Method of producing cobalt-modified magnetic particles

Details Method of producing cobalt-modified magnetic particles Method of producing cobalt-modified magnetic particles

1981-11-18

1983-04-05

Cooper, Jack

Coating processes

Magnetic base or coating

252 6256, 427128, C01G 4906

Patent

active

043791832

ABSTRACT:
A method of producing cobalt-modified magnetic particles is provided. The method comprises heating an aqueous suspension of ferric hydroxide at temperatures of 100.degree.-250.degree. C. at an alkaline pH in the presence of a water soluble organic or inorganic compound capable of forming complexes with iron as a growth regulating agent, and preferably also in the presence of .alpha.-ferric oxide seed crystals of minor axes not larger than 0.4 microns in average in amounts of 0.1-25 mole % in terms of the Fe content thereof in relation to the ferric hydroxide, converting the obtained .alpha.-ferric oxide into .gamma.-ferric oxide by reduction thereof followed by oxidation, maintaining an aqueous suspension of the .gamma.-ferric oxide at temperatures of 30.degree.-50.degree. C. at an alkaline pH in the presence of ferrous hydroxide and cobaltous hydroxide in amounts of 0.5-50 mole %, respectively, in relation to the Fe content of the .gamma.-ferric oxide in the suspension for a length of time sufficient to modify the .gamma.-ferric oxide particles.

REFERENCES:
patent: 3252758 (1966-05-01), Hoch et al.
patent: 3262755 (1966-07-01), Steinmetz et al.
patent: 3845198 (1974-10-01), Marcot
patent: 4202871 (1980-05-01), Matsumoto et al.

Affiliated with

Also associated with

Rating

Method of producing cobalt-modified magnetic particles does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of producing cobalt-modified magnetic particles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of producing cobalt-modified magnetic particles will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-565651