ABSTRACT
In makeup products, pigments play an essential role because they provide the chromatic modifications necessary for these qualities. Pigments used in current makeup applications can be classified as organic pigments, mineral pigments, and nacrous pigments (Table 1). Twenty years ago, the cosmetic industry introduced the treated pigments. The surface properties of pigments differ with the size and the shape of the pigment particles as produced by the various manufacturing methods. It is know that the behavior of pigments is closely related to surface properties, and can be classified into hydrophilic and lipophilic. It is very important to know these properties of powders when makeup products are formulated. Generally, pigments and substrates used (mica, talc, sericite, borum nitride, etc.) for makeup cosmetics are hydrophilic. The surface properties of these powders can be changed from hydrophilic to hydrophobic with
several of the aforementioned coatings depending upon the final products’ function. There are many processes by which pigments may be surface treated. The most common methods used today are through chemical interactions, electron-charge reactions, mechanochemical processes, and mechanical processes. Other processes are essentially variants of these four basic methods, as witnessed by an introduction in surface treatment manufacturing called ultramicronization. Surface treatments impart easier dispersibility, better stability, and flocculation resistance to pigments. The second basic important advantage for the cosmetic chemist in using treated pigments is in development of hydrophobic systems (e.g., silicon media). Hydrophobic pigments of both types are available, including treated inorganic colors, DC colors, nylon, titanium dioxide, talc, kaolin, mica, and other minerals. These pigments, and the products made with them, show water-resistant properties, improved skin adhesion, improved color consistency, and better smooth skin feel than when uncoated materials were used in the same formulations.
