Improving tint strength with TiO₂

Tinting strength is a measure of the ability of a colorant to alter the color of a paint film.

Hiding power and tinting strength are two optical properties used to describe the light-scattering efficiency of a white pigment. While hiding power is a measure of the ability of TiO₂ to opacify a white paint film, tinting strength describes its ability to add whiteness and brightness to the color of a tinted paint.

To achieve the full tinting strength power potential of TiO₂ in coatings, the TiO₂ must:

• be well dispersed initially and
• avoid particle re-agglomeration throughout coating production, storage, application and drying.

Low tinting strength in a coating can be caused by:

• Inefficient Dispersion or Deagglomeration
• Pigment Flocculation

DuPont TiO₂ products are designed to facilitate easy dispersion and to be compatible with other coating components that might induce flocculation or re-agglomeration of the TiO₂ particles.

For more information on how to achieve and maintain TiO₂ dispersion in coatings, please refer to, Enhancing TiO₂ dispersion performance.

The tinting strength test describes TiO₂ light-scattering contribution relative to the light absorbing ability of a colored pigment when a white paint is tinted to about 50% reflectance with the colored pigment. To be sure that flocculation does not give misleading tinting strength results, the tinting strength measurement should be accompanied by some measure of flocculation such as a rub-up test on the partially dried tinted paint.