Resin composition for cladding optical fiber

PURPOSE: To provide the subject composition which gives a tough cured composition having extremely high rigidity and has a low cure shrinkage. CONSTITUTION: A resin composition for optical-fiber cladding comprises a radical-curable compound (I) obtained by the reaction of an isocyanuric acid derivative having at the terminal a polymerizable unsaturated group and a hydroxyl group, a polyisocyanate (a), with a compound (b) having at the terminal a polymerizable unsaturated group and a hydroxyl group. Another resin composition for optical-fiber cladding comprises the compound (I) and either an epoxy acrylate or an urethane acrylate obtained by the reaction of the compounds (a) and (b) with a polyol. Each composition further contains a polymerizable diluent and/or a phorosensitizer. There compositions are useful in producing an ultrahigh-density, multi-core optical fiber cable. COPYRIGHT: (C)1993,JPO&Japio