Title:
MANUFACTURE OF COBALT-CONTAINED IRON OXIDE MAGNETIC POWDER
Document Type and Number:
Japanese Patent JPH01194306
Kind Code:
A
Abstract:
PURPOSE:To ensure coercive force while improving a delete characteristic by jointly using low temperature treatment in a cobalt salt-contained alkaline solution and heating agitation in a neutral solution when coating iron oxide magnetic powder with a cobalt compound. CONSTITUTION:Dispersion liquid containing cobalt salt and alkaline more than an equivalent is made to react with iron oxide magnetic powder while holding the temperature of 10-50 deg.C and the surface of iron oxide magnetic powder is coated with a cobalt compound. After coating this oxide, washing is performed to neutralize the dispersion liquid, next, this neutral dispersion liquid is agitated at a temperature lower than its boiling point for dehydration and drying. Then, cobalt-containing iron oxide magnetic powder having high coercive force besides being excellent in a deletion characteristic is manufactured so as to obtain a magnetic recording medium capable of high density recording.
Inventors:
ARIZAKA YUICHI
Application Number:
JP1875088A
Publication Date:
August 04, 1989
Filing Date:
January 29, 1988
Export Citation:
Assignee:
SONY CORP
International Classes:
C01G49/02; C09D5/23; C09D7/12; G11B5/712; H01F1/11; (IPC1-7): C01G49/02; G11B5/712; H01F1/11
Domestic Patent References:
| JPS5888122A | 1983-05-26 | |||
| JPS6236024A | 1987-02-17 | |||
| JP62333625A | ||||
| JPS5556016A | 1980-04-24 | |||
| JPS5556019A | 1980-04-24 |
Attorney, Agent or Firm:
Akira Koike (2 outside)
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