Metallic pigments: beyond color- the functional attributes of metallic pigments

摘要

For those of us familiar with metallic pigments, particularly aluminum pigments, it is likely that the appearance or aesthetic qualities of this metallic pigment are those that come to mind at first. In most applications metallic pigments are used to impart aesthetic value through the development of one or more of a variety of visual metallic effects. While the coloristic attributes of metallic pigments are critical to most commercial applications they are not the only attributes to consider. Metallics can provide a variety of functional properties to many applications some of which are inherently obvious and others much less so. There is a broad range of metallic pigment commercially available. This range includes pigments made from aluminum, bronze, stainless steel, iron, zinc, lead, nickel, copper and a host of other metals. Metallic pigments are produced in a variety of shapes and sizes ranging from lamellar to spherical to spindle shaped. Of the various pigment geometries, lamellar or flake-like metallics are the most common. It is the three dimensional shape of the metallic pigment particle along with the characteristic properties of the metal itself which provide many of it's functional properties. The lamellar shape is easy to produce and can be easily modified to enhance both it's functional and aesthetic attributes. Among the various advantages of the lamellar shape is it's potential to produce very large surface areas at relatively low concentrations. This is critical to a number of the most important applications such as the ability to reflect a variety of energy forms as well as it's ability to impart the appearance of the parent metal while not contributing significantly to the overall weight.