公开(公告)号：DE3889881D1

公开(公告)日：1994-07-07

申请号：DE3889881

申请日：1988-12-13

Applicant: BASF AG

Inventor： MUELLER MICHAEL WOLFGANG DR ,  HOPPE KLAUS-DIETER DR ,  SCHWAB EKKEHARD DR ,  STECK WERNER DR ,  AUWETER HELMUT DR ,  FESER RAINER DR

IPC: B22F9/20 ,  B22F9/22 ,  G11B5/706 ,  H01F1/047 ,  H01F1/06

Abstract: The invention relates to acicular ferromagnetic metallic particles, consisting essentially of iron, with a nickel content of not more than 0.4% by weight and high values for the coercive field strength and magnetisation, and to a process for producing these particles.

公开(公告)号：DE59001833D1

公开(公告)日：1993-07-29

申请号：DE59001833

申请日：1990-04-19

Applicant: BASF AG

Inventor： STECK WERNER DR ,  LERMER HELMUT DR ,  HERMELING DIETER DR ,  GROSSE BRINKHAUS KARL-HEINZ DR

IPC: C07C41/28 ,  C07C43/164 ,  C07C43/168 ,  C07C43/205

公开(公告)号：DE3582605D1

公开(公告)日：1991-05-29

申请号：DE3582605

申请日：1985-02-22

Applicant: BASF AG

Inventor： STECK WERNER DR ,  JAKUSCH HELMUT DR ,  EBENHOECH FRANZ LUDWIG DR

IPC: C01G49/02 ,  C01G51/00 ,  C09C1/24 ,  G11B5/706

公开(公告)号：DE3678329D1

公开(公告)日：1991-05-02

申请号：DE3678329

申请日：1986-05-03

Applicant: BASF AG

Inventor： SCHWAB EKKEHARD DR ,  STECK WERNER DR ,  RUDOLF PETER DR ,  VAETH GUENTER ,  JAKUSCH HELMUT DR ,  KOVACS JENOE DR

IPC: H01F1/06 ,  B22F1/02 ,  B22F9/22 ,  B22F9/24 ,  G11B5/706

公开(公告)号：DE3766537D1

公开(公告)日：1991-01-17

申请号：DE3766537

申请日：1987-05-07

Applicant: BASF AG

Inventor： SCHWAB EKKEHARD DR ,  STECK WERNER DR ,  SCHLOESSER WILHELM ,  FESER RAINER DR

IPC: C01G49/02 ,  C01G49/00 ,  G11B5/706 ,  G11B5/712 ,  H01F1/11

Abstract: Acicular, magnetic iron oxide consisting of a core of gamma-iron(III) oxide and a ferrite shell containing a total of from 0.4 to 12% by weight of cobalt(II) ions and from 0.1 to 15% by weight of iron(II) ions, the percentages being based on the total amount of magnetic material, is prepared by a process in which an iron(II) hydroxide precipitate is applied to the gamma-iron(III) oxide core in a first stage and an iron-(II)/cobalt hydroxide precipitate is applied to the said core in a second stage, and the core is then converted to the ferrite shell by oxidation.

公开(公告)号：DE3801455A1

公开(公告)日：1989-08-03

申请号：DE3801455

申请日：1988-01-20

Applicant: BASF AG

Inventor： STOCKBURGER DIETER DR ,  FESER RAINER DR ,  GRAMMATIS ZAFIRIOS DR ,  MUELLER NORBERT DR ,  OHLINGER MANFRED DR ,  REINICKE HELMUT DR ,  SARTOR KARL-HEINZ ,  SCHLINDWEIN HEINZ ,  STECK WERNER DR

IPC: C01G37/02 ,  C01G37/027

公开(公告)号：DE3640245A1

公开(公告)日：1988-05-26

申请号：DE3640245

申请日：1986-11-25

Applicant: BASF AG

Inventor： HOPPE KLAUS-DIETER DR ,  SCHWAB EKKEHARD DR ,  STECK WERNER DR

IPC: C01G49/06 ,  C09C1/24 ,  G11B5/706 ,  C01G49/02 ,  B05D5/12 ,  C04B35/26 ,  H01F1/09 ,  H01F10/14

Abstract: The invention relates to a process for preparing acicular (needle-shaped) alpha-FeOOH by addition of alkali and oxidants (oxidising agents) to an aqueous iron(II) sulphate solution at a pH of from 5.0 to 6.0, and the use thereof as starting material for the preparation of magnetic materials suitable for magnetic recording media.

公开(公告)号：DE3608540A1

公开(公告)日：1987-09-17

申请号：DE3608540

申请日：1986-03-14

Applicant: BASF AG

Inventor： ARNDT VOLKER DR ,  MEYER BERND DR ,  FESER RAINER DR ,  STECK WERNER DR ,  JAKUSCH HELMUT DR

IPC: C01G49/06 ,  C09C1/24 ,  G11B5/706 ,  H01F1/11 ,  C09C3/00 ,  C09C1/62 ,  C21B15/00

Abstract: Acicular alpha -Fe2O3 is prepared from iron(III) salts by heating an alkaline aqueous suspension of iron(III) hydroxide in the presence of one or more organic substances which form complexes with iron(III) ions to a temperature of 100 DEG C. or less.

公开(公告)号：DE3065058D1

公开(公告)日：1983-11-03

申请号：DE3065058

申请日：1980-08-21

Applicant: BASF AG

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

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

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：DE3788437D1

公开(公告)日：1994-01-20

申请号：DE3788437

申请日：1987-06-11

Applicant: BASF AG

Inventor： MAIR GUNTHER DR ,  STECK WERNER DR

IPC: C01G53/00 ,  A61K49/18 ,  C01G49/00 ,  C01G51/00 ,  C09K9/00 ,  H01F1/36 ,  H01F1/37 ,  H01F1/44

Abstract: Superparamagnetic solid particles of the general formula I MvMnwZnxFeyOz(I) where M is Co and/or Ni, v and w are each from 0 to 0.998, x is from 0.001 to 0.998, y is from 2.001 to 2.998, z is from 3.001 to 4, v+w+x is from 0.002 to 0.999, v+w+x+y is 3, v NOTEQUAL 0 if w=0 and w NOTEQUAL 0 or v=0, polar and nonpolar superparamagnetic liquids which contain the surfactant-coated superparamagnetic solid particles I in the form of a colloidal dispersion in polar or nonpolar liquid media, and processes for the preparation of polar and nonpolar superparamagnetic liquids.