Coating processes – Magnetic base or coating
Reexamination Certificate
2005-09-06
2005-09-06
Le, H. Thi (Department: 1773)
Coating processes
Magnetic base or coating
C427S215000
Reexamination Certificate
active
06939575
ABSTRACT:
A ferromagnetic metal powder having an average long axis length of from 30 to 65 nm, a crystallite size of from 80 to 130 angstroms, a saturation magnetization (σs) of from 75 to 130 A·m2/kg, and an average oxide layer thickness of from 1.5 to 2.5 nm; a method of producing a ferromagnetic metal powder comprising: reducing the oxide of a ferromagnetic metal element to obtain the ferromagnetic metal powder, subjecting the ferromagnetic metal powder to gradual oxidation treatment to make as 120 to 150 A·m2/kg, adhering at least one element selected from Al, Y, lanthanoid, Zr and W to the ferromagnetic metal powder in water, performing heat treatment, and again performing gradual oxidation treatment; and a magnetic recording medium comprising a support having provided thereon a magnetic layer mainly comprising a ferromagnetic metal powder and a binder, wherein the magnetic layer containing the ferromagnetic metal powder has a thickness of from 0.04 to 0.25 μm, and demagnetization after storage at 60° C. 90% RH for one week of 10% or less.
REFERENCES:
patent: 3958068 (1976-05-01), Umeki et al.
patent: 4125474 (1978-11-01), Dezawa et al.
patent: 4155748 (1979-05-01), Steck et al.
patent: 4253886 (1981-03-01), Aonuma et al.
patent: 4431712 (1984-02-01), Matsufuji et al.
patent: 4475946 (1984-10-01), Matsufuji et al.
patent: 4604296 (1986-08-01), Aonuma et al.
patent: 5399278 (1995-03-01), Yamashita et al.
patent: 5512194 (1996-04-01), Ogasawara et al.
patent: 5580399 (1996-12-01), Tamai et al.
patent: 5735969 (1998-04-01), Lown et al.
patent: 5770302 (1998-06-01), Masaki
patent: 6149989 (2000-11-01), Araki et al.
patent: 6607807 (2003-08-01), Zinbo et al.
patent: 6638599 (2003-10-01), Masaki et al.
patent: 6689455 (2004-02-01), Masaki
patent: 6753084 (2004-06-01), Maekawa et al.
patent: 6-68829 (1994-08-01), None
LandOfFree
Ferromagnetic metal powder, producing method of the same,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ferromagnetic metal powder, producing method of the same,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ferromagnetic metal powder, producing method of the same,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3436347