Why is Titanium Dioxide used in Paint?

Titanium dioxide is a synthetic white pigment with high hiding power, nontoxic, permanent, and used in many industries including the paints and coatings industry.

Titanium dioxide pigment is a fine white powder. When used in paints, it provides for maximum whiteness and opacity. It gives paint high hiding power, meaning the ability to mask or hide the substrate underneath. It does this more effectively than any other white pigment.

Titanium dioxide pigment is by far the most important material used by the paints industry for whiteness and opacity. These unique properties are derived from the refractive index of titanium dioxide. The refractive index refers to a substances ability to bend and scatter light. Titanium dioxide has the highest refractive index of any material known to man, greater even than diamond. To take advantage of this property, titanium dioxide must be mined, refined and ground to a fine, uniform particle size.

Titanium dioxide white pigments are developments of the 20th century, and because of their high hiding power, low toxicity and reasonable cost, they have eclipsed other traditional white pigments.

· Titanium dioxide is a rutile pigment that:

· Imparts maximum brightness and a neutral tone in white coatings,

· Produces brilliant, clean tints,

· Is readily dispersed and meets all requirements of modern production methods,

· Gives very high hiding power and is thus economical in use,

· Produces low-haze, high-gloss coatings, and

· Is suitable for all oil, solvent and water-borne paints and coatings for outdoor use.

Why is Titanium Dioxide used in Paint?

Titanium dioxide (TiO2) and other white pigments make the paint films opaque by diffusely reflecting light. This reflection occurs because the white pigment disperses or bends light. If there is enough white pigment in a paint film, almost all visible light striking it (except for a very small amount absorbed by the pigment) will be reflected, and the film will appear opaque, white, and bright.

The primary control of opacity and brightness in white paint films depends on scattering of light. Scattering of light means bending of light, and in coatings, light can be bent by surface reflection, by refraction and by diffraction.

[Information sourced: Esaar]

Chemgrit Coatings supplies a variety of raw materials and additives to the paints and coatins industry. For more information contact Chemgrit Coatings on www.chemgritsa.co.za or athol@chemgritsa.co.za.