Magnetic recording medium
US7005203B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 2003 |
| Grant date | Feb 28, 2006 |
| Priority date | — |
| Expiry date | Oct 27, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/7023
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Provided is a magnetic recording medium that exhibits excellent electromagnetic characteristics especially in recording and reproducing systems using an MR head, as well as has excellent long-term preservation property. The magnetic recording medium comprises a lower layer comprising a nonmagnetic powder or a ferromagnetic powder and a binder and at least one magnetic layer thereover comprising a ferromagnetic powder and a binder on a support. Said binder comprised in the lower layer and/or magnetic layer comprises a polyurethane, said polyurethane is polyurethane (1) prepared from a chain extending agent, an organic diisocyanate, and a polyester polyol which comprises a dibasic acid component and a diol component, wherein the dibasic acid component comprises an aliphatic dibasic acid component and 70 molar percent or more of the diol component is derived from a diol having an alkyl branched side chain comprising two or more carbon atoms without a ring structure, or said polyurethane is polyurethane (2) prepared from a chain extending agent which comprises an alkyl branched aliphatic diol comprising three or more of total carbon atoms in a branched side chain per molecule, an organ…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.