Multilayer magnetic recording medium

Patent 4259392 Issued on March 31, 1981. Estimated Expiration Date:

June 16, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3740266

Magnetic recording tapes with two-layered magnetic coating Patent #: 4075384
Issued on: 02/21/1978
Inventor: Suzuki , et al.

Inventor

Suzuki, Masaaki

Assignee

Fuji Photo Film Co., Ltd.

Application

No. 05/916430 filed on 06/16/1978

US Classes:

428/212, Including components having same physical characteristic in differing degree360/135, Disk360/136, Drum427/131, Applying superposed diverse coating or coating a coated base428/336, 1 mil or less428/339, Including synthetic resin or polymer layer or component428/839.3, Chemically specified magnetic material428/900MAGNETIC FEATURE

Examiners

Primary: Silverman, Stanley S.

Attorney, Agent or Firm

Sughrue, Rothwell, Mion, Zinn and Macpeak

International Class

G11B 5/716 (20060101)

Foreign Application Priority Data

1977-06-16 JP

Abstract

A magnetic recording tape comprising a non-magnetic support having thereon a dual layer magnetic recording coating comprising ferromagnetic particles dispersed in a binder, wherein the fine ferromagnetic particles of the outer layer are a mixture of two or more kinds of fine ferromagnetic particles having two or more peaks in the coercive force distribution and said particles containing at least one kind of fine ferromagnetic alloy particles and the fine ferromagnetic particles of the inner layer being ferromagnetic iron oxide particles having peaks in the coercive force distribution lower than the minimum peaks in the coercive force distribution of the ferromagnetic particles of the outer layer, with the thickness of the outer layer not being greater than the thickness of the inner layer.