Patent · US Expired

Process for the preparation of a magnetic dispersion for magnetic recording media and magnetic recording media produced therewith

US6241376A · kind A · utility

4Cited by

4References

14Claims

0Family size

Assignee

Emtec Magnetics GmbH · DE

Inventors

Axel Schunemann · Offenburg, DE
Hans D. Zettler · Havelsee, DE
Peter Nagel · Highlands, US

Key dates

Filing date	Nov 5, 1998
Grant date	Jun 5, 2001
Priority date	—
Expiry date	Nov 5, 2018

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/25
WIPO fieldOther special machines
WIPO sectorMechanical engineering

Abstract

A process for the preparation of high-quality magnetic dispersions having an Hc>120 kA/m, a residual induction Mr/Mm .gtoreq.0.9 and an orientation ratio of about 2.7 achieves, with a self-purging single-shaft blade-type kneading apparatus, very advantageous magnetic values of the magnetic coatings and excellent tape characteristics if at least a) the radial shear gradient in the gap between blade circumference and housing wall is from about 150 to about 1600, in particular from about 500 to about 1400, 1/sec, and b) the circumferential velocity of the kneading blade is from about 20 to about 80, in particular from about 35 to about 60, cm/sec.

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