Magnetic recording medium comprising ferromagnetic powder and polar group containing ginder resins having different glass transition temperatures
US5153079A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1991 |
| Grant date | Oct 6, 1992 |
| Priority date | — |
| Expiry date | Dec 6, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31609
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium is disclosed which comprises a non-magnetic support and a magnetic layer comprising a ferromagnetic powder having a specific surface area of not less than 55 m.sup.2 /g and at least two kinds of resins each containing repetitive units having a polar group selected from the group consisting of a --SO.sub.3 M group, a --OSO.sub.3 M group, a --COOM group and a --PO(OM').sub.2 group, wherein M is a hydrogen atom or an alkali metal atom, and M' is a hydrogen atom, an alkali metal atom or an alkyl group, and the glass transition points of said two resins are different not less than 60.degree. C. from each other. The recording medium is improved in the dispersibility of the ferromagnetic powder in the magnetic layer and has a satisfactory surface smoothness, high electromagnetic conversion characteristics and a satisfactory running durability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.