| 摘要 |
PURPOSE:To obtain a polymer having a high glass transition point and large fracture ductility of film, and superiority in transparency, by composing a copolymer having perfluoro (2.2-dimethyl-1-1,3-dioxol) as its main monomer and a perfluoro compound and so forth. CONSTITUTION:A sheath composition for optical fiber comprises 50-99wt. parts of a copolymer having copolymerization of more than 30mol% of perfluoro (2,2-dimethyl-1,3-dioxol) and 1-50wt. parts of perfluoro polymer composed of a cyclic perfluoro compound containing at least one or more fluorooxyalkylene group in its structure or a cyclic structure containing at least one or more fluorooxyalkylene group per cyclic structure. Perfluoro (2-butyltetrahydrofuran) having perfluoro (tetrahydrofuran) or an alkyl group in its side chain, or the like, is available as the cyclic perfluoro compound having a fluorooxyalkylene group. Accordingly, a sheath highly transparent, excellent in heat resistance and solvent resistance, with a high fracture ductility, can be formed. |
