| 摘要 |
PURPOSE:To obtain an optical fiber excellent in its strength and flexibility without lowering its light transmission performance by using a polymer shown by the formula as a core and a polymer having perfluoro (2,1-dimethyl-1,3-dioxol) as its main monomer as a sheath, satisfying the condition for specifying a glass transition temperature difference, and providing a protective layer around the periphery. CONSTITUTION:A polymer, shown by the formula, having alkyl ester fluoride of alpha,beta-unsaturated monocarboxylic acid as its main constituent is used as a core, and a copolymer of perfluoro(2,2-dimethyl-1,3-dioxol) and at least one copolymerizable ethylene unsaturated monomer is used as a sheath. The difference in glass transition temperature between the core material and the sheath material is made less than 30 deg.C. Further a protective layer is provided around the periphery. Because of this three-layered structure, adhesiveness between the core and the sheath is secured, so that the light transmission characteristic is improved remarkably and its excellent flexibility is obtained. |
