Patent ID: 6221468
Filing Date: 2001-04-24
Classification: G11B,Y10S,Y10T

Abstract:
A magnetic recording medium comprising a nonmagnetic substrate and at least one magnetic layer provided on said nonmagnetic substrate, in which magnetic layer a ferromagnetic powder and a binder are dispersed together, wherein:said magnetic layer comprises as said binder a polyurethane obtained from a polyester polyol, a chain extender, and an organic diisocyanate, andsaid ferromagnetic powder is a ferromagnetic powder comprising cobalt-containing iron as a main component and said ferromagnetic powder has an yttrium-to-iron atomic ratio of Y/Fe=0.5 to 20 at %,said polyurethane being a polyurethane comprising a polyester polyol containing an aliphatic dibasic acid as a dibasic acid therein, and a diol component, wherein at least 70 mol % of said diol component contains an alkyl branched side chain having at least 2 carbon atoms.