Patent · US Expired

Magnetic recording medium

US4404253A · kind A · utility

25Cited by

6References

3Claims

0Family size

Assignee

Agfa-Gevaert NV · BE

Inventors

Robert Kohler · Temperance, US
Karlchristian Schilffarth · Sauerlach, DE
Heinrich Kober · Starnberg, DE
Burkhard Nippe · Munich, DE

Key dates

Filing date	Feb 25, 1982
Grant date	Sep 13, 1983
Priority date	—
Expiry date	Feb 25, 2002

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/31609
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

Magnetic recording medium using water as dispersion medium. The magnetic layer comprises as binder an aqueous dispersion of polyurethane having functional groups capable of salt formation and a magnetic pigment. The volumetric ratio of magnetic pigment to polyurethane in terms of solids content is in the range of 0.7:1 to 1.4:1.

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