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US 11,450,345 B2Granted
Magnetic recording medium, magnetic recording/reproducing device, and magnetic recording medium cartridge
AssigneeSony Corporation
InventorsMinoru Yamaga, Takanobu Iwama, Jun Takahashi
Life of this patent
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Abstract
A magnetic recording medium that can exhibit good traveling performance during use is provided. This magnetic recording medium is a tape-shaped magnetic recording medium, and includes a substrate including a polyester as a main component, a base layer disposed on the substrate, and a magnetic layer disposed on the base layer. The kurtosis of the surface of the magnetic layer is 3.0 or more. The base layer and the magnetic layer each include a lubricant including a fatty acid and a fatty acid ester. In the lubricant, a ratio of the content of the fatty acid to the content of the fatty acid ester is less than 0.6.
Claims19
A tape-shaped magnetic recording medium comprising:
- a substrate;
- a base layer disposed on the substrate;
- and
- a magnetic layer disposed on the base layer, wherein
- the substrate includes a polyester as a main component,
- a surface of the magnetic layer opposite to the base layer has a kurtosis of 3.0 or more,
- the base layer and the magnetic layer each include a lubricant including a fatty acid and a fatty acid ester,
- in the lubricant, a ratio of a content of the fatty acid to a content of the fatty acid ester (fatty acid/fatty acid ester) is less than 0.6
- a surface of the magnetic layer has arithmetic average roughness Ra of 2.5 nm or less,
- the entire magnetic recording medium has a BET specific surface area of 3.5 m2/g or more in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried,
- a squareness ratio in a perpendicular direction is 65% or more,
- the magnetic layer has an average thickness of 90 nm or less, and
- the magnetic recording medium has an average thickness of 5.6 μm or less.
10 more elements
A magnetic recording/reproducing device comprising:
- a feeding unit that can sequentially feed out a tape-shaped magnetic recording medium;
- a winding unit that can wind up the magnetic recording medium fed out from the feeding unit;
- and
- a magnetic head that can write information on the magnetic recording medium and can read out information from the magnetic recording medium while being in contact with the magnetic recording medium traveling from the feeding unit toward the winding unit, wherein
- the magnetic recording medium includes:
- a substrate;
- a base layer disposed on the substrate;
- and
- a magnetic layer disposed on the base layer,
- the substrate includes a polyester as a main component,
- a surface of the magnetic layer opposite to the base layer has a kurtosis of 3.0 or more,
- the base layer and the magnetic layer each include a lubricant including a fatty acid and a fatty acid ester,
- in the lubricant, a ratio of a content of the fatty acid to a content of the fatty acid ester (fatty acid/fatty acid ester) is less than 0.6
- a surface of the magnetic layer has arithmetic average roughness Ra of 2.5 nm or less,
- the entire magnetic recording medium has a BET specific surface area of 3.5 m2/g or more in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried,
- a squareness ratio in a perpendicular direction is 65% or more,
- the magnetic layer has an average thickness of 90 nm or less, and
- the magnetic recording medium has an average thickness of 5.6 μm or less.
15 more elements
A magnetic recording medium cartridge comprising:
- a tape-shaped magnetic recording medium;
- and
- a casing that houses the magnetic recording medium, wherein
- the magnetic recording medium includes:
- a substrate;
- a base layer disposed on the substrate;
- and
- a magnetic layer disposed on the base layer,
- the substrate includes a polyester as a main component,
- a surface of the magnetic layer opposite to the base layer has a kurtosis of 3.0 or more,
- the base layer and the magnetic layer each include a lubricant including a fatty acid and a fatty acid ester,
- in the lubricant, a ratio of a content of the fatty acid to a content of the fatty acid ester (fatty acid/fatty acid ester) is less than 0.6
- a surface of the magnetic layer has arithmetic average roughness Ra of 2.5 nm or less,
- the entire magnetic recording medium has a BET specific surface area of 3.5 m2/g or more in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried,
- a squareness ratio in a perpendicular direction is 65% or more,
- the magnetic layer has an average thickness of 90 nm or less, and
- the magnetic recording medium has an average thickness of 5.6 μm or less.
14 more elements
Dependencies are inferred from the claim text.