| 摘要 |
PURPOSE:To produce easily an optical fiber having a high strength, by spinning a base material for the optical fiber having a coating layer of an inorganic type adhesive on the outer periphery thereof. CONSTITUTION:An inorganic type adhesive consisting of a thermosetting resin and an inorganic substance, e.g. alumina, is applied to the outer periphery of a base material 1 for an optical fiber 4 to form a coating layer 2 of several hundreds of mum thickness. The resultant base material 1 for the optical fiber 4 is then heated at 500-600 deg.C and hardened. The base material 1 is then introduced into a spinning furnace 3 heated at 1,700-2,000 deg.C and spun into the optical fiber 4, which is then introduced into a coating bath 5 to form a new coating film 6. Thus, the surface flaws will not be caused in the optical fiber 4 during or after the spinning, and a protective film having a high reliability without peeling due to the firm adhesion of the coating layer 2 to the glassy part of the optical fiber 4 is obtained. |
