Magnetic recording medium
AssigneeSony Corporation
InventorsMinoru Yamaga, Takanobu Iwama, Jun Takahashi
Life of this patent
Estimating the term…
Abstract
A tape-shaped magnetic recording medium is provided with a base, an underlayer provided on the base, and a magnetic layer provided on the underlayer including magnetic powder including hexagonal ferrite. The underlayer and the magnetic layer include lubricant. The magnetic layer includes a surface provided with a large number of holes, and arithmetic average roughness Ra of the surface is 2.5 nm or smaller. A BET specific surface area of a whole of the magnetic recording medium in a state in which the lubricant is removed is 3.5 m2/mg or larger. A square ratio in a vertical direction is 65% or larger, an average thickness of the magnetic layer is 90 nm or smaller, and an average thickness of the magnetic recording medium is 5.6 μm or smaller.
Claims18
A tape-shaped magnetic recording medium comprising:
- a base;
- an underlayer provided on the base;
- and
- a magnetic layer provided on the underlayer and including magnetic powder including hexagonal ferrite,
- wherein the underlayer and the magnetic layer include a lubricant,
- the magnetic layer includes a surface provided with a large number of holes,
- arithmetic average roughness Ra of the surface is 2.5 nm or smaller,
- a BET specific surface area of a whole of the tape-shaped magnetic recording medium in a state in which the lubricant is removed is 3.5 m2/mg or larger and 5.5 m2/mg or less,
- a square ratio in a vertical direction is 65% or larger,
- an average thickness of the magnetic layer is 90 nm or smaller, and
- an average thickness of the tape-shaped magnetic recording medium is 5.6 μm or smaller.
Dependencies are inferred from the claim text.