Abstract
Inorganic pigments such as yellow iron oxide (α-FeO(OH)), red ocher (α-Fe2O3) and black iron oxide (Fe3O4) are generally used to lend color tones to base makeup cosmetics such as a foundations. However, there can be several problems when trying to use these pigments directly. For example, the color can change remarkably when the pigment is mixed with various kinds of oils such as sebum and the use of large quantities of pigment can make the product feel very bad on the skin. Therefore, it has become necessary to develop novel inorganic cosmetic materials. Lepidocrocite-type titanates, especially potassium lithium titanate (PLT), have been used as starting materials for the preparation of other shape-controlled functional materials. It was found that a tabular crystal of PLT, in an optimized condition, is useful as a cosmetic agent since it has excellent slipping characteristics and high transparency as well as UV-shield effects. In this research, we have studied the synthesis of Fe-doped PLT pigments, which lend brown and beige tones with superior slipping characteristics as well as a lesser tendency toward color change when mixed with oil. We have characterized these novel products. Furthermore, we have established a method to industrially manufacture Fe-doped PLT. We have successfully established a synthesis method and determined the most suitable composition of Fe-doped potassium lithium titanate, which possessed a brown and beige tone color together with a nice feel and natural luster for powdery foundation.
