Encapsulated aluminium pigments

Silica encapsulation of aluminium flakes by a new type of sol/gel process provides silver pigments with long-term stability in water-based coatings. This new, heavy metal-free stabilisation technology guarantees gassing stability and optical properties comparable to chromate-passivated pigment types. No degradation under high shear stress can be observed, an important property for circulation lines and pumps of the automotive industry. Finally, the silica-coated pigments show an excellent weather fastness (Florida testing passed) and best adhesion if the pigmented coatings are exposed to humidity tests.