Novel metal powders and magnetic tapes produced therewith
AssigneeGraham Magnetics Incorporated
InventorsRobert J. Deffeyes, Wesley R. Tyler
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Abstract
Improved processes and products based on the discovery that metal atoms in complex relationship with complexing agents can be used to moderate the formation of organic salt seed crystals which promote an exceptionally well-ordered acicular growth of organometallic salts such as oxalates of the metal. Some acicular, i.e. needle-like, products have particular utility for being reduced to ferromagnetic metal particles which retain a surprisingly large degree of acicularity and possess extraordinarily favorable properties for use in magnetic recording applications.
Claims14
A magnetic recording member of the type utilizing a composition comprising ferromagnetic metal particles in a resin binder and coated on a support member, wherein said metal particles comprise acicular particles consisting of at least 50% by weight of cobalt and characterized by the following parameters:
- ______________________________________ Squareness of at least 0.72 Magnetic Moment of at least 110 Coercivity of at least 500 Increase in Coercivity Between 25.degree. F. and -195.degree. F less than 100% ______________________________________
A metallic powder of small acicular metallic particles comprising at least 50% by weight of cobalt, said particles being characterized by the following characteristics:
- ______________________________________ acicularity :
- 2:1 length :
- less than 2 microns squareness :
- at least 0.72 coercive force :
- at least 500 sigma value :
- at least 110 stable sigma value of :
- at least 77. ______________________________________
Dependencies are inferred from the claim text.