PURPOSE: To obtain the subject composition having rapid development of strength at ordinary temperature, capable of providing a cured material hardly having residual styrene, excellent in impact resistance and toughness and useful as a lining material.

CONSTITUTION: This composition contains (A) 100 pts.wt. of a resin composition consisting of (i) 30-75wt.% of a modified butadiene-acrylonitrile copolymer having a (meth)acryloyl group or a vinyl group at the end and (ii) 25-70wt.% of a radically polymerizable unsaturated monomer, (B) 0.05-5 pts.wt. of amines of the formula [R1 is H, CH3 or C2H5; R2 is CnH2n; (n) is 1-5] (e.g. N- phenylethanolamine) and (C) 0.5-10 pts.wt. of a diacylperoxide (e.g. lauroyl peroxide).