TiO2 Increasing durability of coatings
Durability is a term applied to the various changes in appearance and functional value of exposed pigmented powder coatings. It includes all aspects of exterior serviceability, such as retention of color, retention of gloss, chalking, adhesion and film integrity. The initial effects are usually caused by degradation of the organic binder on exposure to sunlight, moisture, temperature change and environmental pollutants.
Chalking occurs as increased amounts of organic binder are removed from the surface of the film, leaving behind exposed TiO2 and extender particles. Since these particles are white, this produces a powdery, chalky appearance. This causes color change and reduces gloss.
Rutile TiO2 is inherently more chalk-resistant than anastase as it absorbs significantly more UV-A ultraviolet radiation, converting it into relative harmless energy in the form of heat and protecting the organic portions of the paint film from UV degradation.
Excellent paint film durability begins with selecting the right ingredients for the job. By selecting a durable TiO2 grade, you can easily get real improvements in gloss retention and chalk resistance