Coatings are typically made of 4 components: resins, solvents, additives and pigment. Pigments are an essential component in colored paints and coatings. They are finely ground solid powders dispersed within the film-forming material. Paint pigment can deliver color, coverage and various functional properties to coatings while enhancing mechanical strength.
1. Organic (Coloring)Pigments: Represented by titanium dioxide (Titanium White) and lithopone as white pigments, and black pigments such as carbon black and iron oxide black, as well as inorganic and organic pigments in yellow, red, blue, green, and other colors. Organic pigments exhibit superior coloring power, vibrancy, and decorative effects compared to inorganic pigments. However, they may have lower weather resistance, heat resistance, and lightfastness.
2. Inorganic Pigments(Inert Pigments or Fillers): These include natural or synthetic compounds such as complex silicates, calcium carbonate, gypsum, and sulfuric acid. Generally, fillers have poor covering power and coloring strength, primarily serving as fillers and reinforcing agents while also reducing costs.
3. Functional Pigments: In addition to basic properties like coloring and filling, these pigments impart special functions to coatings, encompassing a diverse range of types. A significant category is corrosion-resistant and anti-rust pigments, essential components in the primer coatings for metal corrosion protection. They prevent corrosion of the metal substrate through processes like sacrificial anode action, passivation of the metal surface, corrosion inhibition, and shielding.