Patent ID: 7452573

Claim:
The method of making a substrate having an oxygen barrier property comprising applying a solution or dispersion of an oxygen barrier material to a substrate, said barrier material being at least one of water soluble oxygen barrier material, water dispersible oxygen barrier material and mixtures thereof, said barrier material being blended with a nanoparticle calcium carbonate having a size in the range of 10 to 250 nanometers, the weight ratio of nanoparticle calcium carbonate to said water soluble or water dispersible oxygen barrier material being in the range of 1:100 to 1.5:1 and applying heat and pressure to said barrier material, the substrate and the calcium carbonate, and applying a layer of material over said barrier material on the side opposite said substrate, to provide a material having an oxygen transfer rate of 30 or less cc/m 2 /day of oxygen at standard temperature and pressure and 50% relative humidity.