Magnetic recording medium comprising magnetic particles and a specified polyurethane resin

摘要

A magnetic recording medium comprise a non-magnetic support and a magnetic layer formed thereon which is made of a composition comprising ferromagnetic particles and a resinous binder. The resinous binder comprises a polyurethane resin containing at least a high molecular polyol (A) and a diisocyanate (B) as its constituents. The high molecular polyol (A) comprises a polyol (a1) having a glass-transition temperature of 20 DEG C. or more and having a number average molecular weight in the range of 500 to 10,000, and the polyurethane resin has at least one hydroxyl group at its molecular terminals and the urethane bond concentration of the polyurethane resin is in the range of 500 to 1,500 equivalents/106 g.