LIGHT CURING COMPOSITION

摘要

This invention provides a photocuring resin composition comprising (A) a urethane modified (meth)acrylate obtained by reacting (a) a mixture of a polytetramethylene glycol having a molecular weight of not less than 850 and a compound represented by the general formula HO(CH2)3 SIMILAR 8OH, (b) a diisocyanate compound and (c) a (meth)acrylic ester having hydroxyl group, (B) a monofunctional (meth)acrylate or the like, and (C) a photopolymerization initiator. Use of the composition permits formation of a secondary covering layer of optical fibers which has a well-balanced elastic modulus and elongation and is excellent in heat and water resistance.