Heat stable iron oxide pigments of upsilon-Fe2O3 structure, a process for their production and their use

摘要

A pigment useful for coloring building materials such as bricks is a heat-stable isometric iron oxide brown pigment of gamma -Fe2O3 structure which has a silicon content, expresed as SiO2, of 0.1 to 12% and an Al content, expressed as Al2O3, of 0.02 to 5%.