Patent · US Expired

Method of preparing a magnetic recording medium

US5069931A · kind A · utility

2Cited by

0References

11Claims

0Family size

Assignee

BASF Magnetics GmbH · DE

Inventors

Johannes Gerum · Germering, DE
Horst Schulz · Friedrichshafen, DE
Jurgen Sauter · Mannheim, DE

Key dates

Filing date	Apr 16, 1991
Grant date	Dec 3, 1991
Priority date	—
Expiry date	Apr 16, 2011

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10S428/90
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

A magnetic recording medium consisting of a flexible layer support and a magnetic layer consisting predominantly of magnetic particles finely divided in a binder and nonmagnetic additives applied to the layer support is obtained with improved orientation of the magnetic pigments by adding a dispersion stabilizing component to the magnetic dispersion at a uniform rate over the whole period of dispersion. Highly purified lecithin or a mixed ester of a polyethoxy phosphate ester or ethylene diaminodistearate, a polyurethane resin containing sulphonate groups or a vinyl chloride/vinyl alcohol copolymer is preferred as stabilizing additive.

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