Citation
(1998), "New pigments, the colour of which depends on the angle of viewing", Pigment & Resin Technology, Vol. 27 No. 2. https://doi.org/10.1108/prt.1998.12927baf.013
Publisher
:Emerald Group Publishing Limited
Copyright © 1998, MCB UP Limited
New pigments, the colour of which depends on the angle of viewing
New pigments, the colour of which depends on the angle of viewing
Merck KGaA has begun construction of a new pigment-production facility at its Gernsheim plant. Due to start up in mid-1999, it will mark the first use of Merck's "Innovative" process for industrial-scale production of a synthetic, mica-like material. The plant will produce several tons/year of the material, used as a carrier of pigments for paints and cosmetics.
The carrier is made by controlled precipitation of silicon dioxide from the addition of hydrochloric acid to an aqueous solution of sodium silicate (water glass). This is followed by proprietary grinding and classification, resulting in transparent glass flakes that are 350-400nm thick and less than 50µm diameter. Pigments, such as titanium or iron oxides, are then coated on the flakes by conventional methods.
The special form of the flakes gives them their so-called angle dependence the pigments display a variety of colours, depending on the viewing angle. Merck says such effects are not possible with natural mica, which has variable thickness and impurities.