公开(公告)号：DE2236593A1

公开(公告)日：1974-03-28

申请号：DE2236593

申请日：1972-07-26

Applicant: BASF AG

Inventor： SCHNELL GEORG DR ,  HAMMON FRITZ ,  REIMER KARL-JUERGEN

IPC: G11B15/093 ,  G11B5/02 ,  G11B15/02 ,  G11B15/06

Abstract: This invention concerns methods and devices for switching a tape-recorder or cassette tape-recorder and especially recorders on which tapes with different magnetic coatings can be used. According to the invention, at least one section along the magnetic tape which has a much higher electric resistance than the magnetic coating is used in conjunction with arrangements of simple layout and in advantageous manner to monitor the resistance of the tape either continuously or sporadically, and at least one predetermined switching state of the recorder is allocated to each different resistance value. This ensures reliable switching of any such states as "machine on", "machine off" or "iron oxide (chromium dioxide) tape" bias, without any other special changes at the magnetic tape or at the cassette.

公开(公告)号：DE1522975A1

公开(公告)日：1969-10-30

申请号：DE1522975

申请日：1966-07-09

Applicant: BASF AG

Inventor： HAMMON FRITZ ,  ERNST BELGER DIPL-PHYS

IPC: G11B5/56

公开(公告)号：DE3164244D1

公开(公告)日：1984-07-26

申请号：DE3164244

申请日：1981-01-13

Applicant: BASF AG

Inventor： HAMMON FRITZ

IPC: G01B11/24 ,  B65H26/00 ,  G01B11/30 ,  G01N21/88 ,  G01N21/89 ,  G01N21/892 ,  G07D7/00 ,  G07D7/181 ,  G07D7/20

Abstract: The surface character of flexible materials is examined by means of interference fields which are formed by reflection of light beams from a reflecting reference surface and from the adjoining surface to be examined, and subsequent super-position of the partial beams thereby formed. The interference field which corresponds to the surface profile standing out from the reference surface is utilized to determine the length and height of the surface profile, with the aid of the interference band spacings and the wavelength of the incident light.

公开(公告)号：GB2000295B

公开(公告)日：1982-03-10

申请号：GB7826625

申请日：1978-06-09

Applicant: BASF AG

Inventor： HAMMON FRITZ ,  OHLINGER MANFRED ,  HARTMANN JOB-WERNER

IPC: G01R33/00 ,  G01N27/72 ,  G01N27/74 ,  G01R33/12 ,  G11B5/84 ,  G11B5/845

Abstract: In order to determine the homogeneity of a magnetic dispersion, part of the dispersion is conducted through a measuring cell prior to its application to a base, the size, number and type of those regions of the magnetic dispersion which interfere with the homogeneity being determined with the aid of magnetic measurements. The measuring cell contains a magnetic head, a magnetic dispersion is made to flow in a stream of constant cross section past the air gap of the magnetic head, and a magnetic field at least partially penetrating the magnetic dispersion is produced. From the characteristics of the amplified output voltage of the magnetic head the various parameters of the inhomogeneities in the magnetic dispersion can then be ascertained.

公开(公告)号：DE2556188A1

公开(公告)日：1977-06-23

申请号：DE2556188

申请日：1975-12-13

Applicant: BASF AG

Inventor： HAMMON FRITZ ,  OHLINGER MANFRED DIPL CHEM DR ,  GROSSELFINGER HORST DIPL ING ,  STRITZINGER HEINZ DIPL ING ,  HARTMANN JOB-WERNER DIPL CHEM

IPC: C09D5/23 ,  C09D7/12 ,  G11B5/706 ,  G11B5/716 ,  G11B5/68 ,  B05D5/12

公开(公告)号：DE2213245A1

公开(公告)日：1973-09-20

申请号：DE2213245

申请日：1972-03-18

Applicant: BASF AG

Inventor： HAMMON FRITZ ,  HUEBNER DIETMAR ,  MAERTHESHEIMER ROLF

IPC: B65D83/08 ,  B65D85/00

公开(公告)号：DE2002318A1

公开(公告)日：1971-07-29

申请号：DE2002318

申请日：1970-01-20

Applicant: BASF AG

Inventor： SCHNELL GEORG DR ,  STRITZINGER HEINZ DIPL-ING ,  HAMMON FRITZ ,  HOPP MANFRED DR ,  VAETH GUENTER ,  GRAU WERNER DR

IPC: G11B5/73 ,  G11B5/70 ,  G11B5/735 ,  G11B5/74 ,  G11B5/78

公开(公告)号：DE1009831B

公开(公告)日：1957-06-06

申请号：DEA0022246

申请日：1955-03-11

Applicant: BASF AG

Inventor： HAMMON FRITZ ,  JARCZYK DIPL-ING FRANZ-CHRISTI

IPC: G01P3/42

公开(公告)号：DE2653723A1

公开(公告)日：1978-06-01

申请号：DE2653723

申请日：1976-11-26

Applicant: BASF AG

Inventor： HARTMANN JOB-WERNER DIPL CHEM ,  OHLINGER MANFRED DIPL CHEM DR ,  HAMMON FRITZ ,  WETTSTEIN EUGEN

IPC: G11B5/708 ,  G11B5/68 ,  B05D5/12 ,  B05D7/26 ,  C08K9/06

Abstract: A magnetic recording material is prepd. by appln. of is not 1 layer of a dispersion onto a non-magnetic carrier and converting the layer into a hard magnetic layer of predetermined thickness. The dispersion contains (a) a finely divided magnetic powder and (b) dispersed SiO2 with particle dimensions of ratio 6-8:2.5-4:1, and with average particle size corresp. to the thickness of the magnetic layer, in (c) a soln. of an organic polymeric binder in an organic solvent. The dispersion may also contain the usual additives. The material has high mechanical strength, and shows no increase in friction between the magnetic layer and the magnetic head at high temp. and humidity. Deposition of material on the head is avoided.

公开(公告)号：DE2254810A1

公开(公告)日：1974-05-22

申请号：DE2254810

申请日：1972-11-09

Applicant: BASF AG

Inventor： SCHNELL GEORG DR ,  HAMMON FRITZ ,  OHLINGER MANFRED DR

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

Abstract: The invention relates to a process for improving the magnetic properties, especially the remanent magnetization, of gamma-iron(III) oxide which can be used advantageously as the magnetic component in magnetic recording media exhibiting reduced print-through. For this purpose, a gamma-iron(III) oxide manufactured according to known processes is heated at temperatures of from 400 DEG to 700 DEG C., the magnetic pigment having basic compounds on the crystal surface during this heat treatment and retaining a pH value above 8 until heating is over. Gamma-iron(III) oxide magnetic pigments treated in this way are particularly suitable for the manufacture of low-noise magnetic recording media with high remanent magnetization and particularly low print-through.