Magnetic tape
The magnetic tape has a magnetic layer containing ferromagnetic powder, abrasive, and binder on a nonmagnetic support, wherein the centerline average surface roughness Ra measured on the surface of the magnetic layer is less than or equal to 1.8 nm, the contact angle for 1-bromonaphthalene that is measured on the surface of the magnetic layer falls within a range of 45.0° to 60.0°, and the coefficient of friction that is measured on the base portion of the surface of the magnetic layer is less than or equal to 0.35.
1. A magnetic tape,
which comprises a magnetic layer comprising ferromagnetic powder, abrasive, and binder on a nonmagnetic support, wherein:
a centerline average surface roughness Ra measured on a surface of the magnetic layer is less than or equal to 1.8 nm;
a contact angle for 1-bromonaphthalene that is measured on the surface of the magnetic layer falls within a range of 45.0° to 60.0°; and
a coefficient of friction that is measured on a base portion of the surface of the magnetic layer is less than or equal to 0.35.
2. The magnetic tape according to claim 1 ,
wherein the centerline average surface roughness Ra falls within a range of 1.2 nm to 1.8 nm.
3. The magnetic tape according to claim 1 ,
wherein the centerline average surface roughness Ra falls within a range of 1.2 nm to 1.6 nm.
4. The magnetic tape according to claim 1 ,
wherein the coefficient of friction that is measured on the base portion of the surface of the magnetic layer falls within a range of 0.15 to 0.35.
5. The magnetic tape according to claim 1 ,
wherein the contact angle for 1-bromonaphthalene that is measured on the surface of the magnetic layer falls within a range of 45.1° to 60.0°.
6. The magnetic tape according to claim 1 ,
wherein the coefficient of friction that is measured on the base portion of the surface of the magnetic layer falls within a range of 0.20 to 0.35.
7. The magnetic tape according to claim 1 ,
wherein the contact angle for 1-bromonaphthalene that is measured on the surface of the magnetic layer falls within a range of 45.10° to 60.0°; and
the coefficient of friction that is measured on the base portion of the surface of the magnetic layer falls within a range of 0.20 to 0.35.
8. The magnetic tape according to claim 1 ,
wherein a contact angle for water measured on the surface of the magnetic layer falls within a range of 90.0° to 101.2°.
9. The magnetic tape according to claim 1 ,
wherein a contact angle for water measured on the surface of the magnetic layer falls within a range of 96.8° to 101.2°.
10. The magnetic tape according to claim 1 ,
wherein the contact angle for 1-bromonaphthalene that is measured on the surface of the magnetic layer falls within a range of 45.1° to 60.0°;
the coefficient of friction that is measured on the base portion of the surface of the magnetic layer falls within a range of 0.20 to 0.35; and
a contact angle for water measured on the surface of the magnetic layer falls within a range of 96.8° to 101.2°.
11. The magnetic tape according to claim 1 ,
wherein the magnetic layer comprises one or more lubricants selected from the group consisting of a fatty acid, a fatty acid ester, and a fatty acid amide.
12. The magnetic tape according to claim 1 ,
wherein the magnetic layer comprises a nitrogen-containing polymer.
13. The magnetic tape according to claim 12 ,
wherein the nitrogen-containing polymer is a polyalkyleneimine polymer.
14. The magnetic tape according to claim 13 ,
wherein the polyalkyleneimine polymer is a polymer comprising a polyalkyleneimine chain and a polyester chain.
15. The magnetic tape according to claim 1 ,
which comprises a nonmagnetic layer comprising nonmagnetic powder and binder between the nonmagnetic support and the magnetic layer.
16. The magnetic tape according to claim 1 ,
which comprises a backcoat layer comprising nonmagnetic powder and binder on an opposite side of the nonmagnetic support from that on which the magnetic layer is present.