Luxurious effects with new pigments

Borosilicate pigments belong to the group of pearlescent effect pigments which are generally composed of low refractive transparent platelets like mica coated with high refractive metal oxides, e.g. titanium dioxide or iron oxides. This structure enables interference effects leading to selective reflection of distinct colours, thereby creating the typical pearl lustre as frequently found in nature. Depending on the thickness and the type of the metal oxide coating, pearlescent pigments are able to mimic a full range of rainbow colours as well as earth tone and golden colour shades (Fig. 1). For decades, natural mica, an alumosilicate mineral with an intrinsic multi-layer structure, was and still is used as the state-of-the-art substrate for manufacturing traditional pearlescent pigments. Due to naturally occurring deviations, this material unavoidably displays some basic deficiencies. Mainly concerned are variations in the composition, irregular shaped micro-scale platelets with many scattering edges created during the milling process and, moreover, thickness deviations. Mirage pigments are based on innovative artificial borosilicate platelets with well-defined characteristics. Thanks to excellent surface smoothness, uniform individual particle thickness as well as a high degree of transparency, these achromatic flakes represent an ideal substrate for achieving optimum pearlescent effects. The visual appearance of the new borosilicate pigments (Fig. 2b) compared to traditional natural mica-based pearlescent pigments (Fig. 2a) stands out in a microscopic view. The titanium dioxide coated mica pigment with red interference colour on the left hand side shows a significant colour deviation from particle to particle caused by the background colour of individual mica flakes and by inhomogeneous metal oxide coating layer thickness. In contrast, the titanium dioxide coated borosilicate flakes on the right hand side appear in almost uniform red colour due to the achromatic nature of the artificial substrate and to the homogenous thickness of metal oxide coating achieved by the coating technology.

New borosilicate pigments vs. corresponding customary grades

Taking a closer look at available pearlescent pigments on the cosmetic market, it becomes obvious that the new borosilicate pigments not only outperform traditional mica based effect pigments but also other comparable state-of-the-art borosilicate grades (Fig. 2c). This milestone in effect pigment performance is due to Eckart’s proprietary technology leading to extremely smooth pigment surfaces which optimise gloss and offer unique colour purity. The microscopic view of Mirage Glamour Red effect versus a state-of-the-art borosilicate grade with red interference, clearly illustrates the advantages of the Mirage pigments resulting in optimum colour purity and maximum colour strength. In contrast, the effect of the customary grade is significantly weakened by the colour deviations visible in the microscopic scale. The same principles apply for other interference colours of the new advantageous borosilicate product line, such as Glamour Gold, Blue or Green, each offering unique colour intensity and purity due to the homogenously coloured single particles. Another important parameter contributing to the visual properties of the new borosilicate pigments is their tightly controlled narrow particle size distribution. Careful removal of the finest particles is essential to create optimum lustre and eyecatching effects as these small particles, in particular, strongly contribute to the creation of undesirable diffuse scattered light. Thorough separation of coarse particles is essential for achieving an excellent skin feeling. Concerning sensory effects, even a small amount of oversized particles can negatively impact the skin feel.