Patent · US Expired

Magnetic recording medium

US5455104A · kind A · utility

15Cited by
7References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 30, 1993
Grant dateOct 3, 1995
Priority date
Expiry dateNov 30, 2013

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/257
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

The present invention provides a magnetic recording medium comprising a support, lower magnetic layer comprising ferromagnetic powder and nonmagnetic powder dispersed in a binder and an upper magnetic layer which contains ferromagnetic powder dispersed in a binder. The lower layer has a coercive force of not less than 200 Oe, a saturation magnetic flux density in the range of 5-1000 gauss and non magnetic particles with a specific gravity of not less than 2.5. The ferromagnetic powder of the upper layer is a ferromagnetic metal powder containing Fe and Al, and the ratio of non magnetic powder to magnetic powder in the lower magnetic layer is from 50/50 to 99/1.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.