AQUEOUS DISPERSIONS COMPRISING POLYURETHANE AND ETHYLNENIC COPOLYMERS FOR HEAT SEALABLE COATINGS

摘要

A film forming aqueous dispersion having utility as heat seal coatings for blister packaging applications comprises a blend of 10-90% by weight of one or more polyurethane dispersions; 90-10% by weight one or more compatible ethylenic copolymer dispersions/emulsions; an anti-blocking additive at 0.1-12 weight % of the total solids; and optional additives including wetting, defoaming, thickener, antifungal additives. The heat seal coating compositions provide enhanced and balanced properties such as a reduction of organic solvents, a tack free coating surface off the press, good press runnability, easy clean-up, antiblocking from ambient temperature to 50 °C, heat-activation with no pot life at elevated temperatures, and, heat sealability to various plastic substrates including Virgin Poly(ethylene terephthalate) (PET), recycle PET (RPET), Amorphous PET (APET), PET-Glycol modified (PETG), PETG/APET/PETG (GAG) and Polyvinyl chloride (PVC).