A Feasibility Study for the Preparation of Green Copper-Colored Mica Pearlescent Pigments

Pearlescent pigments encompass a diverse range known for their ability to create an aesthetically pleasing optical appearance due to the facile alignment of numerous platelet-like particles. Consequently, they serve as an ideal choice for imparting robust, lustrous color effects in powder coatings. The synthesis of green pearlescent pigments was conducted in this study, utilizing mica (biotite) and mica-titania flakes coated with a copper oxide thin film. The process entailed the uniform formation of copper (II) chloride through the addition of sodium or potassium hydroxide in the existence of titania, mica, mica-alumina, ammonium molybdate, or mica-titania flakes. Biotite, denoted by the formula K(Mg/Fe)3(A1Si3O10)(OH)2, was selected as the supporting mica. The synthesized pigments were characterized using X-ray diffractometry (XRD) and X-ray fluorescence (XRF) techniques. Evaluations were conducted using polypropylene extrusion with the incorporated pigments, revealing acceptable chemical resistance and distinctive pearl luster effects. The XRD pattern of the Cu/mica pigment exhibited the presence of copper hydroxide covering the mica surface, confirming the formation of the green pearlescent pigments.