The use of iron oxide in the field of pigments
Iron oxide as a pigment is widely used in high-end automotive coatings, architectural coatings, anti-corrosion coatings, powder coatings, is a good environmental protection coating, the annual amount of iron oxide pigments in the world more than 100 million tons, second only to titanium dioxide, inorganic pigments The second place. The use of iron oxide as a pigment not only maintains the good heat resistance, weather resistance, and UV absorption of general inorganic pigments, but also can be well dispersed in the oily vehicle. The coating or ink prepared with it has satisfactory transparency. . Coatings made of iron oxide, which has semiconductor properties, have electrostatic shielding due to their high conductivity. A transparent iron oxide pigment capable of absorbing light of certain wavelengths is coated on the interference pearlescent pigment, and if it is mixed with flash aluminum paste, a combination pigment is formed. Car sequin paint made with this combination of effect pigments not only sees differences in transparency, saturation, or hue when viewed directly or sideways, but also see truly different colors, the so-called two-color effect. This lacquer has a very bright color, double color effect gives a full and magnificent texture, and color retention, good light retention.
Iron oxide is a commonly used colorant in glass production. Because the valence and coordination of iron in glass are easy to change, the coloring of glass by iron oxide is complicated. The iron oxide is present in the glass in the general valence states of Fe2+ and Fe3+, the ratio of which depends on the glass composition, the iron oxide content and the melting conditions. Both Fe2+ and Fe3+ strongly absorb ultraviolet light, the absorption band of Fe2+ is at 200 nm, the absorption band of Fe3+ is at 225 nm, and the absorption coefficient of the latter is much larger than the former. Fe2+ has an absorption band at 1 050 nm and 2 100 nm, which strongly absorbs infrared rays. This enables iron oxide-colored glass to absorb both ultraviolet rays and infrared rays. Therefore, it is widely used in manufacturing heat-absorbing glass, sunglasses glass, and industrial protection. Glasses glasses and military anti-IR coatings. At the same time, it has the features of low price, absorption of heat and ultraviolet light. In addition, iron oxide pigments are widely used abroad as colorants and protective agents for wood coating. The use of transparent iron oxide pigments instead of traditional pigments can preserve the clear wood grain of the wood, while the high lightfastness itself makes the color of the furniture unchanged. The ultraviolet rays in the sunlight can decompose the wood lignin and damage the cell structure, resulting in aging of the wood. Nano-iron oxide pigments can protect the wood because they are small and evenly distributed, do not scatter light, and absorb ultraviolet radiation.