Optical information recording medium in which a protective layer comprises a Ni-Cr alloy layer
AssigneeNEC Corporation
InventorMasaki Itoh
Life of this patent
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Abstract
In an optical information recording medium comprising a substrate (11) of polycarbonate, a recording layer, and a reflecting layer (14) covering the reflecting layer and containing Al, an alloy layer (17) of a Ni-Cr alloy is deposited on the reflecting layer to sufficiently protect transmission of moisture into the reflecting layer. A covering layer (18) of ultraviolet curable resin may be deposited on the alloy layer. The recording layer is formed on the substrate and includes a magneto-optical layer (13) sandwiched between first and second interference layers (15, 16). For protecting transmission of moisture into the substrate, it is preferable that an additional layer (21) of SiO.sub.2 is deposited on the substrate opposite to the recording layer.
Claims9
An optical information recording medium comprising a substrate, a protective layer, a recording layer between said substrate and said protective layer, and a reflecting layer between said protective layer and said recording layer, said reflecting layer containing Al, said protective layer comprising an alloy layer of a Ni-Cr alloy on said reflecting layer, said Ni-Cr alloy containing 20% by weight of Cr.
Dependencies are inferred from the claim text.