| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing carbon fiber precursor fiber improving spinning rate, directing reduction of carbon fiber cost and providing a high strength carbon fiber by accurately filtering foreign matters without causing filter blocked out, before discharging PAN-based polymer for producing carbon fiber precursor fiber from a spinneret. SOLUTION: The method for producing carbon fiber precursor fiber includes filtration of a spinning solution obtained by solving a polyacrylonitrile based polymer with 1.5 or more of Mz/Mw which is a ratio of z average molecular weight Mz and a weight average molecular weight Mw, in a solvent, before spinning, wherein the filtration is performed by using a filtering device using a filtering member composed of a certified filtering layer (with smallest opening diameter) in which the basis weight of the certified filtering layer A (g/m<SP>2</SP>) and the density of material B (g/m<SP>3</SP>) satisfy formula: 0.01≤A/B×1000≤0.06, and having a filtration resistance coefficient of 5×10<SP>5</SP>to 30×10<SP>5</SP>cm<SP>-1</SP>. COPYRIGHT: (C)2010,JPO&INPIT |
