Patent ID: 8242202

Claim:
A curable liquid resin composition comprising the following components (A), (B), (C), (D), and (E): (A) a urethane (meth)acrylate obtained from a diol compound, an aromatic diisocyanate compound in an amount of 1.1-1.8 molar equivalents for one mol of the diol compound, and a hydroxyl group-containing (meth)acrylate compound; (B) 2-ethylhexyl acrylate; (C) a polymerization initiator; (D) a silane coupling agent; and (E) a polymerizable unsaturated monomer which is a lactam containing a vinyl group; wherein the diol compound in component (A) is a polyether diol having an average molecular weight of 1,000-5,000, which is a ring-opening polymer of one or more ion-polymerizable cyclic compounds having 2-4 carbon atoms; wherein the stress-relaxation time, which is defined as the time required for the stress to decline to 37% of the initial stress when a tensile strain of 5% is applied to the cured resin composition at a humidity of 50%, is 10 minutes or less; and wherein said hydroxyl group-containing (meth)acrylate compound is in an amount which is 0.1 to 0.7 equivalent for one equivalent of the hydroxyl group of the diol compound.