Patent · US Expired

Magnetic pigments with improved orientability and a process for their production

US4014710A · kind A · utility

8Cited by

3References

10Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Peter Woditsch · Krefeld, DE
Franz Hund · Krefeld, DE
Gunter Buxbaum · Krefeld, DE
Volker Hahnkamm · Krefeld, DE
Ingo Pflugmacher · Meerbusch, DE

Key dates

Filing date	Jul 18, 1974
Grant date	Mar 29, 1977
Priority date	—
Expiry date	Jul 18, 1994

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01P2004/10
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

An acicular, magnetic iron oxide pigment containing about 0.05 to 5% by weight of an organo silicon compound is produced by treating iron oxide hydroxide seeds either dry or in suspension with an organo silicon compound. Preferred organo silicon compounds comprise polymethylphenylsiloxane, polydimethylsiloxane and polydiphenylsiloxane. Trivalent metal ions may subsequently be deposited. The resulting pigments show only minimal losses of coercive force during processing into magnetic tapes.

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