Magnetic recording medium
AssigneeSony Corporation
InventorsMinoru Yamaga, Noboru Sekiguchi, Tooru Sato, Takashi Aizawa
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Abstract
A magnetic recording medium is provided and includes a magnetic layer, a non-magnetic layer, a base layer and a back layer, wherein an average thickness tT of the magnetic recording medium is tT≤5.3 μm, a dimensional change amount Δw in a width direction with respect to a change in tension in a longitudinal direction is 700 ppm/N≤Δw, a thickness of the non-magnetic layer is 2.0 μm or less, a squareness ratio measured in a vertical direction of the magnetic recording medium is 65% or more, and the magnetic layer includes a magnetic powder.
Claims38
A magnetic recording medium comprising:
- a magnetic layer,
- a non-magnetic layer,
- a base layer, and
- a back layer,
- wherein
- an average thickness tT of the magnetic recording medium is tT≤5.3 μm,
- a dimensional change amount Δw in a width direction with respect to a change in tension in a longitudinal direction is 700 ppm/N≤Δw,
- a thickness of the non-magnetic layer is 2.0 μm or less,
- a squareness ratio measured in a vertical direction of the magnetic recording medium is 65% or more,
- a width deformation coefficient b during long-term storage in a case where a long-term storage width change amount Y is defined as Y=blog(t) is −0.06≤b≤0.06, and
- the magnetic layer includes a magnetic powder,
- wherein the width coefficient b is evaluated at 32° C. and relative humidity 55%.
A magnetic recording cartridge comprising:
- a cartridge case;
- a cartridge reel which is accommodated in the cartridge case;
- and
- a magnetic recording medium which is wound around the cartridge reel, the magnetic recording medium including
- a magnetic layer,
- a non-magnetic layer,
- a base layer, and
- a back layer;
- wherein
- an average thickness tT of the magnetic recording medium is tT≤5.3 μm,
- a dimensional change amount Δw in a width direction with respect to a change in tension in a longitudinal direction is 700 ppm/N≤Δw,
- a thickness of the non-magnetic layer is 2.0 μm or less,
- a squareness ratio measured in a vertical direction of the magnetic recording medium is 65% or more,
- a width deformation coefficient b during long-term storage in a case where a long-term storage width change amount Y is defined as Y=blog(t) is −0.06≤b≤0.06, and
- the magnetic layer has a magnetic powder,
- wherein the width deformation coefficient b is evaluated at 32° C. and relative humidity 55%.
Dependencies are inferred from the claim text.