Patent ID: 8617728

Claim:
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 101 and R 102 independently denotes an alkyl group containing at least one hydroxyl group and equal to or more than two carbon atoms or an aralkyl group containing at least one hydroxyl group and equal to or more than eight carbon atoms; and M 1 denotes a hydrogen atom or a cation; the nonmagnetic radiation-cured layer has a thickness ranging from 0.5 to 1.3 Î¼m, a relation between the nonmagnetic powder and the binder component contained in the radiation-curable composition satisfies equation (I) below: 480â‰¦(BET specific surface area of the nonmagnetic powder (m 2 /g)Ã—weight of the nonmagnetic powder (g))/weight of the binder component (g)â‰¦650â€ƒâ€ƒ(I); 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 1 denotes a hydrogen atom or a methyl group, and L 1 denotes a divalent linking group denoted by formula (2), formula (3), or formula (4); wherein, in formula (4), R 41 denotes a hydrogen atom or a methyl group.