Multi-layer composite film having a security feature

摘要

Described is a multi-layer composite film comprising, (a) a biaxially oriented polypropylene film as a base film; (b) at least one polyolefin film superposed over said biaxially oriented polypropylene film; and (c) a colorant deposited on the polyolefin film. The colorant is interposed between the biaxially oriented polypropylene film and at least one of the superposed polyolefin films, and the thickness of the multi-layer composite film ranges between 8 mum and 26 mum. Also described are a method of producing the multi-layer composite film, and a method of using the multi-layer composite film as a packaging material.