MAGNETIC IRON OXIDES WITH IMPROVED ORIENTABILITY AND A PROCESS FOR THEIR PRODUCTION

摘要

An acicular, magnetic iron oxide pigment containing about 0.1 to 2 % by weight of zinc and phosphate ions is produced by growing seeds and subsequently reducing and optionally reoxidizing acicular FeOOH. Said seeds were formed by precipitation from an iron (II) salt solution in the presence of about 0.1 to 4% by weight of zinc ions and about 0.1 to 2 % by weight of phosphate ions based on the formed seeds.