公开(公告)号：DE2512450A1

公开(公告)日：1976-10-07

申请号：DE2512450

申请日：1975-03-21

Applicant: BASF AG

Inventor： HACK HOACHIM DIPL ING ,  SCHAEFER DIETER DIPL CHEM DR ,  MOTZ HERBERT DIPL ING DR

IPC: G11B5/708 ,  G11B5/72 ,  H01F10/02

Abstract: Magnetic recording media comprising a base and, applied thereto, at least one firmly adhering magnetic layer based on magnetic particles dispersed in a mixture of organic binders, wherein at least the uppermost magnetic layer additionally contains non-magnetic particles of precipitated silica having a primary particle diameter of from 0.02 to 0.1 mu , a secondary particle diameter of from 2 to 4 mu and a pH of from 5 to 8.

公开(公告)号：DE2753694A1

公开(公告)日：1979-06-07

申请号：DE2753694

申请日：1977-12-02

Applicant: BASF AG

Inventor： MOTZ HERBERT DIPL ING DR ,  LEHNER AUGUST ING GRAD ,  HARTMANN HEINRICH DIPL CHEM DR ,  BACHMANN RUDOLF DIPL CHEM DR ,  HARTMANN HANS-JOERG DIPL ING D ,  FRISCHMANN HARALD DR ,  FALK ROLAND DIPL CHEM DR ,  HACK JOACHIM DIPL CHEM ,  VELIC MILAN DIPL ING DR

IPC: C08G18/66 ,  C09D5/23 ,  G11B5/70 ,  G11B5/702 ,  G11B5/68

Abstract: Magnetic recording media comprising a non-magnetic base and, applied thereto, a firmly adhering magnetic coating based on a finely divided magnetic pigment dispersed in a binder which contains at least 50 percent by weight of a special polyurethane elastomer, namely a thermoplastic polyurethane which is soluble in tetrahydrofuran, is free from isocyanate groups and has been manufactured from (A) 1 mole of a hydroxyl-containing polyester having a molecular weight of from 700 to 2,500, (B) from 0.3 to 3 moles of a linear aliphatic diol of 2 to 10 carbon atoms, (C) from 0.05 to 0.4 mole of a triol of 3 to 10 carbon atoms, and (D) from 1.35 to 4.7 moles of a diisocyanate of 6 to 30 carbon atoms, the amount of NCO groups being approximately equivalent to the amount of OH groups of the sum of components (A) to (C).

公开(公告)号：DE2364879A1

公开(公告)日：1975-07-03

申请号：DE2364879

申请日：1973-12-28

Applicant: BASF AG

Inventor： KOPKE HELMUT ,  HARTMANN HANS-JOERG DIPL ING D ,  MAYER DIETER ,  MOTZ HERBERT DIPL ING DR

IPC: G11B5/708 ,  C08L83/12 ,  C08L101/00 ,  C09D5/23 ,  C09D7/12 ,  G11B5/71 ,  G11B5/72

Abstract: A magnetic recording medium consists of a non-magnetic base, on which the magnetic coating is a layer of a dispersion, containing a lubricant, of a magnetic pigment in a polymeric binder. The lubricant is a block copolymer which contains siloxane units and alkyleneoxy units of 2 to 4 carbon atoms, the alkyleneoxy units being bonded to the polysiloxane radical through a Si-O-C or Si-C group. The use of this lubricant gives a magnetic recording medium which has the advantages of good fluid lubrication and an excellent coefficient of friction which does not vary with time.

公开(公告)号：DE2805405A1

公开(公告)日：1979-08-16

申请号：DE2805405

申请日：1978-02-09

Applicant: BASF AG

Inventor： AUTZEN HORST DIPL CHEM DR ,  MOTZ HERBERT DIPL ING DR ,  RUDOLF PETER DIPL CHEM DR ,  SARNECKI WILHELM DIPL CHEM DR ,  STECK WERNER DIPL CHEM DR ,  VAETH GUENTER

IPC: C01G49/06 ,  G11B5/706 ,  C01G49/02 ,  G11B5/62

Abstract: A process for the manufacture of acicular ferrimagnetic iron oxide by converting acicular iron(III) oxide hydroxide at from 300 DEG to 650 DEG C., by treatment with an organic compound which decomposes in this temperature range in the presence of iron oxide, the iron(III) oxide hydroxide used for the reaction being a lepidocrocite which has been heat-treated at from 300 DEG to 700 DEG C.

