Adhesive for difficult to bond surfaces

摘要

Improved aqueous emulsion vinyl acetate-ethylene (VAE) polymer adhesives for use in packaging applications and on difficult to bond surfaces such as polyethylene, poly(ethylene terephthalate), and oriented polypropylene. The VAE polymers contain about 55-80 wt % vinyl acetate, 15-45 wt % ethylene, and 0-30 wt % of one or more additional ethylenically unsaturated copolymerizable monomer, based on the total weight of monomers. Cast films of the VAE emulsion polymers of this invention should have a tensile storage modulus (test frequency of 6.28 rad/sec) within the area encompassed by the following data points: 1x105 and 2x107 dynes/cm2 at 23 DEG C., and 1x103 and 2x106 dynes/cm2 at 70 DEG C.; preferably within the area encompassed by the following data points: 1x106 and 1.5x107 dynes/cm2 at 23 DEG C., and 3x104 and 9x105 dynes/cm2 at 70 DEG C.