Method for Manufacturing Flexible Substrates and Food Packaging Film Having Water Vapor and Oxygen Barrier Properties

Abstract

Disclosed herein is a method of forming a flexible moisture and oxygen barrier thin film substrate for a flexible display and food packaging, the thin film being able to increase the life-spans of organic devices. The method includes the steps of: a) uniformly dispersing plate-shape nanometer-size or micrometer-size particles in polymer solution; b) casting the polymer solution dispersed with the nanometer-size or micrometer-size particles using the solution casting method and then removing the solvent from the cast polymer solution to form a plastic film; c) stretching the formed plastic film between the glass transition temperature and melting point to exfoliate the plate-shape nanometer-size or micrometer-size particles and to orient the exfoliated nanometer-size or micrometer-size particles; d) coating the stretched plastic film with an organic film to smooth the surface of the flexible substrate; and e) heat-treating the flexible substrate to cure the organic film. The flexible substrate formed using this method serves to protect an organic device mounted on the substrate or to prevent or retard the decay and oxidation of foods by preventing the permeation of moisture (or water vapor) and oxygen.