公开(公告)号：DE2535448A1

公开(公告)日：1977-02-24

申请号：DE2535448

申请日：1975-08-08

Applicant: BASF AG

Inventor： LOWENBERG GUSTAV DIPL ING ,  HARTMANN HANS-JOERG DIPL ING D ,  SCHAEFER DIETER DIPL CHEM DR ,  MOTZ HERBERT DIPL ING DR ,  JAKUSCH HELMUT DIPL PHYS DR

IPC: G11B5/708 ,  C09D5/23 ,  C09D7/12 ,  C09D131/02 ,  C09D177/00 ,  C09D177/06 ,  G11B5/70 ,  G11B5/702 ,  G11B5/68

公开(公告)号：DE2442762A1

公开(公告)日：1976-03-25

申请号：DE2442762

申请日：1974-09-06

Applicant: BASF AG

Inventor： VAETH GUENTER ,  BACHMANN RUDOLF DIPL CHEM DR ,  HARTMANN HEINRICH DIPL CHEM DR ,  HARTMANN HANS-JOERG DIPL ING D ,  SPOOR HERBERT DIPL CHEM DR ,  UHL KARL DIPL ING DR ,  LEHNER AUGUST ING GRAD ,  MOTZ HERBERT DIPL ING DR

IPC: C08G18/00 ,  C08G18/65 ,  C08G18/66 ,  C09D5/23 ,  G11B5/702 ,  G11B5/68 ,  C09D3/72

公开(公告)号：DE2318910A1

公开(公告)日：1974-10-31

申请号：DE2318910

申请日：1973-04-14

Applicant: BASF AG

Inventor： VAETH GUENTER ,  BACHMANN RUDOLF DIPL CHEM DR ,  SENKPIEL WERNER DIPL CHEM DR ,  HARTMANN HANS-JOERG DIPL ING D ,  FALK ROLAND DIPL CHEM DR ,  MOTZ HERBERT DIPL ING DR

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

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：DE2846623A1

公开(公告)日：1980-05-08

申请号：DE2846623

申请日：1978-10-26

Applicant: BASF AG

Inventor： MOTZ HERBERT DIPL ING DR ,  SCHAEFER DIETER DIPL CHEM DR ,  HUEBNER WERNER DIPL ING ,  MAYER DIETER DR

IPC: G11B5/70 ,  B01F5/06 ,  B01F15/02 ,  B05D5/12 ,  C09D5/23 ,  C09D7/12 ,  G11B5/68 ,  G11B5/84 ,  G11B5/845 ,  B05D3/00

Abstract: A process for the manufacture of magnetic recording media by dispersing a mixture of particulate anisotropic magnetic material and additives in a solution of a polymeric binder in an organic solvent, compressing and then releasing the pressure on the dispersion, thereafter applying a layer of the dispersion to a non-magnetizable base, orienting the anisotropic magnetic material by means of a magnetic field, and drying the coating.

公开(公告)号：DE2617809A1

公开(公告)日：1977-11-03

申请号：DE2617809

申请日：1976-04-23

Applicant: BASF AG

Inventor： SCHOENAFINGER EDUARD DIPL CHEM ,  MOTZ HERBERT DIPL ING DR ,  OHLINGER MANFRED DIPL CHEM DR ,  DEIGNER PAUL DR ,  GRAU WERNER DIPL CHEM DR

IPC: G11B5/712 ,  C09C1/34 ,  C09C3/12 ,  C09D5/23 ,  C09D7/12 ,  G11B5/706 ,  H01F1/11 ,  C04B35/12 ,  C01G37/02 ,  B05D5/12 ,  G11B5/72

Abstract: Chromium dioxide magnetic pigments are stabilized against loss of their magnetic properties by treating them, in aqueous and/or alcoholic suspension, with a block copolymer consisting of siloxane units and alkyleneoxy units of 2 to 4 carbon atoms, the alkyleneoxy units being bonded to the polysiloxane radical by a Si-O-C or Si-C group, in an amount of from 1 to 40% by weight based on the chromium dioxide, after which the latter is separated off and dried at from 50 DEG to 200 DEG C. The stabilized chromium dioxide magnetic pigments may be used for the manufacture of magnetic recording media exhibiting improved stability of the magnetic properties under adverse climatic conditions.

公开(公告)号：DE2459541A1

公开(公告)日：1976-07-01

申请号：DE2459541

申请日：1974-12-17

Applicant: BASF AG

Inventor： KOESTER EBERHARD DIPL PHYS DR ,  DEIGNER PAUL DR ,  FALK ROLAND DIPL CHEM DR ,  UHL KARL DIPL ING DR ,  SCHAEFER DIETER DIPL CHEM DR ,  MAYER DIETER DR ,  MOTZ HERBERT DIPL ING DR ,  FELLEISEN PETER DIPL ING

IPC: B05C11/08 ,  B05D1/40 ,  G11B5/842 ,  G11B5/84 ,  B05D5/12

Abstract: The invention relates to an improved process for the manufacture of magnetic discs carrying very thin magnetic layers, by applying a fluid dispersion of magnetic materials in a binder mixture to rigid base discs by the spin-coating process. Above the side of the base disc which is to be provided with the magnetic layer, there are arranged means which produce an aerodynamic boundary layer above the discs during rotation of the latter. This avoids the formation of surface irregularities and of coating streaks during production of the layer by spin-coating.