Calcium Carbonate in Paints

Calcium carbonate based supplements are defined as follows according to EN ISO 3262;

• Purified chalk powder is a soft natural calcium carbonate obtained from chalk. They are shaped by microcrystalline calcitic crystals (1 micron from one side to the other). Chalk mainly consists of the shells and skeletons of sea creatures.
• Natural crystalline calcium carbonate: a calcium carbonate obtained from limestone or marble. Trigonal rhombic crystals tend to be larger than those of chalk.

When both products are evaluated together, calcium carbonate is the most important reinforcement for surface coatings (paint etc.). Because other reinforcing agents cannot fully meet the requirements of the paint industry. The market share of calcium carbonate in 1998 was 72% (76% of this rate is synthetic precipitated PCC). These are followed by dolomite and talc with 7%.

Calcium carbonate is non-toxic and weather resistant. It shows a good whiteness and low density, has low interaction with binders, pigments and other components in the paint system. It has low electrical charge and oil absorption. It has anti-corrosion effect in accordance with alkaline pH and low abrasion on machinery equipment. But the most striking feature of the mineral; Calcium carbonate reinforcements can be produced in grain distribution and fineness suitable for almost all desired processes. This is particularly useful for regulating physical properties such as dispersion, gloss, and hiding power.

Despite all these advantages it provides in practice, its only negative is acid sensitivity. Otherwise calcium carbonate would be a worldwide supplement for paints. Especially price-performance ratios are almost indispensable. The list of typical applications suitable for this product is therefore quite long.

Typical applications for calcium carbonate in the sealant industry