Amine-epoxy resin addition product

An epoxy resin composition comprising

• a resin component comprising at least one epoxy resin and
• a curing agent component comprising an adduct from the reaction of
• (i) at least one diamine that is N-benzylethane-1,2-diamine, with
• (ii) at least one aromatic diepoxide, the at least one aromatic diepoxide having an epoxide equivalent weight of from 156 to 200 g/equiv, in a stoichiometric ratio within a range from 1.3 to 1.7 moles of diamine to 1 molar equivalent of epoxy groups,
• wherein the adduct includes 2:1 adducts derived from 2 moles of N-benzylethane-1,2-diamine and 1 mole of the aromatic diepoxide, and higher adducts selected from the group consisting of one or more of 3:2 adducts derived from 3 moles of N-benzylethane-1,2-diamine and 2 moles of the aromatic diepoxide, 4:3 adducts derived from 4 moles of N-benzylethane-1,2-diamine and 3 moles of the aromatic diepoxide, and 5:4 adducts derived from 5 moles of N-benzylethane-1,2-diamine and 4 moles of the aromatic diepoxide, wherein a weight ratio of the 2:1 adducts to the higher adducts is within a range from 30/70 to 49.9/50.1, and
• wherein the adduct has a viscosity at 20° C. within a range from 50 to 500 Pa·s, measured using a cone-plate viscometer at a shear rate of 10 s−1.