On the basis of particle shape talc’s are normally distinguished as macrocrystalline and microcrystalline in nature. The crystalline structure is defined due to its natural geology i.e. the tectonic movements of earth which allows the hydrothermal fluid to penetrate the mother rock, generating permeability that makes reactions inside the rocks mass possible. These pressures determine a minerals platyness and hence low pressure low platyness and high pressure high platyness or lamellarity. A High lamellar talc will have larger platelets and microcrystalline talc will have small platelets.
Both types of talc have their own unique benefits in various applications. Most commercial deposits of talc are macrocrystalline, whereas deposits of microcrystalline talc are scarce in the world. However, there are few deposits of such type around the world with India being no exception.
Microcrystalline talc’s have key specially in many paints’ formulations:
- The structural properties make them ideal for use in environment friendly coatings where beyond the CPVC they offer combination of high opacity and low porosity.
- Microcrystalline structure enables emission free wall paints with an excellent wet scrub resistance.
- In architectural and industrial primers, it provides barrier properties to improve corrosion resistance and stain blocking.
- Coarser microcrystalline talc’s with lower oil absorption shows good barrier properties in high performance coatings for metal protection.
- Micronized microcrystalline talc’s shows high oil absorptions and can be used a flatting agent in semi-gloss top coats.
- Micronized microcrystalline talc’s can act as Tio2 extenders and provide a better dry hiding power improving formulation costs.
- Coarse microcrystalline talc’s provide barrier optimizing properties in marine paints as well as low surface areas.
SKKU MINERALS produces various grades of microcrystalline talc’s ranging from low whiteness to high whiteness and in varied fineness levels for applications in various industries. For more information, please write us at info@skkuminerals.com