SILVER LAYER FORMED BY ELECTROSILVERING SUBSTRATE MATERIAL

摘要

A silver layer formed by electro-plating silver on a substrate material is provided to achieve high reflectivity of 90 to 99% in a visible ray region by setting a crystal grain size in a range of 0.5 mum to 30mum at the outermost surface of the silver layer. A silver layer formed by electro-plating silver on a substrate material(1) comprises an outermost surface having a crystal grain size of 0.5 mum to 30mum. A silver plated layer(6) has a film thickness of 1mum or above, and includes copper. The silver plated layer has a film thickness of 4mum or above, and includes nickel. The substrate material has a surface roughness of 0.5 mum or above. The nickel dose not contains sulfur. The silver plated layer is heated in a temperature of 200°C or above for 30 minutes or above after the electro-slivering process.