| 摘要 |
<p>A two pack composition comprises a first pack comprising a solution or dispersion of polyvinyl alcohol (PVA) and/or ethylene-vinyl alcohol copolymer (EVOH) and a second pack comprising an aqueous dispersion of a clay. The clay may be kaolinite, montmorillonite, atapulgite, illite, bentonite, halloysite, kaolin, mica, diatomaceous earth. Fuller's earth, aluminium silicate, magnesium aluminium silicate, sodium silicate, or magnesium silicate. Preferably, the clay is intercalated or exfoliated during dispersion and has an aspect ratio of 20-10000. A process for preparing a gas barrier material is also disclosed by mixing the two packs. The resulting mixture is coated onto a first polymer film and an adhesive is applied to the coated film and/or a second polymer film. The first and second films are then adhered together, the bond strength between the films being at least 1.0N/15mm. The gas barrier material is useful for packaging foodstuffs and pharmaceuticals.</p> |
