Title:
METALLIC MAGNETIC POWDER, PROCESS FOR PRODUCING SAME, MAGNETIC COATING COMPOSITION, AND MAGNETIC RECORDING MEDIUM
Document Type and Number:
WIPO Patent Application WO/2011/125914
Kind Code:
A1
Abstract:
Provided are: a metallic magnetic powder which comprises metallic magnetic particles reduced in particle volume and which, when mixed with organic substances including resins, has improved affinity therefor and in which the metallic magnetic particles have improved dispersibility in organic substances including resins; a process for producing the metallic magnetic powder; a coating composition including the metallic magnetic powder; and a magnetic recording medium. The process is for producing a metallic magnetic powder comprising particles which have a metallic magnetic phase comprising a ferromagnetic element as the main component and which contain as a nonmagnetic component at least one element selected from rare-earth elements including Y and from Al and Si. The process includes: a step in which a metallic magnetic powder which has not undergone a treatment for diminishing the nonmagnetic component is treated with a reducing agent in a liquid containing a complexing agent capable of forming a complex with the nonmagnetic component, thereby causing the nonmagnetic component contained in the particles to dissolve away in the liquid; and a step in which an oxide film is formed, within the liquid, on the particles from which the nonmagnetic component has been released into the liquid, without drying the particles.
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Inventors:
OMOTO HIROHISA (JP)
KIKUCHI TAKAYUKI (JP)
UEYAMA TOSHIHIKO (JP)
KIKUCHI TAKAYUKI (JP)
UEYAMA TOSHIHIKO (JP)
Application Number:
PCT/JP2011/058358
Publication Date:
October 13, 2011
Filing Date:
March 31, 2011
Export Citation:
Assignee:
DOWA ELECTRONICS MATERIALS CO (JP)
OMOTO HIROHISA (JP)
KIKUCHI TAKAYUKI (JP)
UEYAMA TOSHIHIKO (JP)
OMOTO HIROHISA (JP)
KIKUCHI TAKAYUKI (JP)
UEYAMA TOSHIHIKO (JP)
International Classes:
G11B5/842; B22F1/16; G11B5/712; H01F1/06
Domestic Patent References:
| WO2010016154A1 | 2010-02-11 |
Foreign References:
| JP2007294841A | 2007-11-08 | |||
| JPS5630707A | 1981-03-27 | |||
| JP2003263720A | 2003-09-19 | |||
| JP2007294841A | 2007-11-08 | |||
| JP2007263860A | 2007-10-11 |
Other References:
See also references of EP 2555194A4
Attorney, Agent or Firm:
ANIYA Setuo et al. (JP)
Ani store Setsuo (JP)
Ani store Setsuo (JP)
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Claims: