| 摘要 |
PURPOSE:To obtain a plastic optical fiber having a low transmission loss by using specific polycarbonate as a fiber component and specifying a melt-spinning stage. CONSTITUTION:The polycarbonate having >=0.40dl/g and <0.60dl/g ultimate viscosity (20 deg.C in methylene chloride) is used as the fiber component. After the polycarbonate is once completely melted at >=260 deg.C in the melt-spinning stage, the molten polycarbonate is discharged from a spinning munthpiece without cooling the same down to the (m.p. of the crystal -20 deg.C) or below an is run for >=10cm length under the mouthpiece in a slow cooling region held at >=70 deg.C. The polycarbonate to be used in this embodiment is produced generally by bringing dihydric phenol and carbonate precursor such as phosgene into reaction. The resulted polycarbonate optical fiber has the good transmission loss and the uniformity of the fiber diameter in combination and is capable of greatly expanding the applications as the fiber for light transmission. |
