PRODUCTION OF OPTICAL TRANSMISSION FIBER

摘要

PURPOSE:To obtain an optical transmission fiber which is decreased in the coloration in a short wavelength region of <=700nm and has a good optical transmission characteristic by spinning a polymer obtd. by a suspension polymn. method in substantially the absence of oxygen. CONSTITUTION:A core component polymer is spun in substantially the absence of oxygen if the polymer obtd. by the suspension polymn. method is used as a core component and a transparent polymer having the refractive index smaller by at least 3% than the refractive index of the core component polymer is used as a sleeve component. The representative polymer to be used as the core component is exemplified by a methyl methacrylate polymer and is also exemplified by a copolymer of a methyl methacrylate and other polymerizable monomers and styrene polymer. Composite spinning is executed in substantially the absence of oxygen. A more preferable method thereof includes a method of putting the system where the core component polymer prior to melting by heating exists into the state where there is substantially no oxygen by a pressure reduction or substitution with an inert gas.