Biaxially oriented film having specified micro protrusions
AssigneeToray Industries, Inc.
InventorsAkira Kubota, Shoji Nakajima, Yukari Nakamori, Tetsuya Tsunekawa
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Abstract
An object of the present invention is to provide a high-quality biaxially oriented film exhibiting an excellent electromagnetic conversion property, traveling durability, magnetic head traveling performance, etc. as a magnetic recording medium. The object of the present invention is achieved by a biaxially oriented film including a polymer alloy composed of polyester (polymer 1) and a thermoplastic resin (polymer 2) other than the polyester as essential components, wherein micro protrusions having a height of 2 to 50 nm are formed at a density of 1,000,000 to 90,000,000/mm2 on at least one surface.
Claims25
A biaxially oriented film comprising;
- at least two layers including a film layer A of a polymer alloy composed of at least one of polyethylene terephthalate or poly(ethylene-2,6-naphthalenedicarboxylate) (polymer 1) and a polyetherimide (polymer 2) as essential components, and a base layer B;
- said film layer A being laminated as an outermost layer to the base layer B;
- wherein a content WA (% by weight) of the Polymer 2 of the film layer A and a content WB (% by weight) of the polymer 2 of the base layer B satisfy the following relations:
- 0≦WB≦40
- 5≦WA≦50
- 10≦WA−WB≦40;
- and
- wherein micro protrusions having a height of 2 to 50 nm are formed at a density of 1,000,000 to 90,000,000/mm2 on an outer surface of the film layer A.
Dependencies are inferred from the claim text.