Patent · US Expired

Process for preparing modified chromium dioxide

US5378383A · kind A · utility

4Cited by

2References

1Claims

0Family size

Assignee

BASF Magnetics GmbH · DE

Inventors

Harald Jachow · Worms, DE
Ekkehard Schwab · Neustadt, DE
Reinhard Koerner · Bischofswerda, DE
Norbert Mueller · Ostseebad Nienhagen, DE
Rudi Lehnert · Ludwigshafen, DE
Manfred Ohlinger · Bischofswerda, DE
Helmut Auweter · Schifferstadt, DE
Helmut Jakusch · Bischofswerda, DE
Ronald J. Veitch · Frankenthal (Pfalz), DE
Michael Bobrich · Haßloch, DE

Key dates

Filing date	Aug 20, 1993
Grant date	Jan 3, 1995
Priority date	—
Expiry date	Aug 20, 2013

Classification

Technology area (CPC G)Physics
CPC primaryG11B5/70636
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

A magnetic recording medium comprising a nonmagnetic substrate and at least one magnetic layer applied thereon and containing an acicular chromium dioxide uniformly distributed in a polymeric binder and additives and having a coercive force of at least 60 kA/m, a mean particle length of the chromium dioxide of less than 300 nm, whose factor HD according to the formula ##EQU1## where KT is the coercive force of the magnetic layer in [kA/m], measured in an external field of 380 kA/m, L is the mean particle length and .DELTA.L is the range of the particle size distribution, determined from the numerical distribution of the particle length, both measured in [nm], is greater than 1.85, and a process for the preparation of this chromium dioxide.

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