STRUCTURAL ADHESIVE AND BONDING APPLICATION THEREOF

摘要

A structural adhesive composition that is suitable for high-strength bonding of metals and aerospace structural materials. In one embodiment, the structural adhesive composition based on a two-part system, which is curable at or below 200°F (93 °C). The two-part system is composed of a resinous part (A) and a catalyst part (B), which may be stored separately at room temperature until they are ready to be used. The resinous part (A) includes at least two different multifunctional epoxy resins with different functionality selected from difunctional, trifunctional, and tetrafunctional epoxy resins, certain toughening components, and inorganic filler particles as a rheology/thixotrophy modifying component. The toughening components include core-shell rubber particles with different particle sizes and at least one of an elastomeric polymer and a polyethersulfone polymer. The catalyst part (B) includes an aliphatic or cyclic amine compound as a curing agent and inorganic filler as a rheology/thixotropy modifying component. The weight ratio of part (A) to part (B) is within the range of 3:2 to 10:2. In another embodiment, the structural adhesive composition is based on a one-part system which includes the components of the resinous part (A) in the two-part system mixed with a latent amine curing agent. The one-part system may further include an imidazole and/or an aliphatic amine. The one-part system is curable within the temperature range of 140-300°F (60-150°C). The paste adhesive disclosed herein has film-like properties and is particularly useful in rapid-assembly aerospace structure bonding applications.