| abstract |
Adhesive compositions comprising (a) adhesive polymers or copolymers prepared from monomers selected from the group consisting of styrene, butadiene, acrylonitrile, ethylene, vinyl acetate, acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters and their combinations; and (b) between 1 and 55% on the dry weight basis of a polymeric additive comprising a low molecular weight polymer having a number average molecular weight of 20,000 or less and comprising polymerized units of at least one ethylenically monomer unsaturated and 5 percent by weight or less of a monomer containing polymerized acid. Preferably, the polymeric additive is polymerized in the presence of a metal chelate chain transfer agent. In certain embodiments, the polymeric additive has a midpoint Tg of at least 0 degree Co more. Other embodiments of the present invention include methods for forming the polymer additive in situ in the adhesive composition. |