公开(公告)号：DE3379946D1

公开(公告)日：1989-07-06

申请号：DE3379946

申请日：1983-06-20

Applicant: BASF AG

Inventor： OHLINGER MANFRED DR ,  VAETH GUENTER ,  RUDOLF PETER DR ,  SARNECKI WILHELM DR ,  JAKUSCH HELMUT DR ,  KOESTER EBERHARD DR ,  MELZER MILENA

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

Abstract: A process for the preparation of acicular ferrimagnetic iron oxides by reducing gamma-iron(III) oxide hydroxide to magnetite, at from 280 DEG to 620 DEG C., by means of an organic compound which is decomposable at this temperature in the presence of iron oxide, and, optionally, a stream of reducing gas, and, if desired, then oxidizing the magnetite with oxygen-containing gases, at from 150 DEG to 450 DEG C., to acicular ferrimagnetic iron oxide of the formula FeOx, where x is from above 1.33 to 1.50, wherein the organic compound used for the reduction is a non-polar glycerol ester of a fatty acid which is introduced into the aqueous reaction suspension during the preparation of the gamma-iron(III) oxide hydroxide.

公开(公告)号：DE3564504D1

公开(公告)日：1988-09-22

申请号：DE3564504

申请日：1985-05-25

Applicant: BASF AG

Inventor： VAETH GUENTER ,  HEINZ ROBERT ING GRAD ,  OHLINGER MANFRED DR ,  RUDOLF PETER DR ,  HOFMANN FRIEDBERT DR DIPL ING ,  MELZER MILENA DIPL ING

IPC: G11B5/84

公开(公告)号：DE3516885A1

公开(公告)日：1986-11-13

申请号：DE3516885

申请日：1985-05-10

Applicant: BASF AG

Inventor： STECK WERNER ,  FESER RAINER ,  LOESER WERNER ,  RUDOLF PETER ,  VAETH GUENTER ,  JAKUSCH HELMUT ,  KOVACS JENOE

IPC: C01G49/00 ,  C01G49/06 ,  C09D5/23 ,  G11B5/706 ,  H01F1/11 ,  C01G49/02 ,  C01G51/00 ,  C08K3/22 ,  C09D7/12 ,  G11B5/84 ,  B05D5/12 ,  C04B35/26

Abstract: The preparation of acicular ferrimagnetic iron oxides which contain cobalt and phosphate ions and, if desired, further additives, and their use for manufacturing magnetic recording media.

公开(公告)号：DE3361135D1

公开(公告)日：1985-12-12

申请号：DE3361135

申请日：1983-01-22

Applicant: BASF AG

Inventor： RUDOLF PETER DR ,  KOVACS JENOE DR ,  VAETH GUENTER ,  OHLINGER MANFRED DR

IPC: C01G49/00 ,  C01G49/06 ,  C09D5/23 ,  G11B5/62 ,  G11B5/706 ,  H01F1/11

Abstract: A modified acicular ferrimagnetic iron oxide which consists of a core of gamma-iron(III) oxide and a surrounding shell of gamma-iron(III) oxide modified by tin dioxide and carbon, and a process for its preparation.

公开(公告)号：DE3063008D1

公开(公告)日：1983-06-16

申请号：DE3063008

申请日：1980-02-07

Applicant: BASF AG

Inventor： RUDOLF PETER DR ,  STECK WERNER DR ,  JAKUSCH HELMUT DR ,  VAETH GUENTER ,  JAECKH CHRISTOF DR

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

Abstract: A process for the manufacture of acicular magnetic iron oxide consisting of a 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 percent by weight of cobalt(II) ions and from 0.1 to 15 percent by weight of iron(II) ions, wherein a solution containing cobalt(II) hydroxide and iron(II) hydroxide is applied to acicular gamma-iron(III) oxide particles and the latter are heated at 100 DEG -220 DEG C.

