Metallic iron particles for magnetic recording
AssigneePfizer Inc.
InventorLouis J. Dizikes
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Abstract
In the process for preparing a magnetically stable powder comprising the steps of reducing an iron oxide precursor with a gaseous reduction agent and stabilizing the metallic powder thus produced, the improvement which comprises coating said iron oxide precursor with an antimony compound at a level of up to about 7 weight percent antimony based on the weight of the iron oxide content of the precursor and precipitating tin hydroxides or oxyhydroxides at a level of from about 0.5 to about 8.0 weight percent tin based on the weight of the iron oxide content of the precursor onto the antimony coated iron oxide precursor prior to said reduction.
Claims10
In the process for preparing a magnetically stable powder comprising the steps of
- A. Reducing an iron oxide precursor selected from the group consisting of an iron oxide, an iron oxide hydrate, a modified iron oxide or a modified iron oxide hydrate with a gaseous reduction agent;
- and
- B. Stabilizing the metallic powder thus produced, the improvement which comprises:
- coating said iron oxide precursor with an antimony compound at a level of up to about 7 weight percent antimony based on the weight of the iron oxide content of said precursor and precipitating tin hydroxides or oxyhydroxides at a level of from about 0.5 to about 8.0 weight percent tin based on the weight of the iron oxide content of said precursor onto the antimony coated iron oxide precursor prior to said reduction.
Dependencies are inferred from the claim text.