Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Magnetic imaging
Patent
1983-02-09
1985-03-19
Kittle, John E.
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Magnetic imaging
430 56, 428694, G11B 570, H01F 1002
Patent
active
045060002
ABSTRACT:
A magnetic recording medium having a non-magnetic substrate, a first magnetic layer composed mainly of magnetic powder and binder and formed on the non-magnetic substrate, and a second magnetic layer composed mainly of magnetic powder and binder and formed on the first magnetic layer is disclosed. In this case, the magnetic powder of the first magnetic layer is made of ferro-magnetic metal powder which has a specific surface area of 20 to 40 m.sup.2 /g measured according to BET adsorption method, the first magnetic layer has coercive force H.sub.c1 of 800 to 1500 Oe, residual magnetic flux density of 3000 to 5000 Gausses and a thickness of more than 2.mu., while the magnetic powders of the second magnetic layer is made of ferro-magnetic metal powder which has a specific surface area of 40 to 150 m.sup.2 /g measured according to BET adsorption method, the second magnetic layer has coercive force H.sub.c2 of 1000 to 2500 Oe, residual magnetic flux density of 2000 to 3000 Gausses and a thickness 0.1 to 2.mu., and the coercive forces H.sub.c1 and H.sub.c2 are selected to satisfy H.sub.c1 .ltoreq.H.sub.c2 .
REFERENCES:
patent: 4279945 (1981-07-01), Audran et al.
patent: 4302523 (1981-11-01), Audran et al.
patent: 4309471 (1982-01-01), Suzuki et al.
patent: 4323621 (1982-04-01), Kober et al.
patent: 4410590 (1983-10-01), Kawahara et al.
Kobayashi Kunio
Kubota Isao
Miyao Toshimi
Goodrow John L.
Kittle John E.
Sony Corporation
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