公开(公告)号：DE3061463D1

公开(公告)日：1983-02-03

申请号：DE3061463

申请日：1980-02-04

Applicant: BASF AG

Inventor： STECK WERNER DR ,  RUDOLF PETER DR ,  HUEBNER WERNER ,  AUTZEN HORST DR ,  JAKUSCH HELMUT DR ,  SCHAEFER DIETER DR ,  VAETH GUENTER

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

公开(公告)号：DE2942646A1

公开(公告)日：1981-04-30

申请号：DE2942646

申请日：1979-10-22

Applicant: BASF AG

Inventor： OHLINGER MANFRED DIPL CHEM DR ,  VAETH GUENTER ,  MUELLER NORBERT DIPL CHEM DR ,  WETTSTEIN EUGEN

IPC: C01G37/00 ,  C01G37/027 ,  G11B5/62 ,  G11B5/706 ,  H01F1/11 ,  C01G37/02

Abstract: A process for the manufacture of ferromagnetic chromium dioxide modified with foreign elements, by reacting oxides of trivalent and hexavalent chromium under superatmospheric pressure at an elevated temperature in the presence of water and of antimony(III) oxide as modifier, with or without other modifiers in an amount not exceeding 15% by weight, wherein the antimony(III) oxide employed as modifier is, to the extent of more than one-third, present as the senarmontite cubic modification, has a specific surface area, measured by the BET method, of from 1.5 to 15 m2/g, and is added in a total amount of up to 0.5% by weight, based on the resulting chromium dioxide.

公开(公告)号：CS180630B2

公开(公告)日：1978-01-31

申请号：CS261974

申请日：1974-04-11

Applicant: BASF AG

Inventor： VAETH GUENTER ,  BACHMANN RUDOLF ,  SENKPIEL WERNER ,  HARTMANN HANS-JOERG ,  FALK ROLAND ,  MOTZ HERBERT

IPC: C09D5/23 ,  G11B5/702 ,  G11B5/62

Abstract: The invention relates to magnetic recording media comprising a non-magnetic base and, applied thereto, a firmly adhering magnetic coating based on a finely divided magnetic pigment and a special binder mixture. This binder mixture consists essentially of 20 to 90 percent by weight of an elastomeric polyurethane which is soluble in a volatile organic solvent, is practically free of isocyanate groups and has been obtained from a linear, aliphatic polyester or polyether and a diisocyanate of 6 to 24 carbon atoms, and of 10 to 80 percent by weight of a vinyl chloride copolymer which contains 50 to 90 percent by weight of vinyl chloride units and 10 to 50 percent by weight of units of one or more diesters of maleic acid with an alcohol of 1 to 3 carbon atoms, or of the reaction product of this binder mixture with a polyisocyanate of 6 to 50 carbon atoms. Magnetic coatings containing such a binder mixture are distinguished by improved surface hardness coupled with improved orientability of the magnetic particles, as a result of which such recording media are particularly suitable for modern video- and audio-recording instruments.

公开(公告)号：DE2446486A1

公开(公告)日：1976-04-15

申请号：DE2446486

申请日：1974-09-28

Applicant: BASF AG

Inventor： VAETH GUENTER ,  HARTMANN HANS-JOERG DIPL ING D ,  UHL KARL DIPL ING DR ,  GUTERMANN WINFRIED ,  BERGER HEINZ ING GRAD

IPC: G11B23/50 ,  G11B5/008

Abstract: The flexible cleaning arrangement (11) is provided with openings for loosening the particles whilst in contact with the surface of the magnetic tape (6) and moves relative to the movement of the magnetic tape (6). The particles loosened from the magnetic tape (6) are continuously sucked through the loosening openings (12). A number of loosening openings (12) can be indirectly altered, preferably by a rapid alternating movement of the cleaning arrangement (11) relative to the surface of the magnetic tape (6).

公开(公告)号：DE2157685A1

公开(公告)日：1973-05-24

申请号：DE2157685

申请日：1971-11-20

Applicant: BASF AG

Inventor： HARTMANN HANS-JOERG DR ,  HARTMANN JOB-WERNER DR ,  FRISCHMANN HARALD DR ,  VAETH GUENTER

IPC: C09D5/23 ,  G11B5/702 ,  G11B5/68

Abstract: Magnetic recording media comprising a non-magnetic support and a magnetic layer based on a dispersion of finely divided magnetic pigment in a binder consisting of a mixture of a special soluble hydroxyl-free polyester urethane.