Silver alloy for reflective film of optical recording medium

Abstract

The present invention provides a silver alloy for use in a reflection coating for an optical recording medium, comprising silver as a main component and indium and/or tin as an additive element. It is preferable when the concentration of the additive elements falls within 0.1-25 wt %, and reflectivity can be inhibited from deteriorating especially when the concentration falls within a range of 0.1-5.0 wt %. When the thermal conductivity of the reflective layer is taken into account, the concentration of the additive elements may be further limited to 0.1-0.5 wt % to provide a reflective layer of higher thermal conductivity.

1 . A silver alloy for use in a reflection coating for an optical recording medium, comprising silver as a main component and indium and/or tin as an additive element.  
     
     
         2 . A silver alloy for use in a reflection coating for an optical recording medium according to  claim 1 , wherein said additive element has a concentration of 0.1-25 wt %.  
     
     
         3 . A silver alloy for use in a reflection coating for an optical recording medium according to  claim 1 , wherein said additive element has a concentration of 0.1-5.0 wt %.  
     
     
         4 . A silver alloy for use in a reflection coating for an optical recording medium according to  claim 1 , wherein said additive element has a concentration of 0.1-0.5 wt %.  
     
     
         5 . A silver alloy for use in a reflection coating for an optical recording medium according to  claim 1 , wherein the indium and/or tin as an additive element has been internally oxidized partially or wholly.  
     
     
         6 . A sputtering target comprising the silver alloy according to  claim 1.