late), trimethylolpropane diacrylate (or methacrylate), acryl-modified urethane elastomers, and derivatives of these having a functional group such as COOH incorporated therein, phenol ethylene oxide adduct acrylate (or methacrylate), compounds in which an acryl or methacryl group or ??-caprolactone acryl group attached to a pentaerythritol fused ring as disclosed in Japanese Patent Application No