Amorphous Carbon Graphite Coated Pigments for Cosmetics
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Solution Overview
Problem
Current dark blue/green/grey to black pigments, such as Prussian Blue and chromium oxide, are not suitable for cosmetic applications due to allergenic properties, and carbon black pigments suffer from low gloss and segregation issues, while non-metallic interference pigments lack hiding power and chemical stability.
Innovation Solution
Particles coated with a mixture of amorphous carbon (a-C) and nanocrystalline graphite (nc-graphite) exhibit a dark metallic appearance, improved flowability, and increased hiding power, addressing the limitations of existing pigments by providing a non-magnetic, non-segregating, and electrically conductive-free solution with enhanced UV stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If heavy metal oxide pigments (Prussian Blue, chromium oxide, cobalt-oxide) are used to achieve dark blue/green/black shades, then the desired colour effect is obtained, but the pigments are not suitable for cosmetic applications due to allergenic properties
Solution Approach 1:
The harmful heavy metal components are extracted and removed from the pigment system. Instead of using heavy metal oxides, the invention employs carbon-based materials (carbon black, graphite) combined with interference pigments to achieve the desired dark shades without the allergenic properties of Prussian blue, chromium oxide, and cobalt-oxide
Solution Approach 2:
The invention replaces expensive and harmful heavy metal pigments with more benign carbon-based alternatives. Carbon black and graphite are used as base materials combined with interference pigments to create dark shades that are safe for cosmetic applications while maintaining the desired optical effects
2Reliability
If carbon black or graphite particles are used to create black pearl effect, then the hiding power is improved, but the gloss becomes non-attractive and segregation occurs in cosmetic applications
Solution Approach 1:
The invention merges carbon black or graphite particles with interference pigments into a single composite pigment particle. This combination allows the carbon component to provide hiding power while the interference pigment component provides the desired metallic gloss and colour effect, preventing segregation by creating a unified particle structure
Solution Approach 2:
The invention creates composite pigment particles consisting of carbon black or graphite combined with interference pigments. This composite structure integrates the high hiding power of carbon materials with the aesthetic gloss and colour properties of interference pigments, eliminating the need for separate components and reducing segregation in cosmetic formulations
3Illumination intensity
If non-metallic interference pigments are used to achieve dark shades, then the metallic effect is improved, but the hiding power and chemical stability are insufficient
Solution Approach 1:
The invention creates composite pigment particles where carbon black or graphite serves as the core or matrix material, providing high hiding power and chemical stability. Interference pigments are integrated into this carbon-based structure, allowing the metallic effect to be achieved while the carbon component ensures sufficient hiding power and enhanced chemical stability
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 a-C/nc-graphite coated particles achieve a high gloss and metallic effect with improved hiding power and flowability, making them suitable for various applications including cosmetics without the drawbacks of previous technologies.
Implementation Method 1
particles coated with at least one layer which consists of a mixture of amorphous carbon (a-C) and nanocrystalline graphite (nc-graphite) show a dark metallic appearance
Implementation Method 2
achieve a high gloss and metallic effect
Data Source
AI summary
The present invention relates to pigments based on particles which are coated with at least one layer which consists of a mixture of amorphous carbon (a-C) and nanocrystalline graphite (nc-graphite) and to the use of these pigments in paints, plastics, industrial coatings, automotive coatings, printing inks and cosmetic formulations.