Patent · US Expired

Magnetic metal and alloy pigments

US4325739A · kind A · utility

8Cited by

8References

9Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Hans-Peter Biermann · Krefeld, DE
Helmut Steinberger · Leverkusen, DE
Artur Botta · Krefeld, DE
Rolf Naumann · Krefeld, DE
Lutz Leitner · Krefeld, DE
Heinrich Heine · Krefeld, DE

Key dates

Filing date	Nov 5, 1980
Grant date	Apr 20, 1982
Priority date	—
Expiry date	Nov 5, 2000

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/2995
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A pigment of a magnetic metal or alloy thereof carrying, in about 0.2 to 30% of the weight of the metal or alloy, a coating of at least one member selected from the group consisting of an ortho-silicic acid ester, a hydrolyzate thereof and a condensation product thereof. Optionally it also carries a corrosion inhibitor. The coated pigment is produced by suspension of the untreated pigment in a liquid medium containing the ortho-silicic acid ester or derivative thereof, and optionally the corrosion inhibitor, followed by separation and drying at 50.degree. to 250.degree. C. The resulting pigment is non-pyrophoric and of high performance properties suitable for use in magnetic recording media.

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