Patent ID: 7520972

Claim:
A process for making a mold piece having a main curved surface bearing a microstructure comprising: (a) providing a master piece having a flat main surface bearing a microstructure; (b) transferring said microstructure from the master piece main surface to a main surface of a flat cured elastomeric film; (c) recovering the flat cured elastomeric film having a main surface bearing a replica of said microstructure; (d) providing a master article having a main curved surface to be replicated; (e) applying a curable coating composition either: on the main curved surface of the master article, or on the main surface bearing the replica of said microstructure of the flat cured elastomeric film, or on both main surfaces; (f) placing the main surface bearing the replica of said microstructure of the flat cured elastomeric film and the main curved surface of the master article in front of each other; (g) pressing said cured elastomeric film and said master article against each other so as to conform the overall shape of said cured elastomeric film to the curved shape of the main surface of the master article and to spread over the curable coating composition between the curved main surface of the master article and the main surface bearing the replica of the said microstructure of the cured elastomeric film; (h) curing the coating composition; (i) removing the cured elastomeric film and recovering a hard coated article having a main curved surface coated with a hard coating having an exposed main surface bearing a transferred microstructure; (j) depositing a layer of a metal or a metallic alloy on said exposed main surface of the hard coating of the master article; and (k) recovering said metal or metallic alloy layer to obtain a mold piece having a curved main surface bearing a replica of said transferred microstructure.