Patent · US Expired

Spinel-type spherical, black iron oxide particles and process for the producing the same

US5336421A · kind A · utility

51Cited by
3References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 10, 1993
Grant dateAug 9, 1994
Priority date
Expiry dateAug 10, 2013

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC01P2006/60
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Disclosed herein are spinel-type spherical black iron oxide particles containing 1.5 to 17.0 wt % of Zn, and having a specific surface area of 5 to 15 m.sup.2 /g, a magnetization of not less than 70 emu/g in an external magnetic field of 1 kOe and a coercive force (Hc) of not more than the value obtained from the following expression: EQU Hc(Oe)=15+3.times.(specific surface area of the particles). and a process for producing the same.

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