公开(公告)号：DE3263427D1

公开(公告)日：1985-06-05

申请号：DE3263427

申请日：1982-10-22

Applicant: BASF AG

Inventor： SARNECKI WILHELM DR ,  KOVACS JENOE DR ,  LOESER WERNER DR ,  RUDOLF PETER DR ,  VAETH GUENTER

IPC: C01G49/02 ,  C01G49/06 ,  C01G49/08 ,  G11B5/706 ,  H01F1/11

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 DEG to 600 DEG 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 DEG to 450 DEG C.

公开(公告)号：DE2860071D1

公开(公告)日：1980-11-13

申请号：DE2860071

申请日：1978-07-28

Applicant: BASF AG

Inventor： BRODT RUDOLF DR ,  JAKUSCH HELMUT DR ,  KOESTER EBERHARD DR ,  LOESER WERNER DR ,  OHLINGER MANFRED DR ,  SARNECKI WILHELM DR ,  STECK WERNER DR

IPC: C01G49/08 ,  C01G49/06 ,  G11B5/62 ,  G11B5/70 ,  G11B5/706 ,  H01F1/11

Abstract: A process for the manufacture of acicular ferrimagnetic iron oxide by dehydrating acicular iron(III) oxide hydroxides to give acicular iron(III) oxides, then reducing these iron(III) oxides at from 300 DEG to 650 DEG C. by means of an organic compound which decomposes in this temperature range, and oxidizing the reduced product with an oxygen-containing gas at from 200 DEG to 500 DEG C., wherein the acicular iron(III) oxide hydroxides employed consist of a mixture of goethite and lepidocrocite, containing at least 60% of the latter, and the dehydration is carried out at from 250 DEG to 700 DEG C.

公开(公告)号：DE2218306A1

公开(公告)日：1973-10-25

申请号：DE2218306

申请日：1972-04-15

Applicant: BASF AG

Inventor： DEIGNER PAUL DR ,  LOESER WERNER DR ,  ALTMUELLER HELMUT ,  SCHOETTLE KLAUS ,  UHL KARL DR ING ,  GAWLIK PETER DR ING

IPC: C25D7/00 ,  C23C14/06 ,  G11B5/72 ,  G11B5/74 ,  H01F10/00

Abstract: 1417521 Coated magnetic recording media BADISCHE ANILIN-& SODA-FABRIK AG 13 April 1973 [15 April 1972] 17821/73 Heading C7F A magnetic recording medium comprises a dimensionally stable base coated with a ferromagnetic metal film at least 600 Š thick which in turn is coated with WC. The base may be a disc of Al or Al alloy or a sheet of polyimide or poly(amideimide) and the ferromagnetic layer may be Co-P, or a P, B, or N- containing layer of Co-Ni, Co-Fe, or Co-Ni-Fe, typically 600-6000 Š thick, produced by electro-plating, electroless deposition or vacuum vapour deposition. The WC layer, produced e.g. by electron beam evaporation, may be up to 2500 Š, e.g. 80-1500 Š, and provides wearresistance.