Polyester film for magnetic recording media
AssigneeTeijin Limited
InventorsHideo Katoh, Kinji Hasegawa
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Abstract
A biaxially oriented polyester film for use in thin metallic film-type magnetic recording media, said polyester film having a first surface to which a thin metallic film as a magnetic recording layer is to be applied and a second surface coated with an easily slippable layer composed of an organic polymeric binder and inert fine solid particles dispersed therein, the first surface having (a) large protrusions with a diameter of 0.2 to 2 micrometers and a height of 20 to 200 angstrom distributed at a density of at least 10.sup.3 but less than 10.sup.6 per mm.sup.2, and (b) small protrusions with a diameter of 0.01 to 0.1 micrometer and a height of 10 to 100 angstrom distributed at a density of from 10.sup.6 up to 10.sup.9.
Claims9
A biaxially oriented polyester film for use in thin metallic film-type magnetic recording media, said polyester film having a first surface to which a thin metallic film as a magnetic recording layer is to be applied and a second surface coated with an easily slippable layer composed of an organic polymeric binder and inert fine solid particles dispersed therein, the first surface having (a) large protrusions with a diameter of 0.2 to 2 micrometers and a height of 20 to 200 angstrom distributed at a density of at least 10.sup.3 but less than 10.sup.6 per mm.sup.2, and (b) small protrusions with a diameter of 0.01 to 0.1 micrometer and a height of 10 to 100 angstrom distributed at a density of from 10.sup.6 up to 10.sup.9 per mm.sup.2.
Dependencies are inferred from the claim text.