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US 10,589,497 B2Granted
Biaxially oriented polyester film
AssigneeToray Industries, Inc.
InventorsYukari Nakamori, Takuji Higashioji, Masato Horie
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AssigneeToray Industries, Inc.
InventorsYukari Nakamori, Takuji Higashioji, Masato Horie
Estimating the term…
A biaxially orientated polyester film has a PL/VL ratio of 0.3 to 1.2, PL and VL representing the average diameter of the convex portions and the average diameter of the concave portions, respectively, that are defined on the basis of a slice level with a height of 0 nm (reference plane) in a roughness curve determined for at least one surface using a three dimensional surface roughness meter, and the convex portions accounting for an area ratio of 30% to 51% of the reference plane. The biaxially oriented polyester film is excellent in travelling property, slitting property, and dimensional stability, and serves, when used for magnetic recording medium production, to provide a high density magnetic recording medium having a smooth magnetic layer, suffering little dimensional change due to variations in environmental parameters such as temperature and humidity or due to storage, and having good electromagnetic conversion characteristics with little dropout.
A biaxially orientated polyester film having a PL/VL ratio of 0.3 to 1.2, PL and VL representing an average diameter of convex portions and an average diameter of concave portions, respectively, defined on the basis of a slice level with a height of 0 nm (reference plane) in a roughness curve determined for at least one surface using a three dimensional surface roughness meter, and the convex portions accounting for an area ratio of 30% to 51% of the reference plane.
Dependencies are inferred from the claim text.