Angle-Dependent Interference Pigments High-Low-High Refractive Index Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Angle-dependent interference pigments with inorganic material flakes coated with alternating metal oxide and nonmetal oxide layers suffer from poor color saturation and limited color change, restricting their application in cosmetics and automobile finishes due to sudden refractive index changes at interfaces.
Innovation Solution
The development of angle-dependent interference pigments with a 'high-low-high' refractive index layered structure, where a low refractive index coating is sandwiched between high refractive index coatings, composed of metal oxides, silicates, and aluminates, with a gradual refractive index variation, and an optional protective layer, to enhance color saturation and angle-dependent performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If alternating layers of metal oxides and nonmetal oxides are used to create angle-dependent interference pigments, then the pigments exhibit angle-dependent interference colors, but the sudden change of refractive index at the interface causes poor color saturation and no significant color change in the color changing region
Solution Approach 1:
The coating structure is segmented into multiple layers with alternating high and low refractive indices. By dividing the coating into distinct layers (metal oxide layers and nonmetal oxide layers), the patent creates the necessary optical interference conditions while managing refractive index transitions through controlled layering sequences.
Solution Approach 2:
Different regions of the coating structure are assigned different refractive index characteristics. The metal oxide layers provide high refractive index regions, while nonmetal oxide layers provide low refractive index regions. This local variation in optical properties creates the interference effect while the specific arrangement optimizes color saturation in transitional regions.
2Adaptability or versatility
If alternating layers of metal oxides and nonmetal oxides are used to create angle-dependent interference pigments, then the pigments exhibit angle-dependent interference colors, but the significant difference between refractive indices causes no significant color change in the color changing region
Solution Approach 1:
The coating is segmented into alternating high and low refractive index layers, enabling angle-dependent interference while the specific sequencing and thickness control of these segments ensure significant color changes occur in the transitional regions between layers.
Solution Approach 2:
The patent controls the thickness and refractive index parameters of each layer to optimize optical performance. By adjusting layer thicknesses and refractive index values, the patent achieves both angle-dependent color variation and significant color changes in transitional regions, resolving the contradiction between adaptability and color change significance.
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 high color saturation and significant color changes across viewing angles, suitable for various applications including cosmetics and exterior coatings, with the ability to achieve a color flow effect and improved weatherability.
Implementation Method 1
Angle-dependent interference pigments exhibit two or more interference colors when observed from different viewing angles
Implementation Method 2
due to the significant difference between the refractive indices of the metal oxides layers and the nonmetal oxide layers, there is a sudden change of refractive index at the interface between the layers
Data Source
AI summary
An angle-dependent interference pigment based on transparent or translucent inorganic flake serving as a substrate is provided. The substrate is coated by coatings (A)+(B)+(C) and optionally coating (D), so as to form a “high-low-high” refractive index layered structure. The coatings (A) and (C) consist of metal oxides, silicate, aluminates and/or a mixture thereof. The coating (B) consist of silicon oxide, hydrous silicon oxide, aluminum oxide, hydrous aluminum oxide, magnesium oxide, hydrous magnesium oxide and/or a mixture thereof. The angle-dependent interference pigments have high color saturation in the transitional region and a significantly gradual color change in the color changing region. The present pigments can be used as colored coatings, including printing ink, or can be used in the preparation of plastics, glass, ceramics and the like. The pigment of the present invention is particularly used in the cosmetic industry which has a very high requirement on gradual color change.