Patent · US Expired

Stabilized magnetic pigments

US4689086A · kind A · utility

9Cited by

8References

4Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Rolf Naumann · Krefeld, DE
Jakob Rademachers · Krefeld, DE
Gunter Buxbaum · Krefeld, DE
Fritz Rodi · Moers, DE
Karl Waid · Bornheim, DE

Key dates

Filing date	Oct 24, 1985
Grant date	Aug 25, 1987
Priority date	—
Expiry date	Oct 24, 2005

Classification

Technology area (CPC H)Electricity
CPC primaryH01F1/061
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

Sensitive magnetic pigment particles enclosed in about 0.1 to 5% by weight of a polymeric material thereby preserving the pigment magnetic properties. Advantageously, the polymer, which serves as a packing, is at least one member selected from the group consisting of polycarbonates, polyacrylates, polymethacrylates, polyesters, polyethers, polyurethanes, polyvinyl compounds, polyvinylidene compounds and cellulose compounds. These are compatible with the matrices used to make magnetic tapes.

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