containing metal microparticles and method for producing same
Publication Date: 2022.03.16 TOYO SEIKAN GRP HLDG LTD
  • EP3560636B1 patent drawingFigure 1

AI summary

Fine metal particles of any one of Ag, Cu or Zn having a dispersing agent that is coordinated on the surfaces thereof, the dispersing agent having an acid value and an amine value which are both in a range of 0 to 20 mgKOH/g (wherein when either the acid value or the amine value is 0, the other one is not 0), and a dispersion solution in which the fine metal particles are dispersed. The fine metal particles and the dispersion solution containing the fine metal particles can be diluted with various kinds of solvents of either the water type or the organic type, and feature excellent dispersion property even after having been diluted.