公开(公告)号：DE2950174A1

公开(公告)日：1981-06-19

申请号：DE2950174

申请日：1979-12-13

Applicant: BASF AG

Inventor： KOESTER EBERHARD DIPL PHYS DR ,  HACK JOACHIM DIPL ING ,  STEUERWALD MANFRED

IPC: G06K19/10 ,  G06K7/08 ,  G06K19/12 ,  G07D7/04 ,  G11B5/00 ,  G11B23/30 ,  G07D7/00 ,  G06K19/08 ,  B44F1/12

Abstract: A process for authenticating recording media which are to be safeguarded against falsification and which possess discrete regions of an exchange-anisotropic magnetic material, by comparison of the polarity of a residual magnetization which is left over, because of the exchange anisotropy of the magnetic material, from a predetermined initial magnetization after exposure of the material to a specific temperature cycle and, subsequently, to a magnetic AC field which decreases to zero, with the polarity of a residual magnetization formed in the same way from an opposite initial magnetization, and an apparatus for carrying out the said process.

公开(公告)号：DE2909891A1

公开(公告)日：1980-09-25

申请号：DE2909891

申请日：1979-03-14

Applicant: BASF AG

Inventor： KNELLER ECKHART PROF DIPL PHYS ,  KOENIG ROLAND DIPL PHYS DR ,  KOESTER EBERHARD DIPL PHYS DR ,  GRAU WERNER DIPL CHEM DR ,  MAYER DIETER

IPC: G11B5/66 ,  G11B5/64 ,  G11B5/65 ,  G11B5/706 ,  G11B5/73 ,  G11B5/85 ,  H01F1/20 ,  H01F10/12 ,  H01F10/13 ,  H01F10/16 ,  H01F41/20 ,  H01F10/00 ,  B05D5/12 ,  C23C13/02 ,  C03C17/06 ,  C23C15/00

Abstract: A magnetic recording medium comprising a non-magnetic base which is dimensionally stable at up to 300 DEG C., and an 0.03-0.4 mu m thick magnetically hard recording layer of an Sm-Co alloy, vacuum-deposited thereon, which layer possesses uniaxial magnetic anisotropy in the plane of the layer, and a process for the manufacture of this recording medium.

公开(公告)号：DE2754885A1

公开(公告)日：1979-06-13

申请号：DE2754885

申请日：1977-12-09

Applicant: BASF AG

Inventor： HARTMANN JOB-WERNER DIPL CHEM ,  KOESTER EBERHARD DIPL PHYS DR ,  OHLINGER MANFRED DIPL CHEM DR

IPC: B22F1/02 ,  G11B5/706

Abstract: Acicular, magnetic materials, (A) are coated with 0.3-5 (0.5-3) wt.%, w.r.t. (A), of a perfluorocarboxylic acid, perfluoroalkane-sulphonic acid, their salts or acid derivs., having formula (CnF2n+1)-Y-X (I) (where n is integer 4-12; Y is C=O or SO2; X is F, Cl, OZ or NR2; Z is H, alkali metal or NH4 and R is H, alkyl, aminoalkyl, hydroxyalkyl, aralkyl, aryl or isocyanato-alkyl contg. 1-5C in each alkyl gp.). (A) are used in the mfr. of magnetic recording carriers, consisting of a support coated with a layer of finely-divided (A) dispersed in a polymer binder. Packing density in magnetic layer and particle orientation are improved. Remanence increase achieved improves electro-acoustic properties. Tendency to smear is low. Resistance to abrasion is not reduced, and may even be increased. On using acicular CrO2, the stability of remanent magnetic flux on storage under unfavourable climatic conditions is improved.

公开(公告)号：NL7804420A

公开(公告)日：1978-11-20

申请号：NL7804420

申请日：1978-04-25

Applicant: BASF AG

Inventor： HUEBNER WERNER DIPL ING ,  HARTMANN JOB-WERNER DIPL CHEM ,  DOMAS FRIEDRICH DIPL ING ,  NAGEL PETER DIPL ING ,  DEIGNER PAUL DR ,  KOESTER EBERHARD DIPL PHYS DR ,  HAUSER HANS

IPC: G11B5/84 ,  G11B5/842 ,  B01F27/73 ,  G11B5/848 ,  G11B5/62 ,  G11B5/47

Abstract: A process and apparatus for the manufacture of magnetic recording media, in which, immediately before the magnetic dispersion is applied to a base, the dispersion is subjected to shear by means of a disc rotatably mounted in a housing, by introducing it at the center of rotation of the disc and forcing it through a gap formed between the face of the disc and the wall of the housing, which gap tapers toward the rim of the disc.

