Heat-stable iron oxide yellow pigments

摘要

Pure-coloured iron oxide yellow pigments having a silking index of less than 5 and a heat resistance of greater than 220 DEG C. in polyethylene for at least 5 minutes are obtained by oxidation of metallic iron with nitrobenzene in an acid medium in the presence of compounds of elements chosen from main groups 3 and 4 of the periodic table.