| 摘要 |
PURPOSE:To obtain excellent light transmittable performance by using a polymer consisting essentially of a monomer composed of a specific styrene deriv. or monomer mixture as a core and a polymer having the refractive index lower than the refractive index of the core polymer as a sleeve. CONSTITUTION:A polymer of a monomer contg. >=60mol% the monomer composed of at least one kind of the styrene deriv. expressed by the formula or a monomer mixture is used for the core of a plastic optical fiber having a core and sleeve structure and the polymer having the refractive index lower than the refractive index of the core polymer is used as the sleeve. Such styrene deriv. can be thermally polymerized even if a polymn. initiator is not added and therefore the pure polymer is easily obtainable. The resulting polymer has a high glass transition temp. and good heat resistance. The polymer polymerized with the monomers mixed with >=60mol%, more preferably >=80mol% such monomer decreases scattering owing to fluctuation. The excellent optical fiber is obtainable by decreasing the dissolved oxygen in the monomer. A mass polymn. is preferable as a polymn. method and the optical fiber having excellent flexibility, etc. is obtd. by, for example, extrusion simultaneously with melting, etc. of the core polymer and the sleeve polymer. |