公开(公告)号：DE2714588A1

公开(公告)日：1978-10-12

申请号：DE2714588

申请日：1977-04-01

Applicant: BASF AG

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

IPC: G11B5/706 ,  B22F9/22 ,  C09D5/23 ,  C09D7/12 ,  C21B15/00 ,  G11B5/712 ,  G11B5/714 ,  H01F1/06 ,  B22F9/00

Abstract: A process for the manufacture of acicular ferromagnetic iron particles by reducing acicular iron(III) oxide hydroxides which consist of pure synthetic lepidocrocite or a mixture of synthetic goethite and at least 70% by weight of synthetic lepidocrocite. The iron(III) oxide hydroxides used carry, on their surface, an alkaline earth metal cation and an anion of a monobasic, dibasic or tribasic aliphatic carboxylic acid of up to 6 carbon atoms or an organic compound containing at least two groups capable of chelating the alkaline earth metal cation, and are produced in such a way that they consist of at least 70 percent by weight of lepidocrocite and have a length-to-width ratio of not less than 15:1. Reduction of such iron(III) oxide hydroxides gives iron particles with pronounced shape anisotropy, which exhibit both good magnetic properties and a narrow field strength distribution.

公开(公告)号：DE2650890A1

公开(公告)日：1978-05-11

申请号：DE2650890

申请日：1976-11-06

Applicant: BASF AG

Inventor： BECKER HANS-JUERGEN DIPL CHEM ,  BRETTSCHNEIDER HELMUT ING GRAD ,  KOESTER EBERHARD DIPL PHYS DR ,  STECK WERNER DIPL CHEM DR ,  OHLINGER MANFRED DIPL CHEM DR

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

公开(公告)号：DE2446488A1

公开(公告)日：1976-04-08

申请号：DE2446488

申请日：1974-09-28

Applicant: BASF AG

Inventor： KOESTER EBERHARD DIPL PHYS DR ,  DEIGNER PAUL DR ,  FALK ROLAND DIPL CHEM DR ,  HUBER GEORG ,  UHL KARL DIPL ING DR

IPC: G01R33/12 ,  G11B5/00 ,  G11B5/84 ,  G01R33/02

公开(公告)号：NL181608C

公开(公告)日：1987-09-16

申请号：NL7804420

申请日：1978-04-25

Applicant: BASF AG

Inventor： HUEBNER WERNER DIPL ING ,  HARTMANN JOB-WERNER DIPL CHEM ,  DOMAS FRIEDRICH DIPL ING ,  NAGEL PETER DIPL ING ,  DEIGNER PAUL DR ,  KOESTER EBERHARD DIPL PHYS DR ,  HAUSER HANS

IPC: G11B5/84 ,  B01F27/73 ,  G11B5/842 ,  G11B5/848

Abstract: A process and apparatus for the manufacture of magnetic recording media, in which, immediately before the magnetic dispersion is applied to a base, the dispersion is subjected to shear by means of a disc rotatably mounted in a housing, by introducing it at the center of rotation of the disc and forcing it through a gap formed between the face of the disc and the wall of the housing, which gap tapers toward the rim of the disc.

公开(公告)号：DE3217099A1

公开(公告)日：1983-11-10

申请号：DE3217099

申请日：1982-05-07

Applicant: BASF AG

Inventor： MELZER MILENA DIPL ING ,  JAKUSCH HELMUT DIPL PHYS DR ,  GRAU WERNER DIPL CHEM DR ,  KOESTER EBERHARD DIPL PHYS DR ,  LOESER WERNER DIPL ING DR ,  POLKE REINHARD DIPL PHYS DR ,  SCHAEDEL GUENTER DIPL ING DR ,  OHLINGER MANFRED DIPL CHEM DR ,  VAETH GUENTER

IPC: G11B5/70 ,  C09D5/23 ,  G11B5/68 ,  G11B5/706 ,  G11B5/84 ,  H01F1/11 ,  H01F1/113 ,  H01F1/44 ,  H01F41/16

Abstract: A magnetic dispersion which can be applied to a non-magnetic base to produce a recording medium is prepared by dispersing a magnetically anisotropic material in a polymer binder and in an organic solvent by a method wherein the magnetically anisotropic material is worked in a jet mill before and/or during dispersing.

公开(公告)号：DE3151590A1

公开(公告)日：1983-07-07

申请号：DE3151590

申请日：1981-12-28

Applicant: BASF AG

Inventor： MELZER MILENA DIPL ING ,  SCHNEIDER NORBERT ,  KOPKE HELMUT ,  SCHOETTLE KLAUS DIPL ING ,  KOESTER EBERHARD DIPL PHYS DR ,  BALZ WERNER DIPL CHEM DR ,  GRAU WERNER DIPL CHEM DR

IPC: C08L75/06 ,  C09D5/23 ,  C09D171/00 ,  C09D171/10 ,  C09D175/06 ,  G11B5/70 ,  G11B5/702 ,  G11B5/84 ,  G11B5/842 ,  G11B5/68 ,  B05D3/00 ,  B05D5/12