Disclosed herein is a composition comprising: an epoxy-containing component, elastomeric particles in an amount of greater than 11% by weight to 25% by weight based on total weight of the composition; and a curing component activatable by an external energy source, the curing component comprising at least one guanidine having a D90 particle size of 25 m measured by dynamic light scattering. Also disclosed is the composition in an at least partially cured state. Also disclosed is a method for treating a substrate comprising applying the composition to a surface of a substrate; and applying an external energy source to cure the composition. Also disclosed are substrates comprising the composition. Also disclosed are substrates formed by the method of the present invention.

Provided herein is a hardener composition comprising (a) a first adduct comprising a reaction product of a liquid epoxy resin and isophorone diamine; (b) a second adduct comprising a reaction product of a liquid epoxy resin and m-xylylenediamine; and (c) an accelerator component comprising methanesulfonic acid.