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US 4,541,973 AGranted
Production of ferrimagnetic spinel fibers
AssigneeCelanese Corporation
InventorRichard M. Arons
Life of this patent
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Abstract
This invention provides a spinning process for the preparation of ferrimagnetic spinel fibers composed of crystallites corresponding to the formula: M.sub.1 Fe.sub.2 O.sub.4 where M is manganese, iron, cobalt, nickel, copper, zinc, cadmium, magnesium, barium, strontium, or any combination thereof.
Claims7
A process for the production of ferrimagnetic spinel fibers which comprises (1) forming a spinning composition comprising a fluid organic polymer medium having dispersed therein particulate ferrite with an average particle size less than about 1000 angstroms, wherein the ferrite is a spinel corresponding to the formula:
- M.sub.1 Fe.sub.2 O.sub.4
- where M is manganese, iron, cobalt, nickel, copper, zinc, cadmium, magnesium, barium, strontium, or any combination thereof;
- (2) spinning the composition into a coagulating medium to form solid fibers;
- and (3) stabilizing the fibers by chemical treatment with a reactive free radical-forming crosslinking agent and pyrolyzing the fibers at a temperature between about 800.degree.-2500.degree. C. in the presence of molecular oxygen to form ferrimagnetic M.sub.1 Fe.sub.2 O.sub.4 spinel fibers.
1 more element
Dependencies are inferred from the claim text.