公开(公告)号：DE2749757A1

公开(公告)日：1979-05-10

申请号：DE2749757

申请日：1977-11-07

Applicant: BASF AG

Inventor： VAETH GUENTER ,  OHLINGER MANFRED DIPL CHEM DR ,  HARTMANN HANS-JOERG DIPL ING D ,  VELIC MILAN DIPL ING DR ,  MUENZNER WULF DIPL ING DR

IPC: G11B5/706 ,  G11B5/712 ,  G11B5/68 ,  C09C1/34

Abstract: Magnetic recording material has a non-magnetic substrate with a firmly adhering magnetic coating of acicular ferromagnetic CrO2 finely dispersed in an organic polymeric binder and additives. Before incorporation in the binder, the CrO2 is suspended in an aq. soln. of the Fe(II) salt and a reducing agent, the Fe)II) ions are pptd. on the CrO2 as Fe(OH)2 by addn. of water-soluble hydroxide or carbonate and this Fe(OH)2 is then converted to an oxide deposit contg. Fe(III) by treatment with a gaseous or water-miscible oxidant. The oxide deposit pref. consists of goethite and/or lepidocrocite or magnetite. The Fe oxide deposit improves the stability and mechanical properties of the CrO2 under unfavourable climatic conditions.

公开(公告)号：DE3134894A1

公开(公告)日：1983-03-10

申请号：DE3134894

申请日：1981-09-03

Applicant: BASF AG

Inventor： ROOS ROLAND ,  SCHOMANN KLAUS DIETER DIPL PHY ,  MUENZNER WULF DIPL ING DR

IPC: G11B15/60 ,  G11B23/04 ,  G11B23/087 ,  G11B23/50 ,  H05F3/00 ,  G11B15/28 ,  G11B25/06 ,  G11B5/72 ,  H04N5/782

Abstract: A tape guide system wherein a magnetic tape having different resistivities on its back and front travels in contact with guide elements, the members of these elements which are in contact with the tape being matched to the relevant face of the tape in respect of surface resistivity and/or of charge affinity. The members contacting the front of the magnetic tape accordingly consist of a conductive or low-insulation material and the members contacting the back of the tape consist of a high-insulation material. In alternative embodiments, the contact members can consist of a material of low conductivity, or of a plastic with an added conductive material. The novel guide system can be used in any type of high-speed magnetic tape transport mechanism. The invention also concerns the tape guide elements per se, and magnetic tape cassettes employing the tape guide system.

公开(公告)号：DE2500546A1

公开(公告)日：1976-07-15

申请号：DE2500546

申请日：1975-01-08

Applicant: BASF AG

Inventor： ROLLER HERMANN ,  WOLLNIK MANFRED DIPL ING DR ,  HARTMANN HANS-JOERG DIPL ING D ,  GUTERMANN WINFRIED ,  MUENZNER WULF DIPL ING DR

IPC: C09D5/23 ,  G11B5/735 ,  G11B5/68 ,  B05D5/12 ,  H01F10/02

Abstract: In the prepn. of a flexible layered tape, the magnetic layer is prepd. from a dispersion of magnetisable particles in a soln. in an organic solvent of a polymeric binder. This dispersion is applied to one side of a flexible synthetic tape provided on the other side with an adhesive intermediate layer (Z) based on a vinylidenechloride copolymer, contg. 70% vinylidene chloride, and a back layer (R) containing polymer bound carbon black. A dispersion is prepd. of 15-30 wt. % carbon black and 2-8 wt. % of a de-lustering agent in a binder of 62-83 wt. % elastomeric, isocyanate gp. free polyesterurethane, an epoxide resin (ratio 4:1) and non volatile polyisocyanates. The latter are present in an excess of 100-400 equiv. % over the quantity of isocyanate groups needed for crosslinking of total reactive groups in the layer R. This dispersion of carbon black is applied to the layer Z which contains 1-15 wt. %, relative to solids content of the copolymer of Di-n-octyltin-bis (2-ethyl-hexyl thioglycolate) (1). Esp. useful for video tapes.

公开(公告)号：DE2803914A1

公开(公告)日：1979-08-02

申请号：DE2803914

申请日：1978-01-30

Applicant: BASF AG

Inventor： SCHOETTLE KLAUS DIPL ING ,  MUENZNER WULF DIPL ING DR ,  LECHNER HILMAR DIPL ING ,  WOEPPEL DIETER ,  GLINIORZ LOTHAR

IPC: B24B7/13 ,  B24B21/04 ,  B24B39/06 ,  B24B55/12 ,  B29C59/02 ,  G11B5/84 ,  G11B23/50

Abstract: A process and apparatus for the treatment of the recording surface of magnetic recording media using consecutively arranged units for burnishing, cleaning and calendering the web of plastics film provided with a magnetic coating. The process and apparatus of the invention are particularly suitable for the manufacture of magnetic tapes for the recording and playback of video signals.

公开(公告)号：DE2653345A1

公开(公告)日：1978-06-01

申请号：DE2653345

申请日：1976-11-24

Applicant: BASF AG

Inventor： MUENZNER WULF DIPL ING DR ,  SCHOETTLE KLAUS DIPL ING

IPC: C21C1/10 ,  B22D1/00 ,  B22D27/20 ,  G11B5/008 ,  G11B5/48 ,  G11B5/55 ,  G11B27/029

Abstract: The magnetic record/replay/erase head comprises a three unit block (5) mounted on a bearing spindle (6), the tip of which glides over a disc with a spiral shoulder (7). Rotation of the bearing spindle causes the height of the head to be modified. The front face of the head has three pick-up units (8, 9, 10)which may be used in conjunction with an array of parallel magnetic tracks so that read/write/erase may be carried out on audio or video record tracks at the same time. The ability to pick-up and record enables a video tape to have audio signals superimposed on it.