| abstract |
An adhesive composition which, in the preferred aspects of the invention, is a partially cured reaction product of the composition in the form of a dried, preformed film that is heat-activatable, is provided comprising in admixture a poly-functional active hydrogen containing component consisting of, in combination, a hydroxyl terminated polyurethane polyester having a hydroxyl number no greater than about 15 and a member containing at least difunctional active hydrogen having an active hydrogen equivalent weight of at least about 27 and less than about 500, a component having available free isocyanate groups, and a fourth component such as a chlorinated aliphatic hydrocarbon, a chlorinated aromatic hydrocarbon, or an alkylated polystyrene. The partially cured, preformed adhesive film of this invention permits joint formation under pressure at relatively low temperatures and over a relatively wide temperature range, thereby making it possible to join together various materials which would otherwise present a problem in joining because of their lack of heat resistance. Joints formed have unusually high resistance to flexural fatigue. |