Magnetic tape, magnetic tape cartridge, and magnetic tape device
The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder, in which an edge portion Ra which is an arithmetic average roughness Ra measured at an edge portion of a surface of the magnetic layer is 1.50 nm or less, a central portion Ra which is an arithmetic average roughness Ra measured at a central portion of the surface of the magnetic layer is 0.30 nm to 1.30 nm, and a Ra ratio (central portion Ra/edge portion Ra) is 0.75 to 0.95.
1. A magnetic tape comprising:
a non-magnetic support; and
a magnetic layer containing a ferromagnetic powder,
wherein an edge portion Ra which is an arithmetic average roughness Ra measured at an edge portion of a surface of the magnetic layer is 1.50 nm or less,
a central portion Ra which is an arithmetic average roughness Ra measured at a central portion of the surface of the magnetic layer is 0.30 nm to 1.30 nm, and
a Ra ratio (central portion Ra/edge portion Ra) is 0.75 to 0.95.
2. The magnetic tape according to claim 1 , further comprising:
a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer.
3. The magnetic tape according to claim 2 ,
wherein the non-magnetic powder contains a Fe-based inorganic oxide powder having an average particle volume of 2.0×10 −6 μm 3 or less.
4. The magnetic tape according to claim 2 ,
wherein the non-magnetic powder contains carbon black having a pH of 5.0 or less.
5. The magnetic tape according to claim 2 ,
wherein the non-magnetic powder contains a Fe-based inorganic oxide powder having an average particle volume of 2.0×10 −6 μm 3 or less and carbon black having a pH of 5.0 or less.
6. The magnetic tape according to claim 2 ,
wherein the non-magnetic powder contains a Fe-based inorganic oxide powder having an average particle volume of 2.0×10 −6 μm 3 or less and carbon black having a pH of 5.0 or less, and
a standard deviation of curvature of the magnetic tape in a longitudinal direction is 5 mm/m or less.
7. The magnetic tape according to claim 2 ,
wherein the non-magnetic powder contains a Fe-based inorganic oxide powder having an average particle volume of 2.0×10 −6 μm 3 or less and carbon black having a pH of 5.0 or less,
a standard deviation of curvature of the magnetic tape in a longitudinal direction is 5 mm/m or less,
a tape thickness is 5.2 μm or less, and
a vertical squareness ratio of the magnetic tape is 0.60 or more.
8. The magnetic tape according to claim 1 ,
wherein a standard deviation of curvature of the magnetic tape in a longitudinal direction is 5 mm/m or less.
9. The magnetic tape according to claim 1 , further comprising:
a back coating layer containing a non-magnetic powder on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer.
10. The magnetic tape according to claim 1 ,
wherein a tape thickness is 5.2 μm or less.
11. The magnetic tape according to claim 1 ,
wherein a vertical squareness ratio of the magnetic tape is 0.60 or more.
12. A magnetic tape cartridge comprising:
the magnetic tape according to claim 1 .
13. A magnetic tape device comprising:
the magnetic tape according to claim 1 .
14. The magnetic tape device according to claim 13 , further comprising:
a magnetic head,
wherein the magnetic head includes a module including an element array having a plurality of magnetic head elements between a pair of servo signal reading elements, and
the magnetic tape device changes an angle θ formed by an axis of the element array with respect to a width direction of the magnetic tape during running of the magnetic tape in the magnetic tape device.