Hyperbranched polyesters can be widely used in coatings, either as direct additives, curing agent or as a coating material, have shown superior property compared with conventional additives . Hyperbranched polyester with double bonds nidified in the UV-curable coatings has outstanding performance. Such as for flexible material, showing excellent resistance to oxygen permeability, the PET and PP were increased resistance to oxygen permeability of 2.3 times and 15 times, in addition, it conglutinates well with the PET and PP packaging substrate. It has promising applications prospects.Weihai CY Dendrimer Technology Co. Ltd.-Professional Manufacturer for low cost dendritic polymers, forwards from Barrier coating for flexible packaging based on hyperbranched resins Lange, E Stenroos, M Johansson Department of polymer technology, Royal Institute of Technology,S-100 44 Stockholm Sweden Polymer,2001,42,7403-7410