POLYESTER FILM WITH CITRIC ACID-MODIFIED POLYVINYL AMINE

摘要

A composite barrier film has a base layer of polyester with a barrier layer modified polyvinyl amine (mPVA). The mPVA is polyvinyl alcohol/polyvinyl amine copolymer crosslinked with citric acid and an optional additional crosslinking agent such as epichlorohydrin. The barrier layer can be applied by deposition of a reactive aqueous solution onto the base layer, heating and drying to remove water and crosslink the reactants. Excellent barrier properties of the film are obtained by applying and crosslinking the barrier layer during the transverse stretching steps of a biaxial oriented polymer film continuous fabrication process. Superior barrier properties are achieved with transverse stretching by a factor of about 3-4.

主权项

1. A composite barrier film comprising (A) a base layer defining a base layer thickness, the base layer comprising a core layer comprising a polymer of polyester, and (B) a barrier layer coextensively adjacent in direct contact with one side of the base layer, the barrier layer defining a barrier layer thickness and comprising modified polyvinyl amine,
in which the modified polyvinyl amine is a vinylamine polymer crosslinked by citric acid, in which the composite barrier film is optically clear, and in which the composite barrier film has moisture vapor transmission rate and oxygen transmission rate at most equal to that of a composite control film consisting essentially of a substrate identical to the base layer, and a layer of polyvinyl alcohol of thickness equal to the barrier layer thickness and disposed coextensively on the substrate.