Floppy disk comprising a cellulosic resin with a polar group in a side chain and perromagnetic particles of a specific surface area
AssigneeFuji Photo Film Co., Ltd.
InventorsMikihiko Kato, Hiroshi Hashimoto, Yasushi Endo, Yasuo Nagashima
Life of this patent
Estimating the term…
Abstract
A magnetic recording medium is disclosed, comprising a nonmagnetic support having thereon a magnetic layer comprising mainly ferromagnetic metal particles of a specific surface area and binder resins, wherein at least part of said binder resins is a cellulosic resin having in side chains of the molecules thereof a polar group which is a sulfonic acid group, a metal sulfonate group, a phosphoric acid group, or a metal phosphate group.
Claims1
A floppy disk comprising a nonmagnetic support having thereon a magnetic layer comprising mainly ferromagnetic metal particles and binder resins,
- wherein said ferromagnetic metal particles have a specific surface area of 40 m.sup.2 /g or more and
- an amount of said binder resins is from 5 to 350 parts by weight per 100 parts by weight of the ferromagnetic metal particles, and
- wherein at least part of said binder resins is a cellulosic resin having in side chains of the molecules thereof a polar group which is a sulfonic acid group, a metal sulfonate group, a phosphoric acid group, or a metal phosphate group, and further
- wherein a content of said cellulosic resin is from 25 to 70% by weight based on the binder resins and
- a content of said polar group is from 1.10.sup.-6 to 1.times.10.sup.-3 equivalent per g of the cellulosic resin.
Dependencies are inferred from the claim text.