公开(公告)号：DE2905352A1

公开(公告)日：1980-08-21

申请号：DE2905352

申请日：1979-02-13

Applicant: BASF AG

Inventor： RUDOLF PETER DIPL CHEM DR ,  STECK WERNER DIPL CHEM DR ,  KOESTER EBERHARD DIPL PHYS DR ,  OHLINGER MANFRED DIPL CHEM DR ,  JAECKH CHRISTOF DIPL CHEM DR

IPC: C01G49/06 ,  G11B5/68 ,  G11B5/706 ,  H01F1/11 ,  C01G49/00 ,  G11B5/62

Abstract: A process for the manufacture of acicular magnetic iron oxide consisting of core of gamma-iron(III) oxide and a ferrite shell which contains, based on the total amount of magnetic material, from 0.2 to 12 per cent by weight of cobalt(II) ions and from 0.1 to 15 per cent by weight of iron(II) ions, wherein a precipitate of cobalt(II) hydroxide and iron (II) hydroxide is applied to acicular gamma-iron(III) oxide particles and the latter are heated at 100 DEG -200 DEG C.

公开(公告)号：DE2805405A1

公开(公告)日：1979-08-16

申请号：DE2805405

申请日：1978-02-09

Applicant: BASF AG

Inventor： AUTZEN HORST DIPL CHEM DR ,  MOTZ HERBERT DIPL ING DR ,  RUDOLF PETER DIPL CHEM DR ,  SARNECKI WILHELM DIPL CHEM DR ,  STECK WERNER DIPL CHEM DR ,  VAETH GUENTER

IPC: C01G49/06 ,  G11B5/706 ,  C01G49/02 ,  G11B5/62

Abstract: A process for the manufacture of acicular ferrimagnetic iron oxide by converting acicular iron(III) oxide hydroxide at from 300 DEG to 650 DEG C., by treatment with an organic compound which decomposes in this temperature range in the presence of iron oxide, the iron(III) oxide hydroxide used for the reaction being a lepidocrocite which has been heat-treated at from 300 DEG to 700 DEG C.