NOVEL PRECIPITATED SILICIC ACID FOR THICKENING AND GENERATING A THIXOTROPIC BEHAVIOR IN LIQUID SYSTEMS

摘要

A precipitated silica having a d50-value of from 150 to 2000 nm, a d90-value of from 500 to 7000 nm, a silanol group density of from 2.5 to 8 OH/nm2, and a modified tapped density of less than or equal to 70 g/l is useful for thickening and providing thixotropy in liquid systems and shows superior efficiency at thickening and creating thixotropy compared to existing grades of precipitated silica. The precipitated silica functions best as a thixotrope in non-polar or intermediate polar liquid systems such as unsaturated polyester (UPE) resin systems.