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US 5,472,778 AGranted
Magnetic recording medium
AssigneeTDK Corporation
InventorsKunihiro Ueda, Takayoshi Kobuke
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Abstract
A magnetic recording medium having a magnetic layer in the form of a ferromagnetic metal thin film includes an undercoat film disposed between the magnetic layer and the substrate and a topcoat film on the magnetic layer. Each of the undercoat and topcoat films is a plasma polymerized film containing silicon, the Si content in the film being 30 to 50 at %. Corrosion resistance and durability are significantly improved.
Claims5
A magnetic recording medium comprising an undercoat film, a ferromagnetic metal thin film, and a topcoat film on a non-magnetic resin substrate,
- wherein each of said undercoat film and said topcoat film is a plasma polymerized film containing silicon, the Si content in the films being 30 to 50 at %,
- said plasma polymerized films contain oxygen and silicon in an atomic ratio O:Si of from 1.2:1 to 1.95:1,
- said plasma polymerized films are formed by feeding an alkoxysilane compound and oxygen gas as reactants at a flow rate ratio of alkoxysilane compound to oxygen of from 0.1:1 to 0.6:1,
- said plasm polymerized films have an index of refraction of 1.44 to 1.55,
- said undercoat film is 100 to 1000 .ANG. thick, and
- said topcoat film is 10 to 100 .ANG. thick, and
- wherein said ferromagnetic metal thin film is formed by an oblique evaporation technique.
4 more elements
Dependencies are inferred from the claim text.