Wet scrub resistance
Pure talcs improve the wet scrub resistance of decorative paints, in contrast to talcs containing chlorite (Mg-Al-Silicate), which is not hydrophobic. E.g. the choice of talc can make the difference between a class 1 and a class 2 paint (according to ISO …).

Mud cracking resistance
Platy talc particles act as bridges between binder agglomerates and strengthen the paint film. The higher the aspect ratio and particle size of the talc, the better the mud cracking resistance.

Matting
Talc gives a silky look to paints. Coarse, lamellar talc particles are very efficient matting agents in high PVC paints. Fine talcs with high surface area can be used to absorb excess binder and give a flattening effect to paints or coatings below critical PVC.

Opacity
Lamellar (high aspect ratio) talcs help to disperse titanium dioxide (spacing effect) to improve hiding power and reduce formulation costs.

Barrier effect
The talc platelets reduce oxygen or water transmission, and protect the binder from UV radiation, thus improving the weather resistance of outdoor paints.

Anti-corrosive
The same barrier effect reduces migration of corrosive agents through steel protective coatings. At the same time, the hydrophobic (unpolar) talc increases the adhesion of the coating film on the steel substrate, while the platelets improve the mechanical strength of the film.

High solids
Double classified, de-dusted talcs with low surface area (low oil absorption) allow a higher filler loading in high solids coatings, resulting in lower VOC emission, lower formulation cost and improved performance at the same time !

Conclusion
The function of talc in coatings depends on its hydrophobicity (=purity) and platyness. Pure, lamellar talcs show the best overall performance. The flotated Ztalcs are ideally suited for paints and coatings and have become the leading products in the European coatings industry.