MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain a recording medium having excellent traveling durability by superposing at least two magnetic layers and using a specific polyurethane resin for the binder of the lower layer and the specific polyurethane resin and polyisocyanate for the binder of the upper layer. CONSTITUTION:Coated films are formed on a nonmagnetic base by superposing the 1st and 2nd magnetic layers thereon. The binder of the 1st magnetic layer contains the polyurethane resin having <25,000 number average mol.wt. and the glass transition temp. thereof is specified to <0 deg.C. The binder of the 2nd magnetic layer contains the polyurethane resin contg. org. groups having active hydrogen at a ratio of >=3 pieces per 1 molecule and having >=25,000 number average mol.wt. and the polyisocyanate. The org. groups having the active hydrogen are one kind of OH and NH3NHR (R is an alkyl group) and the binder contains a vinyl chloride copolymer in addition to the polyurethane resin. The recording medium having a good still characteristic and the excellent traveling durability is obtd. according to this constitution.