Magnetic recording medium and method of manufacturing the same

摘要

An aspect of the present invention relates to a magnetic recording medium comprising a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein the binder of the magnetic layer is a mixture of a vinyl chloride copolymer, polyurethane resin, and polyisocyanate, the polyurethane resin having a glass transition temperature ranging from 90 to 130° C. and a storage elastic modulus at 80° C. ranging from 2.5 to 5.0 GPa, the nonmagnetic layer is a radiation-cured layer formed by curing with radiation a radiation-curable composition comprising a nonmagnetic powder and a binder component, the binder component comprising a radiation-curable vinyl chloride copolymer and a radiation-curable polyurethane resin, and the radiation-curable vinyl chloride copolymer and radiation-curable polyurethane resin both have glass transition temperatures ranging from 30 to 100° C.

主权项

1. A magnetic recording medium comprising a nonmagnetic radiation-cured layer containing a nonmagnetic powder and a binder component and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein
the binder of the magnetic layer is a mixture of a vinyl chloride copolymer, polyurethane resin, and polyisocyanate, the polyurethane resin having a glass transition temperature ranging from 90 to 130° C. and a storage elastic modulus at 80° C. ranging from 2.5 to 5.0 GPa, the nonmagnetic radiation-cured layer is a radiation-cured layer formed by curing with radiation a radiation-curable composition comprising the nonmagnetic powder and the binder component, the binder component comprising a radiation-curable vinyl chloride copolymer and a radiation-curable polyurethane resin, the radiation-curable vinyl chloride copolymer and radiation-curable polyurethane resin both have glass transition temperatures ranging from 30 to 100° C., and the radiation-curable vinyl chloride copolymer comprises a structural unit denoted by formula (1): wherein, in formula (1), R1 denotes a hydrogen atom or a methyl group, and L1 denotes a divalent linking group denoted by formula (2), formula (3), or formula (4): wherein, in formula (4), R41 denotes a hydrogen atom or a methyl group.