UV-ray curable polyurethane composition and coated optical fiber

摘要

A UV-ray curable resin composition comprising a polyurethane derived from a polyether polyol and a diene polymer having hydroxyl group, said polyurethane having polymerizable double bond different from the carbon-carbon double bonds contained in said diene polymer having hydroxyl group, and a coated optical fiber having a coated layer comprising the cured product of said resin composition. This composition has good coating characteristics, and the cured product thereof has small modulus over a wide temperature range and good hydrolysis resistance, and water absorption resistance. The coated optical fiber has small transmission loss over a wide temperature range and has high strength even in water.