#functionaladditives

Outdoor and industrial coatings are permanently subjected to most stringent environments: strong sunlight, heavy rains, humidity, temperature variations, atmospheric pollutants. Over time, such components can cause coatings to lose their intergrity and develop issues such as fading, chalking, cracking blisters and surface erosion. Some of these challenges are addressed through the use of functional mineral additives.

Among the useful minerals in weather-resistant coverage are silica, talc and advanced silicate mineral. Such additives reinforce coating film, enhance barriers to chemical penetration, and shield the binder system from environmental injury. They are not only cost and performance optimizers but also act as agents in high quality exterior and protective coating.

Silica is desirable for its hardness, stability of chemical nature and high surface area. Film formers on the outside surface layer are used to enhance the ultraviolet resistance of coatings by shielding a polymer binder from degradation, resulting in lower chalking and gloss loss. It also stiffens the film to help it resist grinding from windborne dust and gravel. Its low water absorption helps the product to resist moisture without penetration, keeping it dry and free from blistering, etc., when used in wet areas.

Contribution by talc, a layered silicate mineral to both the flexibility of the coating and water resistance is also important. It forms a plate like structure in the coating film to create a layered barrier which retards the passage of water, air and contaminants. This structure permits the coating to stretch and contract under the influence of a temperature range without cracking. Talc also enhances the look and feel of the surface, improving slip/gription to reduce scouring/fretting wear, as well as providing more consistent surface finish that can last longer.

Silica when used in combination with talc will have a synergistic effect. Silica provides strength and UV resistance, while talc improves flexibility and barrier properties. Due to this balanced blend, coatings maintain their aesthetic color and protective properties in extreme climates.

Other silicate minerals mica, wollastonite and kaolin provide added weather resistance. Water resistance and crack prevention are enhanced by mica; mechanical strength, thermal stability by wollastonite and film integrity, smoothness of application is eventually supported by kaolin. These minerals combined provide strong and robust coating systems.