Patent ID: 9255193
Filing Date: 2016-02-09
CPC Classification: B05D,C08J,D21H,Y10T

Claim Text:
1. A process for forming a film, having water, grease, gas and water vapor barrier properties, at the surface of a substrate which comprises the following successive steps: coating the substrate with PVA to form a PVA film, in which the PVA has a molecular weight greater than 13,000 and a degree of hydrolysis greater than 81%; drying the PVA film; printing an activated fatty acid having at least 12 carbon atoms in absence of solvent on a surface of the PVA film; and after that placing the PVA film with the activated fatty acid deposited thereon under nitrogen flushing with a light vacuum in a ventilated chamber at a temperature in the ventilated chamber above the melting point of the activated fatty acid and below the melting point of the PVA, so that the activated fatty acid is grafted with the PVA film at the surface of the PVA film by esterification in heterogeneous phase.