Back to results
US 11,017,809 B2Granted
Magnetic recording medium having a controlled dimensional variation
AssigneeSony Corporation
InventorsMinoru Yamaga, Noboru Sekiguchi
Life of this patent
Estimating the term…
Abstract
A magnetic recording medium includes a layer structure including a magnetic layer, a base layer, and a back layer in this order, in which an average thickness tT is tT≤5.5 μm, a dimensional variation Δw in a width direction to tension change in a longitudinal direction is 660 ppm/N≤Δw, and a surface roughness Rabe of the base layer on a side of the back layer is 4.2 nm≤Rabe≤8.5 nm.
Claims29
A magnetic recording medium comprising
- a layer structure including a magnetic layer, a base layer, and a back layer in this order,
- wherein an average thickness tT is tT≤5.5 μm,
- a dimensional variation Δw in a width direction to tension change in a longitudinal direction is 660 ppm/N≤Δw, and
- a surface roughness Rabe of the base layer on a side of the back layer is 4.2 nm≤Rabe≤8.5 nm, and
- wherein the dimensional change amount Δw is determined according to:
- Δ
-
- w
-
- [
- ppm
- /
- N
- ]
- =
- D
-
- (
- 0
- .
- 2
-
- N
- )
-
- [
- mm
- ]
- -
- D
-
- (
- 1
- .
- 0
-
- N
- )
-
- [
- mm
- ]
- D
-
- (
- 0.2
-
- N
- )
- [
- mm
- ]
- ×
- 1
- ,
- 000
- ,
- 000
- (
- 1
- .
- 0
-
- [
- N
- ]
- )
- -
- (
- 0
- .
- 2
-
- [
- N
- ]
- )
- where D(0.2N) and D(1.0N) represent widths of a sample of the magnetic recording medium subject to loads of 0.2N and 1.0N, respectively, in the longitudinal direction.
75 more elements
Dependencies are inferred from the claim text.