| 摘要 |
PURPOSE:To provide a low loss and high numerical aperture and to improve heat resistance, mechanical characteristics, workability, flexibility, etc., by forming a sheath of a specific vinylidene fluoride/trifluoroethylene/hexafluo roacetone copolymer. CONSTITUTION:The sheath is formed of the vinylidene fluoride/trifluoroethylene/ hexafluoroacetone copolymer in which the content of the hexafluoroacetone unit is 3.5-6.5mol.%, the content ratio of the vinylidene fluoride with respect to the trifluoroethylene unit is 3-6 molar ratio and the melt index is in a 10-60g/10min range. The sheath for plastic optical fibers which has the good compatibility adhesiveness to the fiber, a low refractive index and the excellent transparency and mechanical characteristics as well as the plastic optical fiber which is formed by using said sheath and has the low loss and high numerical aperture as well as the excellent mechanical characteristics, workability, etc., are thereby obtd. |
