Preparation of acicular, ferrimagnetic iron oxides

US4448761A · kind A · utility

Assignee

• BASF SE

Inventors

• Wilhelm Sarnecki · Schifferstadt, DE
• Jenoe Kovacs · Heßheim, DE
• Werner Loeser · Ludwigshafen, DE
• Peter Rudolf · Ludwigshafen, DE
• Guenter Vaeth · Schifferstadt, DE

Key dates

• Filing date: Oct 20, 1982
• Grant date: May 15, 1984
• Expiry date: Oct 20, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/42
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Acicular ferrimagnetic iron oxides are prepared by a process in which iron (III) oxide hydroxide consisting essentially of lepidocrocite is reduced at from 350.degree. to 600.degree. C. by means of an organic compound which is a synthetic polymer with a molecular weight of from 3,000 to 40,000 to give magnetite, which, if desired, is subsequently partially or completely oxidized with an oxygen-containing gas at from 200.degree. to 450.degree. C.