Magnetic disc having a magnetic layer with a glass transition temperature of at least 75.degree. C. which contains magnetic metal powder of specified pH and surface area
AssigneeFuji Photo Film Co., Ltd.
InventorsYasushi Endo, Mikihiko Kato, Yasuo Nagashima, Toshio Kawamata
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Abstract
A magnetic disc having excellent running durability is disclosed, which comprises a non-magnetic support and a magnetic layer on the non-magnetic support, the layer being composed mainly of a ferromagnetic metal powder and a binder resin, wherein the ferromagnetic metal powder has a pH value of less than 7.0 and a specific surface area as determined by the BET method of at least 40 m.sup.2 /g, and the glass transition temperature of the magnetic layer is at least 75.degree. C.
Claims14
A magnetic disc comprising a non-magnetic support and a magnetic layer on the non-magnetic support, wherein said magnetic layer is comprised of a ferromagnetic metal powder and a binder resin, and wherein said ferromagnetic metal powder has a pH value of less than 7.0 and a specific surface area as determined by the BET method of at least 40 m.sup.2 /g, and said magnetic layer has a glass transition temperature of at least 75.degree. C.
Dependencies are inferred from the claim text.