Magnetic recording tapes with two-layered magnetic coating
US4075384A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1976 |
| Grant date | Feb 21, 1978 |
| Priority date | — |
| Expiry date | Oct 21, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/257
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording tape of improved properties comprising a non-magnetic support and a two-layered magnetic coating composed of a ferromagnetic powder and a binder and formed on one surface of the support, wherein the lower magnetic layer has a coercive force of about 250 to about 300 Oe, a residual magnetic flux density of at least about 1,500 Gauss and a dry thickness of at least about 2.5 .mu.m, and the upper magnetic layer has a coercive force of about 350 to about 400 Oe, a residual magnetic flux density of not more than about 1,500 Gauss and a dry thickness of about 2.0 to 3.0 .mu.m, the ferromagnetic powder in the upper magnetic layer having an APP value of not more than 1.0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.