CITRIC ACID-MODIFIED POLYVINYL AMINE FILM

摘要

A composite barrier film has a base layer of polyester or polyolefin with a barrier layer of 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 depositing 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 for continuously fabricating a biaxial oriented polymer film. Superior barrier properties are achieved with transverse stretching by a factor in the range of about 3-10 and depending upon whether the base layer is polyester or polyolefin.