Metal Pigment Coating Reduces Agglomeration

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Solution Overview

Problem

Metal pigments, particularly those produced using physical vapor deposition (PVD) processes, tend to agglomerate strongly, making concentration and storage difficult, and existing coatings do not provide sufficient stability under aggressive conditions such as high pH values or in powder coatings, which affects their optical properties and integration into coating systems.

Innovation Solution

The use of precondensed heteropolysiloxanes, comprising aminosilane and alkylsilane components, applied to a metal oxide coating layer on metal pigments, enhances stability and reduces agglomeration, allowing for improved handling and integration into coatings while maintaining optical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If metal pigments are produced using PVD processes, then optical properties are improved, but agglomeration tendency increases

Engineering Contradiction:
Improveoptical propertiesVSAvoidagglomeration tendency
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a specific coating composition as an intermediary substance between the PVD metal pigment particles and their environment. This coating, containing polymethacrylate, polyacrylate, and organofunctional silane, acts as a mediator that prevents direct interaction between pigment particles, thereby reducing agglomeration while preserving the optical properties provided by the PVD process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the surface parameters of the PVD metal pigments by applying a coating with specific chemical composition and properties. This changes the surface energy, chemistry, and physical characteristics of the pigment particles, reducing their tendency to agglomerate while maintaining their optical reflection properties.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional coatings are applied to metal pigments, then corrosion stability is improved, but stability under aggressive conditions (high pH) deteriorates

Engineering Contradiction:
Improvecorrosion stabilityVSAvoidstability under high pH
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent creates a composite coating system combining multiple materials with complementary properties: polymethacrylate provides corrosion resistance, polyacrylate adds flexibility and adhesion, and organofunctional silane provides chemical stability and bonding. This composite structure achieves both corrosion stability and resistance to aggressive high pH conditions that single-material coatings cannot provide.

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If metal pigments are concentrated for storage, then transport efficiency is improved, but agglomeration increases

Engineering Contradiction:
ImproveconcentrationVSAvoidagglomeration
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The coating composition serves as a protective intermediary layer on the pigment particle surfaces, preventing direct particle-to-particle contact even at high concentrations. This mediator layer maintains particle dispersion and reduces agglomeration forces, enabling efficient concentrated storage and transport.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Strength

If existing coatings are used on metal pigments, then mechanical stability is improved, but integration into powder coatings deteriorates

Engineering Contradiction:
Improvemechanical stabilityVSAvoidintegration into powder coatings
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The coating composition is designed with multi-functionality to serve both protective and integrative roles. It provides mechanical stability through a durable film structure while simultaneously offering good integration into powder coating systems through appropriate surface properties and chemical composition, making the metal pigments universally applicable in different coating types.

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 application of precondensed heteropolysiloxanes significantly reduces agglomeration and enhances the stability of metal pigments, enabling their use in high concentrations and dry forms without quality loss, and improves their integration and performance in coatings, especially in powder coatings and under aggressive conditions.

Implementation Method 1

a second coating layer comprising at least one heteropolysiloxane is applied to this enveloping first coating layer

Methodology Applied
Scientific EffectSurface modification: Adsorption

Implementation Method 2

an enveloping first coating layer which comprises at least one metal oxide

Methodology Applied
Scientific EffectCorrosion protection: Oxidation

Implementation Method 3

Metal pigments, particularly those produced using physical vapor deposition (PVD) processes

Methodology Applied
Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Data Source

PatentEP3080209B2Coated metal pigments, method for the production and the use thereof, coating agent and article
Publication Date: 2023.06.14 ECKART GMBH & CO KG
  • EP3080209B2 patent drawingFigure 1
  • EP3080209B2 patent drawingFigure 2A~2C
  • EP3080209B2 patent drawing

AI summary

The present invention relates to coated metal pigments, the production thereof and the use thereof. The present invention further relates to coating agents containing the above-mentioned metal pigments, and articles coated with said coating agents.