PURPOSE: To obtain the title fiber having excellent flexibility and anti- environmental capability by composing a core component of a photopolymerized polymer of a photocurable liquid resin contg. silicone poly(meth)acrylate having ≥2 (meth)acryloyl groups in one molecule, as a main component, and by composing a sheath component of a specific org. polymer respectively.
CONSTITUTION: The core component is the photopolymerized polymer (A) composed of the photocurable liquid resin contg. silicone poly(meth)acrylate having ≥2 (meth)acryloyl groups in the one molecule as the main component. The sheath component is composed of the org. polymer (B) which has a refractive index lower than that of the core component by ≥0.01 and is substantially transparence and has the good flexibility. The silicone poly(meth)acrylate is preferably composed of a condensate of polymethyl phenyl methoxy siloxane and 2-hydroxy ethyl methacrylate, and has the high refractive index and the high transparence, and gives the core material having he good flexibility and heat-resisting property.
FUKUSHIMA HIROSHI