Patent ID: 8617728
Filing Date: 2013-12-31
Classification: G11B

Abstract:
1. A magnetic tape 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 component comprises a radiation-curable polyurethane resin that has been radiation-cured and obtained from starting materials containing a sulfonic acid group containing- or sulfonate group-containing polyol compound denoted by formula (2a): wherein, in formula (2a), X denotes a divalent linking group; each of R the nonmagnetic radiation-cured layer has a thickness ranging from 0.5 to 1.3 μm, a relation between the nonmagnetic powder and the binder component contained in the radiation-curable composition satisfies equation (I) below: and the binder component further comprises a radiation-curable vinyl chloride copolymer containing a structural unit denoted by formula (1): wherein, in formula (1), R wherein, in formula (4), R