The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 19, 1985
Filed:
May. 23, 1984
Hiroshi Ogawa, Kanagawa, JP;
Chiaki Mizuno, Kanagawa, JP;
Kouichi Masaki, Kanagawa, JP;
Masaaki Suzuki, Kanagawa, JP;
Yasuo Tamai, Kanagawa, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A magnetic recording medium comprising a nonmagnetic base having formed thereon a magnetic layer containing a fine particulate ferromagnetic material dispersed in a binder is disclosed. The ferromagnetic material is a mixture of two fine ferromagnetic powders (a) and (b) in a weight ratio of from 90/10 to 30/70. The powder (a) comprises .gamma.-Fe.sub.2 O.sub.3 particles having a coercivity (Hc) of 330 to 390 Oe and a saturation magnetization (.sigma.s) of 68 to 80 emu/g at a maximum magnetizing force (Hm) of 5 KOe, and a specific surface area of 18 to 25 m.sup.2 /g, and powder (b) comprises .gamma.-Fe.sub.2 O.sub.3 particles having a coercivity (Hc) of 400 to 450 Oe and a saturation magnetization (.sigma.s) of 65 to 78 emu/g at a maximum magnetizing force (Hm) of 5 KOe, and a specific surface area of 22 to 30 m.sup.2 /g. The tape has the ability to clearly and faithfully reproduce high fidelity sound.