Multilayer Pearlescent Pigments Narrow Size Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multilayer pearlescent pigments lack enhanced luster and high chroma, as well as significant color flop, due to broad particle size distributions and inadequate optical layer thicknesses, which affect their optical properties and applications in cosmetic formulations, plastics, and coatings.
Innovation Solution
Development of multilayer pearlescent pigments with a narrow volume-averaged size distribution span (ΔD) of 0.7-1.4, featuring a nonabsorbing high-index layer, a low-index layer, an absorbing high-index layer, and an optional protective layer, applied to platelet-shaped transparent substrates, enhancing their optical properties and luster.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional multilayer pearlescent pigments are used, then they provide basic pearlescent effect, but they lack enhanced luster and high chroma
Solution Approach 1:
The patent applies parameter changes by precisely controlling the size distribution span (ΔD) of the platelet-shaped substrates to a narrow range of 0.7-1.4, and by optimizing the optical layer thickness (d≥150 nm). These parameter optimizations enhance light interference effects, producing strong gloss and high chroma while maintaining the multilayer structure's optical properties.
Solution Approach 2:
The patent employs composite materials by creating a multilayer structure consisting of a transparent substrate combined with specific optical coating layers. This composite construction integrates different materials with complementary optical properties to achieve enhanced luster and chroma that cannot be obtained with single-material pigments.
2Illumination intensity
If conventional multilayer pearlescent pigments are used, then they provide basic color effect, but they lack intense color flop
Solution Approach 1:
The patent achieves intense color flop by optimizing the optical layer thickness parameter (d≥150 nm) and the refractive index contrast between layers. This precise parameter control enables strong angle-dependent interference effects, producing vivid color changes when viewed from different angles.
3Manufacturing precision
If broad particle size distribution is used, then manufacturing is easier, but optical properties are degraded
Solution Approach 1:
The patent prioritizes optical properties by implementing strict size classification to achieve a narrow size distribution span (ΔD) of 0.7-1.4. This parameter optimization ensures uniform light interference across all particles, producing enhanced gloss and chroma, though it requires more sophisticated manufacturing control.
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 pigments exhibit strong gloss, high chroma, and intense color flop, offering improved optical performance and appeal in various applications, including cosmetics, plastics, and coatings, by optimizing the refractive indices and layer thicknesses of the coating layers.
Implementation Method 1
multilayer pearlescent pigments exhibit substantially narrower reflection bands in their reflection spectra and therefore develop a more intensely colored effect. The three-layer coating acts itself as an interference system
Implementation Method 2
a nonabsorbing high-index layer A having a refractive index n≧1.8, b) a low-index layer B having a refractive index n150 nm
Implementation Method 3
multilayer pearlescent pigments exhibit substantially narrower reflection bands in their reflection spectra
Data Source
AI summary
Multilayer pearlescent pigments based on platelet-shaped transparent substrates with an optically active coating, where the optically active coating includes at leasta) a nonabsorbing high-index layer A having a refractive index n≧1.8,b) a low-index layer B having a refractive index n<1.8 having an optical layer thickness >150 nm,c) an absorbing high-index layer C having a refractive index n≧1.8 and also,d) optionally an outer protective layer D,wherein the multilayer pearlescent pigments have a cumulative frequency distribution of the volume-averaged size distribution function, with the indices D10, D50, D90 and a span ΔD of 0.7-1.4, the span ΔD being calculated in accordance with the formula ΔD=(D90−D10)/D50. The disclosure further relates to a method for producing these multilayer pigments, and to their use.