Effect Pigment Coating with Diffused Material for High Chroma

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Solution Overview

Problem

Existing methods struggle to enhance the chroma of effect pigments with platelet diameters of 15 microns or less, as deposition of low refractive index materials often leads to agglomeration and require excessive high refractive index materials.

Innovation Solution

Incorporating a diffused third material with a refractive index between 100% to partial diffusion into high refractive index layers, reducing the need for high refractive index material and preventing agglomeration, while maintaining or increasing chroma.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If alternating high and low refractive index distinct layers are deposited on a substrate to increase chroma, then chroma is improved, but agglomeration occurs when platelet diameter is 15 microns or less

Engineering Contradiction:
ImprovechromaVSAvoidagglomeration
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent removes the low refractive index distinct layer from the conventional alternating layer structure. Instead of depositing separate low refractive index layers between high refractive index layers, the invention uses only high refractive index layers with a diffused third material (different from the high refractive index material) incorporated within them. This extraction of the problematic low refractive index layer eliminates the agglomeration issue while maintaining chroma enhancement through the diffused material's optical effects.

Inventive Principle:
Principle #2Taking out (Extraction)

2Illumination intensity

If alternating high and low refractive index distinct layers are deposited to achieve high chroma, then chroma is improved, but excessive high refractive index material is required

Engineering Contradiction:
ImprovechromaVSAvoidhigh refractive index material
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

The patent merges the function of the low refractive index layer with the high refractive index layer by incorporating a diffused third material within the high refractive index layer structure. This consolidation eliminates the need for separate low refractive index layers and reduces the total quantity of high refractive index material required, as the diffused third material contributes to the optical interference effects that enhance chroma.

Inventive Principle:
Principle #5Merging (Combining)

3Illumination intensity

If multiple alternating layers are deposited to increase chroma, then chroma is improved, but manufacturing complexity increases

Engineering Contradiction:
ImprovechromaVSAvoidcoating structure
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent simplifies the coating structure by removing the alternating low refractive index layers from the conventional multilayer design. The resulting structure consists of high refractive index layers with diffused third material, reducing the number of deposition steps and simplifying the manufacturing process while maintaining the chroma enhancement effect.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This approach allows for higher chroma effect pigments with reduced material usage, minimizing agglomeration and achieving desired optical properties without the need for excessive high refractive index layers.

Implementation Method 1

the diffused third material has a range of diffusion between 100 % to partial diffusion into one or both the first and the second high refractive index layers

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

coated with a high refractive index material, generally a metal oxide of refractive index greater than about 1.65

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

it is possible to obtain pigments that are more intense in color (i.e., having higher chroma) by applying alternating high and low refractive index layers on a substrate

Methodology Applied
Scientific EffectInterference: Interference

Data Source

PatentEP3578610B1Effect pigments
Publication Date: 2021.09.01 BASF SE
  • EP3578610B1 patent drawingFigure 1A
  • EP3578610B1 patent drawingFigure 1B
  • EP3578610B1 patent drawingFigure 2A

AI summary

A high chroma effect pigment includes a platelet substrate and an optical coating formed on the platelet substrate. The optical coating includes a first high refractive index layer, a second high refractive index layer on the first high refractive index layer, and a diffused third material having a range of diffusion between 100 % to partial diffusion in the first high refractive index layer, the second high refractive index layer, or both the first and the second high refractive index layers. The first and second high refractive index layers independently have a refractive index of about > 1.65. The diffused third material is SiO2 or a metal oxide is different than the first and second high refractive index layers.