Patent ID: 8758549

Claim:
A one-component heat-curable composition comprising: a mixture of epoxy resins and at least one latent hardener having an activation temperature above 80° C., such that the one-component heat-curable composition only undergoes curing when the latent hardener has been activated; wherein the mixture of epoxy resins comprises: a) 10 to 60 wt % of an epoxy group-containing reaction product of epichlorohydrin with polypropylene glycol that has an epoxy equivalent weight of at least 250 g/eq; b) 15 to 85 wt % of an epoxy group-containing reaction product of epichlorohydrin with a novolac resin that has an epoxy equivalent weight of at least 175 g/eq and an epoxy functionality of at least 3, and wherein the novolac resin is a polycondensation product of formaldehyde with phenol and/or cresol; and c) 0 to 70 wt % of an epoxy group-containing reaction product of epichlorohydrin with at least one bisphenol, which has an epoxy equivalent weight of at least 500 g/eq; wherein the wt % is based on the mass of all epoxy resins.