METHOD FOR PRODUCING CARBON FIBER PRECURSOR, CARBON FIBER BUNDLE, AND METHOD FOR PRODUCING THE SAME

PROBLEM TO BE SOLVED: To provide a polyacrylonitrile (PAN)-based polymer which can increase spinning speed and can increase a spinning draft rate, to provide a method for producing carbon fiber precursors reduced in fuzz and having a high quality by using the PAN-based polymer, and to provide a method for producing the carbon fibers, by which the carbon fibers having a high quality can stably be produced from the carbon fiber precursors having the high quality even in a calcination process. SOLUTION: A method for producing the carbon fiber precursors includes extruding a spinning solution from a spinneret to obtain the carbon fiber precursors, wherein the spinning solution is prepared by dissolving a polyacrylonitrile-based polymer having a ratio Mz+1/Mw of Z+1 average molecular weight (Mz+1) to weight average molecular weight (Mw) of not less than 6, in a solvent in a concentration of 5 to 30 wt.%, and has a complex viscosity η index of 30 to 150 Pa s at a measurement temperature of 35°C and a measurement angular velocity of 0.05 rad/s, and a storage elastic modulus of 0.1 to 2 Pa at a measurement temperature of 35°C and a measurement angular velocity of 0.05 rad/s. A method for producing the carbon fibers, includes calcining the carbon fiber precursors obtained by the method for producing the carbon fiber precursors. COPYRIGHT: (C)2010,JPO&INPIT