METHOD FOR PREPARING CARBON FIBER AND PRECURSOR FIBER FOR CARBON FIBER

摘要

The method for preparing a carbon fiber of the present invention comprises the following steps: preparing a polyacrylonitrile-based polymer solution; spinning the spinning solution containing a polyacrylonitrile-based polymer to prepare a precursor fiber for a carbon fiber having a water content of 20-50 %; converting the precursor fiber for a carbon fiber into a pre-oxidation fiber while stretching the precursor fiber for a carbon fiber at a ratio of -10 to -0.1 % or 0.1 to 5 % at 180-220 ? in an air environment; converting the precursor fiber for a carbon fiber into an oxidation fiber while stretching the precursor fiber for a carbon fiber converted into the pre-oxidation fiber at an elongation of -5 to 5 % at 200-300 ? in an air environment; and heating the oxidation fiber under inert atmosphere to carbonize the same.