STRUCTURAL ADHESIVE AND BONDING APPLICATION THEREOF

摘要

A curable adhesive film formed from an adhesive composition comprising: at least two different multifunctional epoxy resins selected from difunctional, trifunctional, and tetrafunctional epoxy resins; smaller core-shell rubber particles having particle sizes less than 100 nm and a larger core-shell rubber particles having particle sizes greater than 100 nm, the weight ratio of the smaller particles to the larger particles being in the range of 3:1 to 5:1; at least one of an elastomeric polymer with an epoxy functional group and a polyethersulfone polymer having an average molecular weight in the range of 8,000-14,000; inorganic filler particles; and a latent amine-based curing agent selected from dicyandiamide (DICY), guanamine, guanidine, aminoguanidine, and derivatives thereof, and an imidazole-based catalyst encapsulated within a crystalline polymer network, wherein, upon curing, the adhesive film has the following properties: a glass transition temperature (Tg) of greater than 100° C. (212° F.) upon curing in the temperature range of 65° C.-93° C. (150° F.-200° F.), a lap shear strength of 28-40 MPa at 20-25° C. and 25-28 MPa at 82° C., 17-21 MPa at 121° C. according to ASTM D3165, a peel strength of 150-250 Nm/m (30-50 lbs/in) at 20° C.-25° C. according to ASTM D3167.