Development of High-Performance Organic Pigment Pastes for UV-Curable Coating Systems

Abstract

This study presents the development and evaluation of optimized pigment paste formulations for UV-curable nail coatings based on seven organic pigments. The influence of the monomer-oligomer ratio, pigment loading, and dispersants was examined using planetary mixing, high-speed dispersion, and three-roll milling. Paste quality was assessed through rheological measurements, grind gauge analysis, and opacity evaluation.  The results demonstrate that dispersion behavior is strongly pigment-dependent and requires tailored formulation strategies. Stable, cream-like pastes suitable for automated handling were obtained by balancing pigment concentration with base viscosity and dispesrsant performance. Three-roll milling at 20/10 μm gaps and 160 rpm produced only minimal opacity changes (ΔOP = 0.27%), indicating that organic pigments disperse effectively even without intensive mechanical milling. The results establish the first comparative formulation framework for organic pigments tailored to automated production of UV-curable nail coatings. The proposed approach supports the development of stable dispersions with controlled rheological and optical properties enabling efficient and scalable production of coatings for industrial applications.