On the premise of keeping properties of color development of pigments, increased pigment concentration of mill base means increasing production efficiency and reducing cost. Pigment concentration of mill base depends on wetting capability of selected dispersant and grinding resin. The main reason for increased viscosity in mill base system is because of phenomenon of pigments aggregation. Using Hyperdispersant will remove free energy on surface of pigment particles to the fullest extent, block re-aggregation of pigment particles to reduce system viscosity and increase pigment concentration in mill base. In some cases, mill base with higher pigment concentration could be obtained without resin.
It is necessary to explain that viscosity of mill base is not the lower, the better, because over low viscosity will decrease inner shear forces of mill base to impact the speed of pigment particles breaking down to tiny one.