Decorative substrate, especially costume jewelry gem with color effect and method for achieving color effect in decorative transparent substrate

摘要

Decorative substrate, especially jewelery stone with a color effect, which is characterized in that it is formed by a transparent substrate which on the rear side in the following order from the back side comprises a 2-80 nm thick optically modifying layer comprises at least one element or oxide of an element from the group consisting of Ge, Si and oxides of Ti, Zr, Nb and Al, which are optionally doped with other elements, the reflective layer comprises at least one metal or alloy from the group consisting of Au, Ag, Cu, Al, Cr, Ti, aluminum bronzes and alloys of Au, Ag and Cu and having a thickness ensuring maximum possible reflection of the incident visible light in dependence on the spectral reflectivity of the material from which the reflective layer is made of, back to the transparent substrate 10 to 100 nm thick intermediate layer comprises at least one metal from the group consisting of Ti , Cr and Cu, and a layer of protective varnish. Among the optically modifying layer and the reflection layer is optionally contained 2 to 15 nm thick adhesion layer, comprising at least one metal oxide from the group consisting of metals of Al, Ti, Zr and Sn. Method of achieving a color effect for a decorative transparent substrate comprises applying said layers to the back side of the transparent substrate by sputtering in a vacuum and optionally heat treatment of the transparent substrate at a temperature higher than 150 degC, but lower than the temperature at which disrupts any of layers or undesirable interaction between the layers, for 0.5 to 8 hours.