Patent · US Expired

Flexible multi-layer magnetic recording media

US4109046A · kind A · utility

9Cited by

1References

1Claims

0Family size

Assignee

BASF SE

Inventors

Fritz Hammon · Bischofswerda, DE
Manfred Ohlinger · Bischofswerda, DE
Horst Grosselfinger · Bischofswerda, DE
Heinz Stritzinger · Ludwigshafen, DE
Job-Werner Hartmann · Ludwigshafen, DE
Eduard Schoenafinger
Walter Schneider · Thalwil, CH

Key dates

Filing date	Dec 3, 1976
Grant date	Aug 22, 1978
Priority date	—
Expiry date	Dec 3, 1996

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/269
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

Flexible multi-layer magnetic recording media comprising a non-magnetic flexible base and, applied thereto, two superposed magnetizable layers which contain a homogeneous mixture of acicular magnetic chromium dioxide in an organic binder. According to the invention, the magnetizable layer adjacent to the base contains a chromium dioxide having a specific surface area, measured by the BET method, of from 15 to 25 m.sup.2 /g, while the outer magnetic layer contains a chromium dioxide having a specific surface area, measured by the BET method, of from 26 to 35 m.sup.2 /g. Such magnetic recording media are distinguished by uniformly high sensitivity over the entire audible frequency range even if close manufacturing tolerances are not maintained.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.