OPTIBENT NT 10 is a high-quality, powdered rheology additive based on an activated phyllosilicate for aqueous, hydraulically hardening binder systems. It improves processability and can achieve a slightly hydrophobic effect. OPTIBENT NT 10 significantly improves the processing properties and the anti-sagging properties of formulations. The product can also reduce the water absorption of systems. Compared with other additives with a hydrophobic effect, OPTIBENT NT 10 can be easily incorporated with low-dusting. It is suitable for aqueous binder systems with a fine particle size distribution. OPTIBENT NT 10 enables within limits a reduction of organic thickeners, and its platelet-shaped structure can also reduce water absorption of hydratized systems.