Ferromagnetic metal particles, consisting essentially of iron and carrying a surface coating, and their production
AssigneeBASF SE
InventorsWerner Steck, Hermann Roller, Wilhelm Sarnecki, Werner Balz
Life of this patent
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Abstract
Ferromagnetic metal particles, consisting essentially of iron and comprising a core, containing not less than 85% by weight of metallic iron, and an iron oxide plus chromium oxide surface layer surrounding this core, which layer additionally contains one or more elements selected from the group comprising zinc, phosphorus in the form of phosphate, aluminum, calcium, strontium, barium, cadmium, lead, cobalt and nickel in a total amount of not more than 9.5% by weight, based on the total amount of the metal particles, and a process for the production of such particles.
Claims4
Ferromagnetic metal particles, consisting essentially of iron and comprising a core, containing not less than 85% by weight of metallic iron, and an iron oxide plus chromium oxide surface layer surrounding this core, wherein in the surface layer contains, in addition to iron, oxygen and from 1 to 9% by weight of chromium, based on the total amount of the metal particles, at least one element selected from the group comprising zinc, phosphorus in the form of phosphate, aluminum, calcium, strontium, barium, cadmium, lead, cobalt and nickel, in a total amount of not more than 9.5% by weight, based on the total amount of the metal particles.
Dependencies are inferred from the claim text.