THERMALLY CURABLE PRECURSOR OF A TOUGHENED THERMO-EXPANDED FILM AND A FILM MADE THEREOF

摘要

Precursor of a toughened foamed film comprising a. 30 - 60 wt. % of at least one epoxy compound with an average epoxy equivalent weight of at least 350 g, b. 10-25 wt. % of at least one epoxy compound with an average epoxy equivalent weight of less than 200 g, c. 2 - 40 wt. % of at least one epoxy curing agent, d. 10 - 30 wt. % of at least one toughening agent, and e. at least one blowing agent wherein the mass ratio of the epoxy components a and b and the amount of the toughening component d is selected to provide a floating roller peel strength of the cured film of at least 150 N/25 mm at 23 °C and/or a shear impact strength of at least 12 kN/m² at 23 °C.