To obtain a composition capable of producing an acrylic resin having excellent impact resistance.

This curing composition comprises methyl methacrylate and the dimethacrylate of a dimerdiol-alkylene oxide adduct. The dimethacrylate of the dimerdiol-alkylene oxide adduct includes various compounds, and is preferably the dimethacrylate of a dimerdiol-alkylene oxide adduct (hereinafter referred to as a modified diol) represented by the general formula: HO-(XO)m- ZO-(YO)n-H [Z is a dimerdiol residue; X and Y are each the same or different 2-4C alkylene group; (m), (n) are each 0 or the same or different integer, provided that 2≤(m)+(n)≤40].