l diacrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, hexanediol dimethacrylate, trimethylol propane trimethacrylate and compounds in which the terminal hydroxyl group of Bisphenol A or of alkylene oxide adduct of Bisphenol A is esterified with acrylic acid or methacrylic acid; styrene or derivatives thereof such as styrene, chlorostyre