公开(公告)号：DE2405623A1

公开(公告)日：1976-01-08

申请号：DE2405623

申请日：1974-02-06

Applicant: BASF AG

Inventor： KOESTER EBERHARD DIPL PHYS DR ,  WUNSCH GERD DIPL CHEM DR ,  DEIGNER PAUL DR ,  UHL KARL DIPL ING DR ,  STECK WERNER DIPL CHEM DR

IPC: H01F10/32 ,  H01F10/02

Abstract: The magnetic matls., for magnetic recording media, consisting of a non-magnetic substrate and >=2 layers, one of a ferromagnetic phase A and one of an antiferromagnetic phase B, which have a common boundary and thus are coupled magnetically, so that a remanence of different value occurs after satn. in the 2 magnetic polarisation directions below a characteristic temp., the Neel temp., have the alloy CoxNi-x as phase A and the oxide (CoO)x(NiO)1-x as phase B (in which x = 0.04-0.98). The layers of phases A and B pref. are 100-2000 angstrom and 40-2000 angstrom thick respectively and a no. of alternating layers can be used. The layer next to the substrate can contain either phse A or phase B. The matls. have an asymmetrical hysteresis loop, due to the effect of exchange anisotropy, and the Neel temp. can be controlled within wide limits by the compsn.

公开(公告)号：DE2365179A1

公开(公告)日：1975-07-10

申请号：DE2365179

申请日：1973-12-29

Applicant: BASF AG

Inventor： KOESTER EBERHARD DIPL PHYS DR ,  WUNSCH GERD DIPL CHEM DR ,  DEIGNER PAUL DR ,  GRAW DIETER DIPL CHEM DR ,  UHL KARL DIPL ING DR ,  STECK WERNER DIPL CHEM DR

IPC: G11B5/62 ,  C09D5/23 ,  C09D7/12 ,  G11B5/706 ,  H01F1/06 ,  H01F1/09 ,  H01F1/33

Abstract: Magnetic materials which essentially consist of a phase A with a ferromagnetic spin system and a phase B with an anti-ferromagnetic spin system, phases A and B interacting by exchange coupling, and the manufacture of such materials. The materials consist essentially of two-phase magnetic single-domain particles, with the alloy [CoxNi1-x] as the ferromagnetic phase A and its oxidized form [(CoO)x(NiO)1-x] as the anti-ferromagnetic phase B, with values of x of 0.04 to 0.96. They are manufactured by surface oxidation of a pigment layer, which at least covers the surface but may extend deeper, having the composition of phase A, to form an oxide layer, at least 40 A thick, of the phase B, followed by heating in an inert gas atmosphere, or by reduction of a corresponding layer of phase B to a layer of phase A. Magnetic single-domain particles of this composition have a Neel temperature which varies with X. As a result, materials are obtained which have an asymmetrical hysteresis loop, attributable to exchange anisotropy, at temperatures which can be varied within wide limits in accordance with the intended use of the material.

公开(公告)号：DE2935357A1

公开(公告)日：1981-09-10

申请号：DE2935357

申请日：1979-09-01

Applicant: BASF AG

Inventor： STECK WERNER DIPL CHEM DR ,  SARNECKI WILHELM DIPL CHEM DR ,  MAROSI LASZLO DIPL CHEM DR ,  OHLINGER MANFRED DIPL CHEM DR ,  AUTZEN HORST DIPL CHEM DR

IPC: G11B5/706 ,  B22F9/22 ,  C01G49/02 ,  C09D5/23 ,  C09D7/12 ,  G11B5/70 ,  H01F1/06 ,  G11B5/62

公开(公告)号：DE2945203A1

公开(公告)日：1981-06-04

申请号：DE2945203

申请日：1979-11-09

Applicant: BASF AG

Inventor： OHLINGER MANFRED DIPL CHEM DR ,  VAETH GUENTER ,  JAKUSCH HELMUT DIPL PHYS DR ,  KOESTER EBERHARD DIPL PHYS DR ,  SARNECKI WILHELM DIPL CHEM DR ,  STECK WERNER DIPL CHEM DR

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

公开(公告)号：DE2935358A1

公开(公告)日：1981-03-26

申请号：DE2935358

申请日：1979-09-01

Applicant: BASF AG

Inventor： STECK WERNER DIPL CHEM DR ,  SARNECKI WILHELM DIPL CHEM DR ,  MAROSI LASZLO DIPL CHEM DR ,  OHLINGER MANFRED DIPL CHEM DR ,  LOESER WERNER DIPL ING DR

IPC: G11B5/706 ,  B22F9/22 ,  C09D5/23 ,  C09D7/12 ,  G11B5/70 ,  H01F1/06 ,  C01G49/02 ,  G11B5/62

Abstract: A process for the manufacture of acicular ferromagnetic iron particles by heating a goethite, provided with a shape-stabilizing surface coating, at 250 DEG -450 DEG C. in an atmosphere containing water vapor at a partial pressure of not less than 30 mbar, to give alpha-iron(III) oxide, and reducing this material with hydrogen at 275 DEG -425 DEG C., and the use of the iron particles thus obtained as magnetic material in the production of magnetic recording media.

