Magnetic recording medium comprising a specified binder resin, specified ferromagnetic metal powder and .alpha.-alumina
US5242752A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 1991 |
| Grant date | Sep 7, 1993 |
| Priority date | — |
| Expiry date | Nov 4, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31935
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium having a support and provided thereon, a magnetic layer containing a ferromagnetic metal powder and a binder is disclosed. The ferromagnetic powder comprises an adsorbed moisture of not less than 1.0 weight % and not more than 2.5 weight % of said ferromagnetic metal powder, a pH value of not less than 9.0 and not morer than 11.5, and a specific surface area of not less than 45 m.sup.2 /g measured by a BET method; and the binder comprises at least one polar group selected from the group consisting of: ##STR1## wherein M represents an atom selected from the group consisting of hydrogen, lithium, sodium, and potassium; and M.sup.1 and M.sup.2 represent atoms of hydrogen, lithium, sodium and potassium, and an alkyl group, provided that M.sup.1 and M.sup.2 may be same with or different from each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.