| 摘要 |
<p>A process for producing a magnetic iron oxide having a dark enough color to provide opacity to thin coatings of the magnetic oxide in a binder comprising the steps of: a) reducing α-Fe2O3 in a non-oxidizing atmosphere using an organic reductant at 250 to 600 °C to form an iron oxide precursor having 25 to 45 mole % Fe+2 based on total Fe (i.e., Fe?+2 and Fe+3¿); b) oxidizing the iron oxide precursor to form η-Fe¿2?O3 until carbon content is from 0.5-3 % by weight of the iron oxide particles; and c) heating the η-Fe2O3 in an inert atmosphere at a temperature of about 400 to 550 °C to a magnetic oxide particle having 10 to 40 mole % Fe?+2¿ based on total Fe.</p> |
