Magnetic recording medium

摘要

The invention relates to a binder which improves the dispersibility of ferromagnetic powders and makes it possible to achieve a magnetic recording medium excellent in operation durability and storability, and a magnetic recording medium using such a binder. The invention provides a magnetic recording medium including a non-magnetic support substrate and a magnetic layer formed on said support substrate, said magnetic layer comprising a dispersion of ferromagnetic fine powders in a binder, wherein said binder comprises a polyurethane resin that is a reaction product obtained by using a polyol and an organic diisocyanate as main starting materials, said polyurethane resin containing as components of said polyol 15 to 40% by weight of a short-chain diol component having a cyclic structure, and 10 to 50% by weight of a long-chain polyether polyol component, and further including a polar group-containing long-chain polyol component having a molecular weight of 500 to 5,000.