公开(公告)号：DE2705967A1

公开(公告)日：1978-08-17

申请号：DE2705967

申请日：1977-02-12

Applicant: BASF AG

Inventor： BECKER HANS-JUERGEN DIPL CHEM ,  JAECKH CHRISTOF DIPL CHEM DR ,  KOESTER EBERHARD DIPL PHYS DR ,  LOESER WERNER DIPL ING DR ,  OHLINGER MANFRED DIPL CHEM DR ,  STECK WERNER DIPL CHEM DR

IPC: C01G49/02 ,  C01G49/00 ,  C01G49/06 ,  G11B5/706 ,  H01F1/11 ,  H01F1/117

Abstract: A process for the manufacture of an acicular magnetic iron oxide containing from 0.5 to 10 percent by weight of cobalt and up to 24 percent by weight of divalent iron, each based on the amount of iron(III) oxide, wherein an aqueous suspension of gamma-iron(III) oxide, containing cobalt(II) and iron(II) ions, the suspension having a hydroxyl ion concentration of more than 3.6x10-6 moles/liter, is heated at from 50 DEG to 100 DEG C. for at least 15 minutes, and the resulting precipitate is filtered off, washed until neutral, dried at below 100 DEG C. and thereafter heated at from 100 DEG to 200 DEG C. The products thus obtained give, even when their cobalt content is low, a very high coercive force, while the effect of temperature on the coercive force and residual induction is very slight.

公开(公告)号：DE2639250A1

公开(公告)日：1978-03-09

申请号：DE2639250

申请日：1976-09-01

Applicant: BASF AG

Inventor： BECKER HANS-JUERGEN DIPL ING D ,  KOESTER EBERHARD DIPL PHYS DR ,  OHLINGER MANFRED DIPL CHEM DR ,  STECK WERNER DIPL CHEM DR ,  SCHOENAFINGER EDUARD DIPL CHEM

IPC: C01G49/06 ,  C01G49/00 ,  G11B5/706 ,  H01F1/34

公开(公告)号：DE2451276A1

公开(公告)日：1976-05-06

申请号：DE2451276

申请日：1974-10-29

Applicant: BASF AG

Inventor： WUNSCH GERD DIPL CHEM DR ,  DEIGNER PAUL DR ,  FALK ROLAND DIPL CHEM DR ,  MAHLER KARL DIPL ING DR ,  LOESER WERNER DIPL ING DR ,  DOMAS FRIEDRICH DIPL ING ,  FELLEISEN PETER DIPL ING ,  STECK WERNER DIPL CHEM DR

IPC: C23C28/00 ,  C23C30/00 ,  G11B5/708 ,  G11B5/84 ,  G11B5/858 ,  H01F41/14

Abstract: A process for the manufacture of rigid magnetic recording media by depositing a cobalt-containing ferromagnetic metal layer on a non-magnetic metallic base disc provided with a cured layer of binder which does not dissolve or swell in organic solvents and contains non-magnetic pigments, and which has been activated, before deposition of the ferromagnetic layer, by treatment with a solution of a palladium (O) complex in an organic solvent, followed by decomposition of this complex, to prepare it to receive the ferromagnetic metal layer which is produced by electroless deposition.

公开(公告)号：DE2426879A1

公开(公告)日：1976-01-02

申请号：DE2426879

申请日：1974-06-04

Applicant: BASF AG

Inventor： LAURER PETER RUDOLF DIPL CHEM ,  SCHULZ GERHARD DIPL CHEM DR ,  WUNSCH GERD DIPL CHEM DR ,  MUELLER FRANZ-JOSEF DIPL CHEM ,  STECK WERNER DIPL CHEM DR ,  IRGANG MATTHIAS DIPL CHEM DR

IPC: B01J31/16 ,  B01J31/18 ,  B01J31/22 ,  B01J31/24 ,  C07C5/03 ,  C07C29/141 ,  C07C29/145 ,  C07C209/36 ,  C07C209/48 ,  C07F15/00 ,  C07B1/00

Abstract: Catalyst for hydrogenation of organic cpds. contains one or more complexes of Pd(O) on an inert carrier. This catalyst is very active, esp. with respect to hydrogenation of organic nitro or carbonyl cpds., nitriles, olefins and cycloolefins. The reaction is highly selective, esp. in the case of aromatic and polycyclic nitro cpds. The Pd(O) complexes are stable and firmly adhere to the carrier. The organic ligands protect Pd atoms against oxidation. The dispersion of Pd atoms is very fine. The pref. ligands include unsatd. ketones of formula (in which R1 and R6 are each H, 1-5C alkyl, phenyl or 5-8C cycloalkyl; and R2, R3, R4 and R5 are each H (pref.) or 1-5C alkyls).